#include <mach/memory_object_control_server.h>
#include <mach/vm_param.h>
+#include <mach/sdt.h>
+
#include <ipc/ipc_types.h>
#include <ipc/ipc_port.h>
#include <kern/kern_types.h>
#include <kern/assert.h>
-#include <kern/lock.h>
#include <kern/queue.h>
#include <kern/xpr.h>
+#include <kern/kalloc.h>
#include <kern/zalloc.h>
#include <kern/host.h>
#include <kern/host_statistics.h>
#include <kern/processor.h>
#include <kern/misc_protos.h>
+#include <kern/policy_internal.h>
#include <vm/memory_object.h>
+#include <vm/vm_compressor_pager.h>
#include <vm/vm_fault.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_protos.h>
#include <vm/vm_purgeable_internal.h>
-#if CONFIG_EMBEDDED
-#include <sys/kern_memorystatus.h>
+#include <vm/vm_compressor.h>
+
+#if CONFIG_PHANTOM_CACHE
+#include <vm/vm_phantom_cache.h>
#endif
+boolean_t vm_object_collapse_compressor_allowed = TRUE;
+
+struct vm_counters vm_counters;
+
+#if VM_OBJECT_TRACKING
+boolean_t vm_object_tracking_inited = FALSE;
+btlog_t *vm_object_tracking_btlog;
+
+void
+vm_object_tracking_init(void)
+{
+ int vm_object_tracking;
+
+ vm_object_tracking = 1;
+ PE_parse_boot_argn("vm_object_tracking", &vm_object_tracking,
+ sizeof (vm_object_tracking));
+
+ if (vm_object_tracking) {
+ vm_object_tracking_btlog = btlog_create(
+ VM_OBJECT_TRACKING_NUM_RECORDS,
+ VM_OBJECT_TRACKING_BTDEPTH,
+ TRUE /* caller_will_remove_entries_for_element? */);
+ assert(vm_object_tracking_btlog);
+ vm_object_tracking_inited = TRUE;
+ }
+}
+#endif /* VM_OBJECT_TRACKING */
+
/*
* Virtual memory objects maintain the actual data
* associated with allocated virtual memory. A given
* All wired-down kernel memory belongs to a single virtual
* memory object (kernel_object) to avoid wasting data structures.
*/
-static struct vm_object kernel_object_store;
-vm_object_t kernel_object;
+static struct vm_object kernel_object_store __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
+vm_object_t kernel_object;
+static struct vm_object compressor_object_store __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
+vm_object_t compressor_object = &compressor_object_store;
/*
* The submap object is used as a placeholder for vm_map_submap
* is exported by the vm_map module. The storage is declared
* here because it must be initialized here.
*/
-static struct vm_object vm_submap_object_store;
+static struct vm_object vm_submap_object_store __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
/*
* Virtual memory objects are initialized from
static vm_object_t vm_object_cache_trim(
boolean_t called_from_vm_object_deallocate);
-static queue_head_t vm_object_cached_list;
-static int vm_object_cached_count=0;
+static void vm_object_deactivate_all_pages(
+ vm_object_t object);
+
static int vm_object_cached_high; /* highest # cached objects */
static int vm_object_cached_max = 512; /* may be patched*/
-static lck_mtx_t vm_object_cached_lock_data;
-static lck_mtx_ext_t vm_object_cached_lock_data_ext;
-
#define vm_object_cache_lock() \
lck_mtx_lock(&vm_object_cached_lock_data)
#define vm_object_cache_lock_try() \
lck_mtx_try_lock(&vm_object_cached_lock_data)
+
+#endif /* VM_OBJECT_CACHE */
+
+static queue_head_t vm_object_cached_list;
+static uint32_t vm_object_cache_pages_freed = 0;
+static uint32_t vm_object_cache_pages_moved = 0;
+static uint32_t vm_object_cache_pages_skipped = 0;
+static uint32_t vm_object_cache_adds = 0;
+static uint32_t vm_object_cached_count = 0;
+static lck_mtx_t vm_object_cached_lock_data;
+static lck_mtx_ext_t vm_object_cached_lock_data_ext;
+
+static uint32_t vm_object_page_grab_failed = 0;
+static uint32_t vm_object_page_grab_skipped = 0;
+static uint32_t vm_object_page_grab_returned = 0;
+static uint32_t vm_object_page_grab_pmapped = 0;
+static uint32_t vm_object_page_grab_reactivations = 0;
+
#define vm_object_cache_lock_spin() \
lck_mtx_lock_spin(&vm_object_cached_lock_data)
#define vm_object_cache_unlock() \
lck_mtx_unlock(&vm_object_cached_lock_data)
-#endif /* VM_OBJECT_CACHE */
-
-
-static void vm_object_deactivate_all_pages(
- vm_object_t object);
+static void vm_object_cache_remove_locked(vm_object_t);
#define VM_OBJECT_HASH_COUNT 1024
#define VM_OBJECT_HASH_LOCK_COUNT 512
-static lck_mtx_t vm_object_hashed_lock_data[VM_OBJECT_HASH_COUNT];
-static lck_mtx_ext_t vm_object_hashed_lock_data_ext[VM_OBJECT_HASH_COUNT];
+static lck_mtx_t vm_object_hashed_lock_data[VM_OBJECT_HASH_LOCK_COUNT];
+static lck_mtx_ext_t vm_object_hashed_lock_data_ext[VM_OBJECT_HASH_LOCK_COUNT];
static queue_head_t vm_object_hashtable[VM_OBJECT_HASH_COUNT];
static struct zone *vm_object_hash_zone;
#define vm_object_reaper_unlock() \
lck_mtx_unlock(&vm_object_reaper_lock_data)
+#if CONFIG_IOSCHED
+/* I/O Re-prioritization request list */
+queue_head_t io_reprioritize_list;
+lck_spin_t io_reprioritize_list_lock;
+
+#define IO_REPRIORITIZE_LIST_LOCK() \
+ lck_spin_lock(&io_reprioritize_list_lock)
+#define IO_REPRIORITIZE_LIST_UNLOCK() \
+ lck_spin_unlock(&io_reprioritize_list_lock)
+
+#define MAX_IO_REPRIORITIZE_REQS 8192
+zone_t io_reprioritize_req_zone;
+
+/* I/O Re-prioritization thread */
+int io_reprioritize_wakeup = 0;
+static void io_reprioritize_thread(void *param __unused, wait_result_t wr __unused);
+
+#define IO_REPRIO_THREAD_WAKEUP() thread_wakeup((event_t)&io_reprioritize_wakeup)
+#define IO_REPRIO_THREAD_CONTINUATION() \
+{ \
+ assert_wait(&io_reprioritize_wakeup, THREAD_UNINT); \
+ thread_block(io_reprioritize_thread); \
+}
+
+void vm_page_request_reprioritize(vm_object_t, uint64_t, uint32_t, int);
+void vm_page_handle_prio_inversion(vm_object_t, vm_page_t);
+void vm_decmp_upl_reprioritize(upl_t, int);
+#endif
+
+#if 0
+#undef KERNEL_DEBUG
+#define KERNEL_DEBUG KERNEL_DEBUG_CONSTANT
+#endif
static lck_mtx_t *
{
queue_t bucket;
+ assert(vm_object_hash_lookup(entry->pager, FALSE) == NULL);
+
bucket = &vm_object_hashtable[vm_object_hash(entry->pager)];
queue_enter(bucket, entry, vm_object_hash_entry_t, hash_link);
+ if (object->hashed) {
+ /*
+ * "hashed" was pre-set on this (new) object to avoid
+ * locking issues in vm_object_enter() (can't attempt to
+ * grab the object lock while holding the hash lock as
+ * a spinlock), so no need to set it here (and no need to
+ * hold the object's lock).
+ */
+ } else {
+ vm_object_lock_assert_exclusive(object);
+ object->hashed = TRUE;
+ }
+
entry->object = object;
- object->hashed = TRUE;
}
static vm_object_hash_entry_t
object, size, 0,0,0);
*object = vm_object_template;
- queue_init(&object->memq);
+ vm_page_queue_init(&object->memq);
queue_init(&object->msr_q);
-#if UPL_DEBUG
+#if UPL_DEBUG || CONFIG_IOSCHED
queue_init(&object->uplq);
-#endif /* UPL_DEBUG */
+#endif
vm_object_lock_init(object);
- object->size = size;
+ object->vo_size = size;
+
+#if VM_OBJECT_TRACKING_OP_CREATED
+ if (vm_object_tracking_inited) {
+ void *bt[VM_OBJECT_TRACKING_BTDEPTH];
+ int numsaved = 0;
+
+ numsaved = OSBacktrace(bt, VM_OBJECT_TRACKING_BTDEPTH);
+ btlog_add_entry(vm_object_tracking_btlog,
+ object,
+ VM_OBJECT_TRACKING_OP_CREATED,
+ bt,
+ numsaved);
+ }
+#endif /* VM_OBJECT_TRACKING_OP_CREATED */
}
__private_extern__ vm_object_t
vm_object_allocate(
vm_object_size_t size)
{
- register vm_object_t object;
+ vm_object_t object;
object = (vm_object_t) zalloc(vm_object_zone);
lck_grp_t vm_object_lck_grp;
-lck_grp_attr_t vm_object_lck_grp_attr;
+lck_grp_t vm_object_cache_lck_grp;
+lck_grp_attr_t vm_object_lck_grp_attr;
lck_attr_t vm_object_lck_attr;
lck_attr_t kernel_object_lck_attr;
+lck_attr_t compressor_object_lck_attr;
/*
* vm_object_bootstrap:
__private_extern__ void
vm_object_bootstrap(void)
{
- register int i;
+ int i;
+ vm_size_t vm_object_size;
- vm_object_zone = zinit((vm_size_t) sizeof(struct vm_object),
- round_page(512*1024),
- round_page(12*1024),
- "vm objects");
+ vm_object_size = (sizeof(struct vm_object) + (VM_PACKED_POINTER_ALIGNMENT-1)) & ~(VM_PACKED_POINTER_ALIGNMENT - 1);
+
+ vm_object_zone = zinit(vm_object_size,
+ round_page(512*1024),
+ round_page(12*1024),
+ "vm objects");
+ zone_change(vm_object_zone, Z_CALLERACCT, FALSE); /* don't charge caller */
+ zone_change(vm_object_zone, Z_NOENCRYPT, TRUE);
vm_object_init_lck_grp();
-#if VM_OBJECT_CACHE
queue_init(&vm_object_cached_list);
lck_mtx_init_ext(&vm_object_cached_lock_data,
&vm_object_cached_lock_data_ext,
- &vm_object_lck_grp,
+ &vm_object_cache_lck_grp,
&vm_object_lck_attr);
-#endif
+
queue_init(&vm_object_reaper_queue);
for (i = 0; i < VM_OBJECT_HASH_LOCK_COUNT; i++) {
round_page(512*1024),
round_page(12*1024),
"vm object hash entries");
+ zone_change(vm_object_hash_zone, Z_CALLERACCT, FALSE);
+ zone_change(vm_object_hash_zone, Z_NOENCRYPT, TRUE);
for (i = 0; i < VM_OBJECT_HASH_COUNT; i++)
queue_init(&vm_object_hashtable[i]);
*/
/* memq; Lock; init after allocation */
- vm_object_template.memq.prev = NULL;
- vm_object_template.memq.next = NULL;
+
+
+ vm_object_template.memq.prev = 0;
+ vm_object_template.memq.next = 0;
#if 0
/*
* We can't call vm_object_lock_init() here because that will
*/
vm_object_lock_init(&vm_object_template);
#endif
- vm_object_template.size = 0;
+#if DEVELOPMENT || DEBUG
+ vm_object_template.Lock_owner = 0;
+#endif
+ vm_object_template.vo_size = 0;
vm_object_template.memq_hint = VM_PAGE_NULL;
vm_object_template.ref_count = 1;
#if TASK_SWAPPER
vm_object_template.reusable_page_count = 0;
vm_object_template.copy = VM_OBJECT_NULL;
vm_object_template.shadow = VM_OBJECT_NULL;
- vm_object_template.shadow_offset = (vm_object_offset_t) 0;
+ vm_object_template.vo_shadow_offset = (vm_object_offset_t) 0;
vm_object_template.pager = MEMORY_OBJECT_NULL;
vm_object_template.paging_offset = 0;
vm_object_template.pager_control = MEMORY_OBJECT_CONTROL_NULL;
vm_object_template.copy_strategy = MEMORY_OBJECT_COPY_SYMMETRIC;
vm_object_template.paging_in_progress = 0;
+#if __LP64__
+ vm_object_template.__object1_unused_bits = 0;
+#endif /* __LP64__ */
vm_object_template.activity_in_progress = 0;
/* Begin bitfields */
vm_object_template.pageout = FALSE;
vm_object_template.alive = TRUE;
vm_object_template.purgable = VM_PURGABLE_DENY;
+ vm_object_template.purgeable_when_ripe = FALSE;
vm_object_template.shadowed = FALSE;
- vm_object_template.silent_overwrite = FALSE;
vm_object_template.advisory_pageout = FALSE;
vm_object_template.true_share = FALSE;
vm_object_template.terminating = FALSE;
vm_object_template.sequential = (vm_object_offset_t) 0;
vm_object_template.pages_created = 0;
vm_object_template.pages_used = 0;
-
-#if MACH_PAGEMAP
- vm_object_template.existence_map = VM_EXTERNAL_NULL;
-#endif /* MACH_PAGEMAP */
+ vm_object_template.scan_collisions = 0;
+#if CONFIG_PHANTOM_CACHE
+ vm_object_template.phantom_object_id = 0;
+#endif
vm_object_template.cow_hint = ~(vm_offset_t)0;
#if MACH_ASSERT
vm_object_template.paging_object = VM_OBJECT_NULL;
#endif /* MACH_ASSERT */
/* cache bitfields */
- vm_object_template.wimg_bits = VM_WIMG_DEFAULT;
+ vm_object_template.wimg_bits = VM_WIMG_USE_DEFAULT;
+ vm_object_template.set_cache_attr = FALSE;
+ vm_object_template.object_slid = FALSE;
vm_object_template.code_signed = FALSE;
vm_object_template.hashed = FALSE;
vm_object_template.transposed = FALSE;
vm_object_template.mapping_in_progress = FALSE;
+ vm_object_template.phantom_isssd = FALSE;
vm_object_template.volatile_empty = FALSE;
vm_object_template.volatile_fault = FALSE;
vm_object_template.all_reusable = FALSE;
vm_object_template.blocked_access = FALSE;
vm_object_template.__object2_unused_bits = 0;
-#if UPL_DEBUG
+#if CONFIG_IOSCHED || UPL_DEBUG
vm_object_template.uplq.prev = NULL;
vm_object_template.uplq.next = NULL;
#endif /* UPL_DEBUG */
sizeof (vm_object_template.pip_holders));
#endif /* VM_PIP_DEBUG */
- vm_object_template.objq.next=NULL;
- vm_object_template.objq.prev=NULL;
+ vm_object_template.objq.next = NULL;
+ vm_object_template.objq.prev = NULL;
+
+ vm_object_template.purgeable_queue_type = PURGEABLE_Q_TYPE_MAX;
+ vm_object_template.purgeable_queue_group = 0;
+
+ vm_object_template.vo_cache_ts = 0;
+
+ vm_object_template.wire_tag = VM_KERN_MEMORY_NONE;
+ vm_object_template.io_tracking = FALSE;
+
+#if CONFIG_SECLUDED_MEMORY
+ vm_object_template.eligible_for_secluded = FALSE;
+ vm_object_template.can_grab_secluded = FALSE;
+#else /* CONFIG_SECLUDED_MEMORY */
+ vm_object_template.__object3_unused_bits = 0;
+#endif /* CONFIG_SECLUDED_MEMORY */
+#if DEBUG
+ bzero(&vm_object_template.purgeable_owner_bt[0],
+ sizeof (vm_object_template.purgeable_owner_bt));
+ vm_object_template.vo_purgeable_volatilizer = NULL;
+ bzero(&vm_object_template.purgeable_volatilizer_bt[0],
+ sizeof (vm_object_template.purgeable_volatilizer_bt));
+#endif /* DEBUG */
+
/*
* Initialize the "kernel object"
*/
* VM_MAX_KERNEL_ADDRESS (vm_last_addr) is a maximum address, not a size.
*/
-#ifdef ppc
- _vm_object_allocate(vm_last_addr + 1,
- kernel_object);
-#else
_vm_object_allocate(VM_MAX_KERNEL_ADDRESS + 1,
kernel_object);
-#endif
+
+ _vm_object_allocate(VM_MAX_KERNEL_ADDRESS + 1,
+ compressor_object);
kernel_object->copy_strategy = MEMORY_OBJECT_COPY_NONE;
+ compressor_object->copy_strategy = MEMORY_OBJECT_COPY_NONE;
/*
* Initialize the "submap object". Make it as large as the
*/
vm_submap_object = &vm_submap_object_store;
-#ifdef ppc
- _vm_object_allocate(vm_last_addr + 1,
- vm_submap_object);
-#else
_vm_object_allocate(VM_MAX_KERNEL_ADDRESS + 1,
vm_submap_object);
-#endif
vm_submap_object->copy_strategy = MEMORY_OBJECT_COPY_NONE;
/*
* non-zone memory.
*/
vm_object_reference(vm_submap_object);
+}
-#if MACH_PAGEMAP
- vm_external_module_initialize();
-#endif /* MACH_PAGEMAP */
+#if CONFIG_IOSCHED
+void
+vm_io_reprioritize_init(void)
+{
+ kern_return_t result;
+ thread_t thread = THREAD_NULL;
+
+ /* Initialze the I/O reprioritization subsystem */
+ lck_spin_init(&io_reprioritize_list_lock, &vm_object_lck_grp, &vm_object_lck_attr);
+ queue_init(&io_reprioritize_list);
+
+ io_reprioritize_req_zone = zinit(sizeof(struct io_reprioritize_req),
+ MAX_IO_REPRIORITIZE_REQS * sizeof(struct io_reprioritize_req),
+ 4096, "io_reprioritize_req");
+
+ result = kernel_thread_start_priority(io_reprioritize_thread, NULL, 95 /* MAXPRI_KERNEL */, &thread);
+ if (result == KERN_SUCCESS) {
+ thread_deallocate(thread);
+ } else {
+ panic("Could not create io_reprioritize_thread");
+ }
}
+#endif
void
vm_object_reaper_init(void)
*/
lck_grp_attr_setdefault(&vm_object_lck_grp_attr);
lck_grp_init(&vm_object_lck_grp, "vm_object", &vm_object_lck_grp_attr);
+ lck_grp_init(&vm_object_cache_lck_grp, "vm_object_cache", &vm_object_lck_grp_attr);
lck_attr_setdefault(&vm_object_lck_attr);
lck_attr_setdefault(&kernel_object_lck_attr);
lck_attr_cleardebug(&kernel_object_lck_attr);
+ lck_attr_setdefault(&compressor_object_lck_attr);
+ lck_attr_cleardebug(&compressor_object_lck_attr);
}
#if VM_OBJECT_CACHE
unsigned long vm_object_deallocate_shared_successes = 0;
unsigned long vm_object_deallocate_shared_failures = 0;
unsigned long vm_object_deallocate_shared_swap_failures = 0;
+
__private_extern__ void
vm_object_deallocate(
- register vm_object_t object)
+ vm_object_t object)
{
#if VM_OBJECT_CACHE
boolean_t retry_cache_trim = FALSE;
if (object == VM_OBJECT_NULL)
return;
- if (object == kernel_object) {
+ if (object == kernel_object || object == compressor_object) {
vm_object_lock_shared(object);
OSAddAtomic(-1, &object->ref_count);
if (object->ref_count == 0) {
- panic("vm_object_deallocate: losing kernel_object\n");
+ if (object == kernel_object)
+ panic("vm_object_deallocate: losing kernel_object\n");
+ else
+ panic("vm_object_deallocate: losing compressor_object\n");
}
vm_object_unlock(object);
return;
}
- if (object->ref_count > 2 ||
- (!object->named && object->ref_count > 1)) {
+ if (object->ref_count == 2 &&
+ object->named) {
+ /*
+ * This "named" object's reference count is about to
+ * drop from 2 to 1:
+ * we'll need to call memory_object_last_unmap().
+ */
+ } else if (object->ref_count == 2 &&
+ object->internal &&
+ object->shadow != VM_OBJECT_NULL) {
+ /*
+ * This internal object's reference count is about to
+ * drop from 2 to 1 and it has a shadow object:
+ * we'll want to try and collapse this object with its
+ * shadow.
+ */
+ } else if (object->ref_count >= 2) {
UInt32 original_ref_count;
volatile UInt32 *ref_count_p;
Boolean atomic_swap;
* Test again as "ref_count" could have changed.
* "named" shouldn't change.
*/
- if (original_ref_count > 2 ||
- (!object->named && original_ref_count > 1)) {
+ if (original_ref_count == 2 &&
+ object->named) {
+ /* need to take slow path for m_o_last_unmap() */
+ atomic_swap = FALSE;
+ } else if (original_ref_count == 2 &&
+ object->internal &&
+ object->shadow != VM_OBJECT_NULL) {
+ /* need to take slow path for vm_object_collapse() */
+ atomic_swap = FALSE;
+ } else if (original_ref_count < 2) {
+ /* need to take slow path for vm_object_terminate() */
+ atomic_swap = FALSE;
+ } else {
+ /* try an atomic update with the shared lock */
atomic_swap = OSCompareAndSwap(
original_ref_count,
original_ref_count - 1,
(UInt32 *) &object->ref_count);
if (atomic_swap == FALSE) {
vm_object_deallocate_shared_swap_failures++;
+ /* fall back to the slow path... */
}
-
- } else {
- atomic_swap = FALSE;
}
+
vm_object_unlock(object);
if (atomic_swap) {
vm_object_lock(object);
vm_object_mapping_end(object);
}
- /*
- * recheck the ref_count since we dropped the object lock
- * to call 'memory_object_last_unmap'... it's possible
- * additional references got taken and we only want
- * to deactivate the pages if this 'named' object will only
- * referenced by the backing pager once we drop our reference
- * below
- */
- if (!object->terminating && object->ref_count == 2)
- vm_object_deactivate_all_pages(object);
-
assert(object->ref_count > 0);
}
}
-#if VM_OBJECT_CACHE
-/*
- * Check to see whether we really need to trim
- * down the cache. If so, remove an object from
- * the cache, terminate it, and repeat.
- *
- * Called with, and returns with, cache lock unlocked.
- */
-vm_object_t
-vm_object_cache_trim(
- boolean_t called_from_vm_object_deallocate)
+
+vm_page_t
+vm_object_page_grab(
+ vm_object_t object)
{
- register vm_object_t object = VM_OBJECT_NULL;
- vm_object_t shadow;
+ vm_page_t p, next_p;
+ int p_limit = 0;
+ int p_skipped = 0;
- for (;;) {
+ vm_object_lock_assert_exclusive(object);
- /*
- * If we no longer need to trim the cache,
- * then we are done.
- */
- if (vm_object_cached_count <= vm_object_cached_max)
- return VM_OBJECT_NULL;
+ next_p = (vm_page_t)vm_page_queue_first(&object->memq);
+ p_limit = MIN(50, object->resident_page_count);
- vm_object_cache_lock();
- if (vm_object_cached_count <= vm_object_cached_max) {
- vm_object_cache_unlock();
- return VM_OBJECT_NULL;
- }
+ while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next_p) && --p_limit > 0) {
- /*
- * We must trim down the cache, so remove
- * the first object in the cache.
- */
- XPR(XPR_VM_OBJECT,
- "vm_object_cache_trim: removing from front of cache (%x, %x)\n",
- vm_object_cached_list.next,
- vm_object_cached_list.prev, 0, 0, 0);
+ p = next_p;
+ next_p = (vm_page_t)vm_page_queue_next(&next_p->listq);
- object = (vm_object_t) queue_first(&vm_object_cached_list);
- if(object == (vm_object_t) &vm_object_cached_list) {
- /* something's wrong with the calling parameter or */
- /* the value of vm_object_cached_count, just fix */
- /* and return */
- if(vm_object_cached_max < 0)
- vm_object_cached_max = 0;
- vm_object_cached_count = 0;
- vm_object_cache_unlock();
- return VM_OBJECT_NULL;
- }
- vm_object_lock(object);
- queue_remove(&vm_object_cached_list, object, vm_object_t,
- cached_list);
- vm_object_cached_count--;
+ if (VM_PAGE_WIRED(p) || p->busy || p->cleaning || p->laundry || p->fictitious)
+ goto move_page_in_obj;
- vm_object_cache_unlock();
- /*
- * Since this object is in the cache, we know
- * that it is initialized and has no references.
- * Take a reference to avoid recursive deallocations.
- */
+ if (p->pmapped || p->dirty || p->precious) {
+ vm_page_lockspin_queues();
- assert(object->pager_initialized);
- assert(object->ref_count == 0);
- vm_object_lock_assert_exclusive(object);
- object->ref_count++;
+ if (p->pmapped) {
+ int refmod_state;
- /*
- * Terminate the object.
- * If the object had a shadow, we let vm_object_deallocate
- * deallocate it. "pageout" objects have a shadow, but
- * maintain a "paging reference" rather than a normal
- * reference.
- * (We are careful here to limit recursion.)
- */
- shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
+ vm_object_page_grab_pmapped++;
- if(vm_object_terminate(object) != KERN_SUCCESS)
- continue;
+ if (p->reference == FALSE || p->dirty == FALSE) {
- if (shadow != VM_OBJECT_NULL) {
- if (called_from_vm_object_deallocate) {
- return shadow;
- } else {
- vm_object_deallocate(shadow);
+ refmod_state = pmap_get_refmod(VM_PAGE_GET_PHYS_PAGE(p));
+
+ if (refmod_state & VM_MEM_REFERENCED)
+ p->reference = TRUE;
+ if (refmod_state & VM_MEM_MODIFIED) {
+ SET_PAGE_DIRTY(p, FALSE);
+ }
+ }
+ if (p->dirty == FALSE && p->precious == FALSE) {
+
+ refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+
+ if (refmod_state & VM_MEM_REFERENCED)
+ p->reference = TRUE;
+ if (refmod_state & VM_MEM_MODIFIED) {
+ SET_PAGE_DIRTY(p, FALSE);
+ }
+
+ if (p->dirty == FALSE)
+ goto take_page;
+ }
+ }
+ if ((p->vm_page_q_state != VM_PAGE_ON_ACTIVE_Q) && p->reference == TRUE) {
+ vm_page_activate(p);
+
+ VM_STAT_INCR(reactivations);
+ vm_object_page_grab_reactivations++;
}
+ vm_page_unlock_queues();
+move_page_in_obj:
+ vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+ vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
+
+ p_skipped++;
+ continue;
}
+ vm_page_lockspin_queues();
+take_page:
+ vm_page_free_prepare_queues(p);
+ vm_object_page_grab_returned++;
+ vm_object_page_grab_skipped += p_skipped;
+
+ vm_page_unlock_queues();
+
+ vm_page_free_prepare_object(p, TRUE);
+
+ return (p);
}
+ vm_object_page_grab_skipped += p_skipped;
+ vm_object_page_grab_failed++;
+
+ return (NULL);
}
-#endif
-/*
- * Routine: vm_object_terminate
- * Purpose:
- * Free all resources associated with a vm_object.
- * In/out conditions:
- * Upon entry, the object must be locked,
- * and the object must have exactly one reference.
- *
- * The shadow object reference is left alone.
- *
- * The object must be unlocked if its found that pages
- * must be flushed to a backing object. If someone
- * manages to map the object while it is being flushed
- * the object is returned unlocked and unchanged. Otherwise,
- * upon exit, the cache will be unlocked, and the
- * object will cease to exist.
- */
-static kern_return_t
-vm_object_terminate(
+
+#define EVICT_PREPARE_LIMIT 64
+#define EVICT_AGE 10
+
+static clock_sec_t vm_object_cache_aging_ts = 0;
+
+static void
+vm_object_cache_remove_locked(
vm_object_t object)
{
- vm_object_t shadow_object;
+ assert(object->purgable == VM_PURGABLE_DENY);
+ assert(object->wired_page_count == 0);
- XPR(XPR_VM_OBJECT, "vm_object_terminate, object 0x%X ref %d\n",
- object, object->ref_count, 0, 0, 0);
+ queue_remove(&vm_object_cached_list, object, vm_object_t, objq);
+ object->objq.next = NULL;
+ object->objq.prev = NULL;
- if (!object->pageout && (!object->temporary || object->can_persist) &&
- (object->pager != NULL || object->shadow_severed)) {
- /*
- * Clear pager_trusted bit so that the pages get yanked
- * out of the object instead of cleaned in place. This
- * prevents a deadlock in XMM and makes more sense anyway.
- */
- object->pager_trusted = FALSE;
+ vm_object_cached_count--;
+}
- vm_object_reap_pages(object, REAP_TERMINATE);
- }
- /*
- * Make sure the object isn't already being terminated
- */
- if (object->terminating) {
- vm_object_lock_assert_exclusive(object);
- object->ref_count--;
- assert(object->ref_count > 0);
- vm_object_unlock(object);
- return KERN_FAILURE;
- }
+void
+vm_object_cache_remove(
+ vm_object_t object)
+{
+ vm_object_cache_lock_spin();
- /*
- * Did somebody get a reference to the object while we were
- * cleaning it?
- */
- if (object->ref_count != 1) {
- vm_object_lock_assert_exclusive(object);
- object->ref_count--;
- assert(object->ref_count > 0);
- vm_object_res_deallocate(object);
- vm_object_unlock(object);
- return KERN_FAILURE;
- }
+ if (object->objq.next || object->objq.prev)
+ vm_object_cache_remove_locked(object);
- /*
- * Make sure no one can look us up now.
- */
+ vm_object_cache_unlock();
+}
- object->terminating = TRUE;
- object->alive = FALSE;
+void
+vm_object_cache_add(
+ vm_object_t object)
+{
+ clock_sec_t sec;
+ clock_nsec_t nsec;
- if (object->hashed) {
- lck_mtx_t *lck;
+ assert(object->purgable == VM_PURGABLE_DENY);
+ assert(object->wired_page_count == 0);
- lck = vm_object_hash_lock_spin(object->pager);
- vm_object_remove(object);
- vm_object_hash_unlock(lck);
+ if (object->resident_page_count == 0)
+ return;
+ clock_get_system_nanotime(&sec, &nsec);
+
+ vm_object_cache_lock_spin();
+
+ if (object->objq.next == NULL && object->objq.prev == NULL) {
+ queue_enter(&vm_object_cached_list, object, vm_object_t, objq);
+ object->vo_cache_ts = sec + EVICT_AGE;
+ object->vo_cache_pages_to_scan = object->resident_page_count;
+
+ vm_object_cached_count++;
+ vm_object_cache_adds++;
}
+ vm_object_cache_unlock();
+}
+
+int
+vm_object_cache_evict(
+ int num_to_evict,
+ int max_objects_to_examine)
+{
+ vm_object_t object = VM_OBJECT_NULL;
+ vm_object_t next_obj = VM_OBJECT_NULL;
+ vm_page_t local_free_q = VM_PAGE_NULL;
+ vm_page_t p;
+ vm_page_t next_p;
+ int object_cnt = 0;
+ vm_page_t ep_array[EVICT_PREPARE_LIMIT];
+ int ep_count;
+ int ep_limit;
+ int ep_index;
+ int ep_freed = 0;
+ int ep_moved = 0;
+ uint32_t ep_skipped = 0;
+ clock_sec_t sec;
+ clock_nsec_t nsec;
+
+ KERNEL_DEBUG(0x13001ec | DBG_FUNC_START, 0, 0, 0, 0, 0);
/*
- * Detach the object from its shadow if we are the shadow's
- * copy. The reference we hold on the shadow must be dropped
- * by our caller.
+ * do a couple of quick checks to see if it's
+ * worthwhile grabbing the lock
*/
- if (((shadow_object = object->shadow) != VM_OBJECT_NULL) &&
- !(object->pageout)) {
- vm_object_lock(shadow_object);
- if (shadow_object->copy == object)
- shadow_object->copy = VM_OBJECT_NULL;
- vm_object_unlock(shadow_object);
+ if (queue_empty(&vm_object_cached_list)) {
+ KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, 0, 0, 0, 0, 0);
+ return (0);
}
+ clock_get_system_nanotime(&sec, &nsec);
- if (object->paging_in_progress != 0 ||
- object->activity_in_progress != 0) {
- /*
- * There are still some paging_in_progress references
- * on this object, meaning that there are some paging
- * or other I/O operations in progress for this VM object.
- * Such operations take some paging_in_progress references
- * up front to ensure that the object doesn't go away, but
- * they may also need to acquire a reference on the VM object,
- * to map it in kernel space, for example. That means that
- * they may end up releasing the last reference on the VM
- * object, triggering its termination, while still holding
- * paging_in_progress references. Waiting for these
- * pending paging_in_progress references to go away here would
- * deadlock.
- *
- * To avoid deadlocking, we'll let the vm_object_reaper_thread
- * complete the VM object termination if it still holds
- * paging_in_progress references at this point.
- *
- * No new paging_in_progress should appear now that the
- * VM object is "terminating" and not "alive".
- */
- vm_object_reap_async(object);
- vm_object_unlock(object);
- /*
- * Return KERN_FAILURE to let the caller know that we
- * haven't completed the termination and it can't drop this
- * object's reference on its shadow object yet.
- * The reaper thread will take care of that once it has
- * completed this object's termination.
- */
- return KERN_FAILURE;
- }
/*
- * complete the VM object termination
+ * the object on the head of the queue has not
+ * yet sufficiently aged
*/
- vm_object_reap(object);
- object = VM_OBJECT_NULL;
-
+ if (sec < vm_object_cache_aging_ts) {
+ KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, 0, 0, 0, 0, 0);
+ return (0);
+ }
/*
- * the object lock was released by vm_object_reap()
- *
- * KERN_SUCCESS means that this object has been terminated
- * and no longer needs its shadow object but still holds a
- * reference on it.
- * The caller is responsible for dropping that reference.
- * We can't call vm_object_deallocate() here because that
- * would create a recursion.
+ * don't need the queue lock to find
+ * and lock an object on the cached list
*/
- return KERN_SUCCESS;
-}
+ vm_page_unlock_queues();
+ vm_object_cache_lock_spin();
-/*
- * vm_object_reap():
- *
- * Complete the termination of a VM object after it's been marked
- * as "terminating" and "!alive" by vm_object_terminate().
- *
- * The VM object must be locked by caller.
- * The lock will be released on return and the VM object is no longer valid.
- */
-void
-vm_object_reap(
- vm_object_t object)
-{
- memory_object_t pager;
+ for (;;) {
+ next_obj = (vm_object_t)queue_first(&vm_object_cached_list);
- vm_object_lock_assert_exclusive(object);
- assert(object->paging_in_progress == 0);
- assert(object->activity_in_progress == 0);
+ while (!queue_end(&vm_object_cached_list, (queue_entry_t)next_obj) && object_cnt++ < max_objects_to_examine) {
- vm_object_reap_count++;
+ object = next_obj;
+ next_obj = (vm_object_t)queue_next(&next_obj->objq);
- pager = object->pager;
- object->pager = MEMORY_OBJECT_NULL;
+ assert(object->purgable == VM_PURGABLE_DENY);
+ assert(object->wired_page_count == 0);
+
+ if (sec < object->vo_cache_ts) {
+ KERNEL_DEBUG(0x130020c, object, object->resident_page_count, object->vo_cache_ts, sec, 0);
- if (pager != MEMORY_OBJECT_NULL)
- memory_object_control_disable(object->pager_control);
+ vm_object_cache_aging_ts = object->vo_cache_ts;
+ object = VM_OBJECT_NULL;
+ break;
+ }
+ if (!vm_object_lock_try_scan(object)) {
+ /*
+ * just skip over this guy for now... if we find
+ * an object to steal pages from, we'll revist in a bit...
+ * hopefully, the lock will have cleared
+ */
+ KERNEL_DEBUG(0x13001f8, object, object->resident_page_count, 0, 0, 0);
- object->ref_count--;
-#if TASK_SWAPPER
- assert(object->res_count == 0);
-#endif /* TASK_SWAPPER */
+ object = VM_OBJECT_NULL;
+ continue;
+ }
+ if (vm_page_queue_empty(&object->memq) || object->vo_cache_pages_to_scan == 0) {
+ /*
+ * this case really shouldn't happen, but it's not fatal
+ * so deal with it... if we don't remove the object from
+ * the list, we'll never move past it.
+ */
+ KERNEL_DEBUG(0x13001fc, object, object->resident_page_count, ep_freed, ep_moved, 0);
+
+ vm_object_cache_remove_locked(object);
+ vm_object_unlock(object);
+ object = VM_OBJECT_NULL;
+ continue;
+ }
+ /*
+ * we have a locked object with pages...
+ * time to start harvesting
+ */
+ break;
+ }
+ vm_object_cache_unlock();
- assert (object->ref_count == 0);
+ if (object == VM_OBJECT_NULL)
+ break;
- /*
- * remove from purgeable queue if it's on
- */
- if (object->objq.next || object->objq.prev) {
- purgeable_q_t queue = vm_purgeable_object_remove(object);
- assert(queue);
+ /*
+ * object is locked at this point and
+ * has resident pages
+ */
+ next_p = (vm_page_t)vm_page_queue_first(&object->memq);
- /* Must take page lock for this - using it to protect token queue */
- vm_page_lock_queues();
- vm_purgeable_token_delete_first(queue);
-
- assert(queue->debug_count_objects>=0);
- vm_page_unlock_queues();
- }
-
- /*
- * Clean or free the pages, as appropriate.
- * It is possible for us to find busy/absent pages,
- * if some faults on this object were aborted.
- */
- if (object->pageout) {
- assert(object->shadow != VM_OBJECT_NULL);
+ /*
+ * break the page scan into 2 pieces to minimize the time spent
+ * behind the page queue lock...
+ * the list of pages on these unused objects is likely to be cold
+ * w/r to the cpu cache which increases the time to scan the list
+ * tenfold... and we may have a 'run' of pages we can't utilize that
+ * needs to be skipped over...
+ */
+ if ((ep_limit = num_to_evict - (ep_freed + ep_moved)) > EVICT_PREPARE_LIMIT)
+ ep_limit = EVICT_PREPARE_LIMIT;
+ ep_count = 0;
- vm_pageout_object_terminate(object);
+ while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next_p) && object->vo_cache_pages_to_scan && ep_count < ep_limit) {
- } else if (((object->temporary && !object->can_persist) || (pager == MEMORY_OBJECT_NULL))) {
+ p = next_p;
+ next_p = (vm_page_t)vm_page_queue_next(&next_p->listq);
- vm_object_reap_pages(object, REAP_REAP);
- }
- assert(queue_empty(&object->memq));
- assert(object->paging_in_progress == 0);
- assert(object->activity_in_progress == 0);
- assert(object->ref_count == 0);
+ object->vo_cache_pages_to_scan--;
- /*
- * If the pager has not already been released by
- * vm_object_destroy, we need to terminate it and
- * release our reference to it here.
- */
- if (pager != MEMORY_OBJECT_NULL) {
- vm_object_unlock(object);
- vm_object_release_pager(pager, object->hashed);
- vm_object_lock(object);
- }
+ if (VM_PAGE_WIRED(p) || p->busy || p->cleaning || p->laundry) {
+ vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+ vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
- /* kick off anyone waiting on terminating */
- object->terminating = FALSE;
- vm_object_paging_begin(object);
- vm_object_paging_end(object);
- vm_object_unlock(object);
+ ep_skipped++;
+ continue;
+ }
+ if (p->wpmapped || p->dirty || p->precious) {
+ vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+ vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
-#if MACH_PAGEMAP
- vm_external_destroy(object->existence_map, object->size);
-#endif /* MACH_PAGEMAP */
+ pmap_clear_reference(VM_PAGE_GET_PHYS_PAGE(p));
+ }
+ ep_array[ep_count++] = p;
+ }
+ KERNEL_DEBUG(0x13001f4 | DBG_FUNC_START, object, object->resident_page_count, ep_freed, ep_moved, 0);
- object->shadow = VM_OBJECT_NULL;
+ vm_page_lockspin_queues();
- vm_object_lock_destroy(object);
- /*
- * Free the space for the object.
- */
- zfree(vm_object_zone, object);
- object = VM_OBJECT_NULL;
-}
+ for (ep_index = 0; ep_index < ep_count; ep_index++) {
+ p = ep_array[ep_index];
+ if (p->wpmapped || p->dirty || p->precious) {
+ p->reference = FALSE;
+ p->no_cache = FALSE;
-#define V_O_R_MAX_BATCH 128
+ /*
+ * we've already filtered out pages that are in the laundry
+ * so if we get here, this page can't be on the pageout queue
+ */
+ vm_page_queues_remove(p, FALSE);
+ vm_page_enqueue_inactive(p, TRUE);
+ ep_moved++;
+ } else {
+#if CONFIG_PHANTOM_CACHE
+ vm_phantom_cache_add_ghost(p);
+#endif
+ vm_page_free_prepare_queues(p);
-#define VM_OBJ_REAP_FREELIST(_local_free_q, do_disconnect) \
- MACRO_BEGIN \
- if (_local_free_q) { \
- if (do_disconnect) { \
- vm_page_t m; \
- for (m = _local_free_q; \
- m != VM_PAGE_NULL; \
- m = (vm_page_t) m->pageq.next) { \
- if (m->pmapped) { \
- pmap_disconnect(m->phys_page); \
- } \
- } \
- } \
- vm_page_free_list(_local_free_q, TRUE); \
- _local_free_q = VM_PAGE_NULL; \
- } \
- MACRO_END
+ assert(p->pageq.next == 0 && p->pageq.prev == 0);
+ /*
+ * Add this page to our list of reclaimed pages,
+ * to be freed later.
+ */
+ p->snext = local_free_q;
+ local_free_q = p;
+ ep_freed++;
+ }
+ }
+ vm_page_unlock_queues();
-void
-vm_object_reap_pages(
- vm_object_t object,
- int reap_type)
-{
- vm_page_t p;
- vm_page_t next;
- vm_page_t local_free_q = VM_PAGE_NULL;
- int loop_count;
- boolean_t disconnect_on_release;
+ KERNEL_DEBUG(0x13001f4 | DBG_FUNC_END, object, object->resident_page_count, ep_freed, ep_moved, 0);
- if (reap_type == REAP_DATA_FLUSH) {
+ if (local_free_q) {
+ vm_page_free_list(local_free_q, TRUE);
+ local_free_q = VM_PAGE_NULL;
+ }
+ if (object->vo_cache_pages_to_scan == 0) {
+ KERNEL_DEBUG(0x1300208, object, object->resident_page_count, ep_freed, ep_moved, 0);
+
+ vm_object_cache_remove(object);
+
+ KERNEL_DEBUG(0x13001fc, object, object->resident_page_count, ep_freed, ep_moved, 0);
+ }
/*
- * We need to disconnect pages from all pmaps before
- * releasing them to the free list
+ * done with this object
*/
- disconnect_on_release = TRUE;
- } else {
+ vm_object_unlock(object);
+ object = VM_OBJECT_NULL;
+
/*
- * Either the caller has already disconnected the pages
- * from all pmaps, or we disconnect them here as we add
- * them to out local list of pages to be released.
- * No need to re-disconnect them when we release the pages
- * to the free list.
+ * at this point, we are not holding any locks
*/
- disconnect_on_release = FALSE;
+ if ((ep_freed + ep_moved) >= num_to_evict) {
+ /*
+ * we've reached our target for the
+ * number of pages to evict
+ */
+ break;
+ }
+ vm_object_cache_lock_spin();
}
-
-restart_after_sleep:
- if (queue_empty(&object->memq))
- return;
- loop_count = V_O_R_MAX_BATCH + 1;
-
- vm_page_lockspin_queues();
+ /*
+ * put the page queues lock back to the caller's
+ * idea of it
+ */
+ vm_page_lock_queues();
- next = (vm_page_t)queue_first(&object->memq);
+ vm_object_cache_pages_freed += ep_freed;
+ vm_object_cache_pages_moved += ep_moved;
+ vm_object_cache_pages_skipped += ep_skipped;
- while (!queue_end(&object->memq, (queue_entry_t)next)) {
+ KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, ep_freed, 0, 0, 0, 0);
+ return (ep_freed);
+}
- p = next;
- next = (vm_page_t)queue_next(&next->listq);
- if (--loop_count == 0) {
-
- vm_page_unlock_queues();
+#if VM_OBJECT_CACHE
+/*
+ * Check to see whether we really need to trim
+ * down the cache. If so, remove an object from
+ * the cache, terminate it, and repeat.
+ *
+ * Called with, and returns with, cache lock unlocked.
+ */
+vm_object_t
+vm_object_cache_trim(
+ boolean_t called_from_vm_object_deallocate)
+{
+ vm_object_t object = VM_OBJECT_NULL;
+ vm_object_t shadow;
- if (local_free_q) {
- /*
- * Free the pages we reclaimed so far
- * and take a little break to avoid
- * hogging the page queue lock too long
- */
- VM_OBJ_REAP_FREELIST(local_free_q,
- disconnect_on_release);
- } else
- mutex_pause(0);
+ for (;;) {
- loop_count = V_O_R_MAX_BATCH + 1;
+ /*
+ * If we no longer need to trim the cache,
+ * then we are done.
+ */
+ if (vm_object_cached_count <= vm_object_cached_max)
+ return VM_OBJECT_NULL;
- vm_page_lockspin_queues();
+ vm_object_cache_lock();
+ if (vm_object_cached_count <= vm_object_cached_max) {
+ vm_object_cache_unlock();
+ return VM_OBJECT_NULL;
}
- if (reap_type == REAP_DATA_FLUSH || reap_type == REAP_TERMINATE) {
-
- if (reap_type == REAP_DATA_FLUSH && (p->pageout == TRUE && p->list_req_pending == TRUE)) {
- p->list_req_pending = FALSE;
- p->cleaning = FALSE;
- p->pageout = FALSE;
- /*
- * need to drop the laundry count...
- * we may also need to remove it
- * from the I/O paging queue...
- * vm_pageout_throttle_up handles both cases
- *
- * the laundry and pageout_queue flags are cleared...
- */
- vm_pageout_throttle_up(p);
-
- /*
- * toss the wire count we picked up
- * when we intially set this page up
- * to be cleaned...
- */
- vm_page_unwire(p);
- PAGE_WAKEUP(p);
-
- } else if (p->busy || p->cleaning) {
-
- vm_page_unlock_queues();
- /*
- * free the pages reclaimed so far
- */
- VM_OBJ_REAP_FREELIST(local_free_q,
- disconnect_on_release);
- PAGE_SLEEP(object, p, THREAD_UNINT);
+ /*
+ * We must trim down the cache, so remove
+ * the first object in the cache.
+ */
+ XPR(XPR_VM_OBJECT,
+ "vm_object_cache_trim: removing from front of cache (%x, %x)\n",
+ vm_object_cached_list.next,
+ vm_object_cached_list.prev, 0, 0, 0);
- goto restart_after_sleep;
- }
+ object = (vm_object_t) queue_first(&vm_object_cached_list);
+ if(object == (vm_object_t) &vm_object_cached_list) {
+ /* something's wrong with the calling parameter or */
+ /* the value of vm_object_cached_count, just fix */
+ /* and return */
+ if(vm_object_cached_max < 0)
+ vm_object_cached_max = 0;
+ vm_object_cached_count = 0;
+ vm_object_cache_unlock();
+ return VM_OBJECT_NULL;
}
- switch (reap_type) {
-
- case REAP_DATA_FLUSH:
- if (VM_PAGE_WIRED(p)) {
- /*
- * this is an odd case... perhaps we should
- * zero-fill this page since we're conceptually
- * tossing its data at this point, but leaving
- * it on the object to honor the 'wire' contract
- */
- continue;
- }
- break;
-
- case REAP_PURGEABLE:
- if (VM_PAGE_WIRED(p)) {
- /* can't purge a wired page */
- vm_page_purged_wired++;
- continue;
- }
-
- if (p->busy) {
- /*
- * We can't reclaim a busy page but we can
- * make it pageable (it's not wired) to make
- * sure that it gets considered by
- * vm_pageout_scan() later.
- */
- vm_page_deactivate(p);
- vm_page_purged_busy++;
- continue;
- }
-
- if (p->cleaning || p->laundry || p->list_req_pending) {
- /*
- * page is being acted upon,
- * so don't mess with it
- */
- vm_page_purged_others++;
- continue;
- }
- assert(p->object != kernel_object);
-
- /*
- * we can discard this page...
- */
- if (p->pmapped == TRUE) {
- int refmod_state;
- /*
- * unmap the page
- */
- refmod_state = pmap_disconnect(p->phys_page);
- if (refmod_state & VM_MEM_MODIFIED) {
- p->dirty = TRUE;
- }
- }
- if (p->dirty || p->precious) {
- /*
- * we saved the cost of cleaning this page !
- */
- vm_page_purged_count++;
- }
-
- break;
-
- case REAP_TERMINATE:
- if (p->absent || p->private) {
- /*
- * For private pages, VM_PAGE_FREE just
- * leaves the page structure around for
- * its owner to clean up. For absent
- * pages, the structure is returned to
- * the appropriate pool.
- */
- break;
- }
- if (p->fictitious) {
- assert (p->phys_page == vm_page_guard_addr);
- break;
- }
- if (!p->dirty && p->wpmapped)
- p->dirty = pmap_is_modified(p->phys_page);
-
- if ((p->dirty || p->precious) && !p->error && object->alive) {
+ vm_object_lock(object);
+ queue_remove(&vm_object_cached_list, object, vm_object_t,
+ cached_list);
+ vm_object_cached_count--;
- p->busy = TRUE;
+ vm_object_cache_unlock();
+ /*
+ * Since this object is in the cache, we know
+ * that it is initialized and has no references.
+ * Take a reference to avoid recursive deallocations.
+ */
- VM_PAGE_QUEUES_REMOVE(p);
+ assert(object->pager_initialized);
+ assert(object->ref_count == 0);
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count++;
- vm_page_unlock_queues();
- /*
- * free the pages reclaimed so far
- */
- VM_OBJ_REAP_FREELIST(local_free_q,
- disconnect_on_release);
+ /*
+ * Terminate the object.
+ * If the object had a shadow, we let vm_object_deallocate
+ * deallocate it. "pageout" objects have a shadow, but
+ * maintain a "paging reference" rather than a normal
+ * reference.
+ * (We are careful here to limit recursion.)
+ */
+ shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
- /*
- * flush page... page will be freed
- * upon completion of I/O
- */
- vm_pageout_cluster(p);
- vm_object_paging_wait(object, THREAD_UNINT);
+ if(vm_object_terminate(object) != KERN_SUCCESS)
+ continue;
- goto restart_after_sleep;
+ if (shadow != VM_OBJECT_NULL) {
+ if (called_from_vm_object_deallocate) {
+ return shadow;
+ } else {
+ vm_object_deallocate(shadow);
}
- break;
-
- case REAP_REAP:
- break;
}
- vm_page_free_prepare_queues(p);
- assert(p->pageq.next == NULL && p->pageq.prev == NULL);
- /*
- * Add this page to our list of reclaimed pages,
- * to be freed later.
- */
- p->pageq.next = (queue_entry_t) local_free_q;
- local_free_q = p;
}
- vm_page_unlock_queues();
-
- /*
- * Free the remaining reclaimed pages
- */
- VM_OBJ_REAP_FREELIST(local_free_q,
- disconnect_on_release);
}
+#endif
-void
-vm_object_reap_async(
+/*
+ * Routine: vm_object_terminate
+ * Purpose:
+ * Free all resources associated with a vm_object.
+ * In/out conditions:
+ * Upon entry, the object must be locked,
+ * and the object must have exactly one reference.
+ *
+ * The shadow object reference is left alone.
+ *
+ * The object must be unlocked if its found that pages
+ * must be flushed to a backing object. If someone
+ * manages to map the object while it is being flushed
+ * the object is returned unlocked and unchanged. Otherwise,
+ * upon exit, the cache will be unlocked, and the
+ * object will cease to exist.
+ */
+static kern_return_t
+vm_object_terminate(
vm_object_t object)
{
- vm_object_lock_assert_exclusive(object);
-
- vm_object_reaper_lock_spin();
-
- vm_object_reap_count_async++;
+ vm_object_t shadow_object;
- /* enqueue the VM object... */
- queue_enter(&vm_object_reaper_queue, object,
- vm_object_t, cached_list);
+ XPR(XPR_VM_OBJECT, "vm_object_terminate, object 0x%X ref %d\n",
+ object, object->ref_count, 0, 0, 0);
- vm_object_reaper_unlock();
+ vm_object_lock_assert_exclusive(object);
- /* ... and wake up the reaper thread */
- thread_wakeup((event_t) &vm_object_reaper_queue);
-}
+ if (!object->pageout && (!object->temporary || object->can_persist) &&
+ (object->pager != NULL || object->shadow_severed)) {
+ /*
+ * Clear pager_trusted bit so that the pages get yanked
+ * out of the object instead of cleaned in place. This
+ * prevents a deadlock in XMM and makes more sense anyway.
+ */
+ object->pager_trusted = FALSE;
-
-void
-vm_object_reaper_thread(void)
-{
- vm_object_t object, shadow_object;
-
- vm_object_reaper_lock_spin();
-
- while (!queue_empty(&vm_object_reaper_queue)) {
- queue_remove_first(&vm_object_reaper_queue,
- object,
- vm_object_t,
- cached_list);
-
- vm_object_reaper_unlock();
- vm_object_lock(object);
-
- assert(object->terminating);
- assert(!object->alive);
-
- /*
- * The pageout daemon might be playing with our pages.
- * Now that the object is dead, it won't touch any more
- * pages, but some pages might already be on their way out.
- * Hence, we wait until the active paging activities have
- * ceased before we break the association with the pager
- * itself.
- */
- while (object->paging_in_progress != 0 ||
- object->activity_in_progress != 0) {
- vm_object_wait(object,
- VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
- THREAD_UNINT);
- vm_object_lock(object);
- }
-
- shadow_object =
- object->pageout ? VM_OBJECT_NULL : object->shadow;
-
- vm_object_reap(object);
- /* cache is unlocked and object is no longer valid */
- object = VM_OBJECT_NULL;
-
- if (shadow_object != VM_OBJECT_NULL) {
- /*
- * Drop the reference "object" was holding on
- * its shadow object.
- */
- vm_object_deallocate(shadow_object);
- shadow_object = VM_OBJECT_NULL;
- }
- vm_object_reaper_lock_spin();
+ vm_object_reap_pages(object, REAP_TERMINATE);
}
-
- /* wait for more work... */
- assert_wait((event_t) &vm_object_reaper_queue, THREAD_UNINT);
-
- vm_object_reaper_unlock();
-
- thread_block((thread_continue_t) vm_object_reaper_thread);
- /*NOTREACHED*/
-}
-
-/*
- * Routine: vm_object_pager_wakeup
- * Purpose: Wake up anyone waiting for termination of a pager.
- */
-
-static void
-vm_object_pager_wakeup(
- memory_object_t pager)
-{
- vm_object_hash_entry_t entry;
- boolean_t waiting = FALSE;
- lck_mtx_t *lck;
-
/*
- * If anyone was waiting for the memory_object_terminate
- * to be queued, wake them up now.
+ * Make sure the object isn't already being terminated
*/
- lck = vm_object_hash_lock_spin(pager);
- entry = vm_object_hash_lookup(pager, TRUE);
- if (entry != VM_OBJECT_HASH_ENTRY_NULL)
- waiting = entry->waiting;
- vm_object_hash_unlock(lck);
-
- if (entry != VM_OBJECT_HASH_ENTRY_NULL) {
- if (waiting)
- thread_wakeup((event_t) pager);
- vm_object_hash_entry_free(entry);
+ if (object->terminating) {
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count--;
+ assert(object->ref_count > 0);
+ vm_object_unlock(object);
+ return KERN_FAILURE;
}
-}
-
-/*
- * Routine: vm_object_release_pager
- * Purpose: Terminate the pager and, upon completion,
- * release our last reference to it.
- * just like memory_object_terminate, except
- * that we wake up anyone blocked in vm_object_enter
- * waiting for termination message to be queued
- * before calling memory_object_init.
- */
-static void
-vm_object_release_pager(
- memory_object_t pager,
- boolean_t hashed)
-{
/*
- * Terminate the pager.
+ * Did somebody get a reference to the object while we were
+ * cleaning it?
*/
-
- (void) memory_object_terminate(pager);
-
- if (hashed == TRUE) {
- /*
- * Wakeup anyone waiting for this terminate
- * and remove the entry from the hash
- */
- vm_object_pager_wakeup(pager);
+ if (object->ref_count != 1) {
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count--;
+ assert(object->ref_count > 0);
+ vm_object_res_deallocate(object);
+ vm_object_unlock(object);
+ return KERN_FAILURE;
}
- /*
- * Release reference to pager.
- */
- memory_object_deallocate(pager);
-}
-
-/*
- * Routine: vm_object_destroy
- * Purpose:
- * Shut down a VM object, despite the
- * presence of address map (or other) references
- * to the vm_object.
- */
-kern_return_t
-vm_object_destroy(
- vm_object_t object,
- __unused kern_return_t reason)
-{
- memory_object_t old_pager;
-
- if (object == VM_OBJECT_NULL)
- return(KERN_SUCCESS);
/*
- * Remove the pager association immediately.
- *
- * This will prevent the memory manager from further
- * meddling. [If it wanted to flush data or make
- * other changes, it should have done so before performing
- * the destroy call.]
+ * Make sure no one can look us up now.
*/
- vm_object_lock(object);
- object->can_persist = FALSE;
- object->named = FALSE;
+ object->terminating = TRUE;
object->alive = FALSE;
+ if ( !object->internal && (object->objq.next || object->objq.prev))
+ vm_object_cache_remove(object);
+
if (object->hashed) {
lck_mtx_t *lck;
- /*
- * Rip out the pager from the vm_object now...
- */
+
lck = vm_object_hash_lock_spin(object->pager);
vm_object_remove(object);
vm_object_hash_unlock(lck);
}
- old_pager = object->pager;
- object->pager = MEMORY_OBJECT_NULL;
- if (old_pager != MEMORY_OBJECT_NULL)
- memory_object_control_disable(object->pager_control);
-
/*
- * Wait for the existing paging activity (that got
- * through before we nulled out the pager) to subside.
+ * Detach the object from its shadow if we are the shadow's
+ * copy. The reference we hold on the shadow must be dropped
+ * by our caller.
*/
+ if (((shadow_object = object->shadow) != VM_OBJECT_NULL) &&
+ !(object->pageout)) {
+ vm_object_lock(shadow_object);
+ if (shadow_object->copy == object)
+ shadow_object->copy = VM_OBJECT_NULL;
+ vm_object_unlock(shadow_object);
+ }
- vm_object_paging_wait(object, THREAD_UNINT);
- vm_object_unlock(object);
-
+ if (object->paging_in_progress != 0 ||
+ object->activity_in_progress != 0) {
+ /*
+ * There are still some paging_in_progress references
+ * on this object, meaning that there are some paging
+ * or other I/O operations in progress for this VM object.
+ * Such operations take some paging_in_progress references
+ * up front to ensure that the object doesn't go away, but
+ * they may also need to acquire a reference on the VM object,
+ * to map it in kernel space, for example. That means that
+ * they may end up releasing the last reference on the VM
+ * object, triggering its termination, while still holding
+ * paging_in_progress references. Waiting for these
+ * pending paging_in_progress references to go away here would
+ * deadlock.
+ *
+ * To avoid deadlocking, we'll let the vm_object_reaper_thread
+ * complete the VM object termination if it still holds
+ * paging_in_progress references at this point.
+ *
+ * No new paging_in_progress should appear now that the
+ * VM object is "terminating" and not "alive".
+ */
+ vm_object_reap_async(object);
+ vm_object_unlock(object);
+ /*
+ * Return KERN_FAILURE to let the caller know that we
+ * haven't completed the termination and it can't drop this
+ * object's reference on its shadow object yet.
+ * The reaper thread will take care of that once it has
+ * completed this object's termination.
+ */
+ return KERN_FAILURE;
+ }
/*
- * Terminate the object now.
+ * complete the VM object termination
*/
- if (old_pager != MEMORY_OBJECT_NULL) {
- vm_object_release_pager(old_pager, object->hashed);
-
- /*
- * JMM - Release the caller's reference. This assumes the
- * caller had a reference to release, which is a big (but
- * currently valid) assumption if this is driven from the
- * vnode pager (it is holding a named reference when making
- * this call)..
- */
- vm_object_deallocate(object);
+ vm_object_reap(object);
+ object = VM_OBJECT_NULL;
- }
- return(KERN_SUCCESS);
+ /*
+ * the object lock was released by vm_object_reap()
+ *
+ * KERN_SUCCESS means that this object has been terminated
+ * and no longer needs its shadow object but still holds a
+ * reference on it.
+ * The caller is responsible for dropping that reference.
+ * We can't call vm_object_deallocate() here because that
+ * would create a recursion.
+ */
+ return KERN_SUCCESS;
}
-#define VM_OBJ_DEACT_ALL_STATS DEBUG
-#if VM_OBJ_DEACT_ALL_STATS
-uint32_t vm_object_deactivate_all_pages_batches = 0;
-uint32_t vm_object_deactivate_all_pages_pages = 0;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
/*
- * vm_object_deactivate_all_pages
+ * vm_object_reap():
*
- * Deactivate all pages in the specified object. (Keep its pages
- * in memory even though it is no longer referenced.)
+ * Complete the termination of a VM object after it's been marked
+ * as "terminating" and "!alive" by vm_object_terminate().
*
- * The object must be locked.
+ * The VM object must be locked by caller.
+ * The lock will be released on return and the VM object is no longer valid.
*/
-static void
-vm_object_deactivate_all_pages(
- register vm_object_t object)
-{
- register vm_page_t p;
- int loop_count;
-#if VM_OBJ_DEACT_ALL_STATS
- int pages_count;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
-#define V_O_D_A_P_MAX_BATCH 256
-
- loop_count = V_O_D_A_P_MAX_BATCH;
-#if VM_OBJ_DEACT_ALL_STATS
- pages_count = 0;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
- vm_page_lock_queues();
- queue_iterate(&object->memq, p, vm_page_t, listq) {
- if (--loop_count == 0) {
-#if VM_OBJ_DEACT_ALL_STATS
- hw_atomic_add(&vm_object_deactivate_all_pages_batches,
- 1);
- hw_atomic_add(&vm_object_deactivate_all_pages_pages,
- pages_count);
- pages_count = 0;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
- lck_mtx_yield(&vm_page_queue_lock);
- loop_count = V_O_D_A_P_MAX_BATCH;
- }
- if (!p->busy && !p->throttled) {
-#if VM_OBJ_DEACT_ALL_STATS
- pages_count++;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
- vm_page_deactivate(p);
- }
- }
-#if VM_OBJ_DEACT_ALL_STATS
- if (pages_count) {
- hw_atomic_add(&vm_object_deactivate_all_pages_batches, 1);
- hw_atomic_add(&vm_object_deactivate_all_pages_pages,
- pages_count);
- pages_count = 0;
- }
-#endif /* VM_OBJ_DEACT_ALL_STATS */
- vm_page_unlock_queues();
-}
-
+void
+vm_object_reap(
+ vm_object_t object)
+{
+ memory_object_t pager;
-/*
- * when deallocating pages it is necessary to hold
- * the vm_page_queue_lock (a hot global lock) for certain operations
- * on the page... however, the majority of the work can be done
- * while merely holding the object lock... to mitigate the time spent behind the
- * global lock, go to a 2 pass algorithm... collect pages up to DELAYED_WORK_LIMIT
- * while doing all of the work that doesn't require the vm_page_queue_lock...
- * them call dw_do_work to acquire the vm_page_queue_lock and do the
- * necessary work for each page... we will grab the busy bit on the page
- * so that dw_do_work can drop the object lock if it can't immediately take the
- * vm_page_queue_lock in order to compete for the locks in the same order that
- * vm_pageout_scan takes them.
- */
-
-#define DELAYED_WORK_LIMIT 32
+ vm_object_lock_assert_exclusive(object);
+ assert(object->paging_in_progress == 0);
+ assert(object->activity_in_progress == 0);
-#define DW_clear_reference 0x01
-#define DW_move_page 0x02
-#define DW_clear_busy 0x04
-#define DW_PAGE_WAKEUP 0x08
+ vm_object_reap_count++;
+ /*
+ * Disown this purgeable object to cleanup its owner's purgeable
+ * ledgers. We need to do this before disconnecting the object
+ * from its pager, to properly account for compressed pages.
+ */
+ if (object->internal &&
+ object->purgable != VM_PURGABLE_DENY) {
+ vm_purgeable_accounting(object,
+ object->purgable,
+ TRUE); /* disown */
+ }
-struct dw {
- vm_page_t dw_m;
- int dw_mask;
-};
+ pager = object->pager;
+ object->pager = MEMORY_OBJECT_NULL;
-static void dw_do_work(vm_object_t object, struct dw *dwp, int dw_count);
+ if (pager != MEMORY_OBJECT_NULL)
+ memory_object_control_disable(object->pager_control);
+ object->ref_count--;
+#if TASK_SWAPPER
+ assert(object->res_count == 0);
+#endif /* TASK_SWAPPER */
-static void
-dw_do_work(
- vm_object_t object,
- struct dw *dwp,
- int dw_count)
-{
- vm_page_t m;
- int j;
+ assert (object->ref_count == 0);
/*
- * pageout_scan takes the vm_page_lock_queues first
- * then tries for the object lock... to avoid what
- * is effectively a lock inversion, we'll go to the
- * trouble of taking them in that same order... otherwise
- * if this object contains the majority of the pages resident
- * in the UBC (or a small set of large objects actively being
- * worked on contain the majority of the pages), we could
- * cause the pageout_scan thread to 'starve' in its attempt
- * to find pages to move to the free queue, since it has to
- * successfully acquire the object lock of any candidate page
- * before it can steal/clean it.
+ * remove from purgeable queue if it's on
*/
- if (!vm_page_trylockspin_queues()) {
- vm_object_unlock(object);
+ if (object->internal) {
+ task_t owner;
- vm_page_lockspin_queues();
+ owner = object->vo_purgeable_owner;
- for (j = 0; ; j++) {
- if (!vm_object_lock_avoid(object) &&
- _vm_object_lock_try(object))
- break;
- vm_page_unlock_queues();
- mutex_pause(j);
- vm_page_lockspin_queues();
- }
- }
- for (j = 0; j < dw_count; j++, dwp++) {
+ VM_OBJECT_UNWIRED(object);
- m = dwp->dw_m;
+ if (object->purgable == VM_PURGABLE_DENY) {
+ /* not purgeable: nothing to do */
+ } else if (object->purgable == VM_PURGABLE_VOLATILE) {
+ purgeable_q_t queue;
- if (dwp->dw_mask & DW_clear_reference)
- m->reference = FALSE;
+ assert(object->vo_purgeable_owner == NULL);
- if (dwp->dw_mask & DW_move_page) {
- VM_PAGE_QUEUES_REMOVE(m);
+ queue = vm_purgeable_object_remove(object);
+ assert(queue);
- assert(!m->laundry);
- assert(m->object != kernel_object);
- assert(m->pageq.next == NULL &&
- m->pageq.prev == NULL);
-
- if (m->zero_fill) {
- queue_enter_first(&vm_page_queue_zf, m, vm_page_t, pageq);
- vm_zf_queue_count++;
- } else {
- queue_enter_first(&vm_page_queue_inactive, m, vm_page_t, pageq);
+ if (object->purgeable_when_ripe) {
+ /*
+ * Must take page lock for this -
+ * using it to protect token queue
+ */
+ vm_page_lock_queues();
+ vm_purgeable_token_delete_first(queue);
+
+ assert(queue->debug_count_objects>=0);
+ vm_page_unlock_queues();
}
- m->inactive = TRUE;
- if (!m->fictitious) {
- vm_page_inactive_count++;
- token_new_pagecount++;
- } else {
- assert(m->phys_page == vm_page_fictitious_addr);
+ /*
+ * Update "vm_page_purgeable_count" in bulk and mark
+ * object as VM_PURGABLE_EMPTY to avoid updating
+ * "vm_page_purgeable_count" again in vm_page_remove()
+ * when reaping the pages.
+ */
+ unsigned int delta;
+ assert(object->resident_page_count >=
+ object->wired_page_count);
+ delta = (object->resident_page_count -
+ object->wired_page_count);
+ if (delta != 0) {
+ assert(vm_page_purgeable_count >= delta);
+ OSAddAtomic(-delta,
+ (SInt32 *)&vm_page_purgeable_count);
}
+ if (object->wired_page_count != 0) {
+ assert(vm_page_purgeable_wired_count >=
+ object->wired_page_count);
+ OSAddAtomic(-object->wired_page_count,
+ (SInt32 *)&vm_page_purgeable_wired_count);
+ }
+ object->purgable = VM_PURGABLE_EMPTY;
}
- if (dwp->dw_mask & DW_clear_busy)
- dwp->dw_m->busy = FALSE;
-
- if (dwp->dw_mask & DW_PAGE_WAKEUP)
- PAGE_WAKEUP(dwp->dw_m);
+ else if (object->purgable == VM_PURGABLE_NONVOLATILE ||
+ object->purgable == VM_PURGABLE_EMPTY) {
+ /* remove from nonvolatile queue */
+ assert(object->vo_purgeable_owner == TASK_NULL);
+ vm_purgeable_nonvolatile_dequeue(object);
+ } else {
+ panic("object %p in unexpected purgeable state 0x%x\n",
+ object, object->purgable);
+ }
+ assert(object->objq.next == NULL);
+ assert(object->objq.prev == NULL);
}
- vm_page_unlock_queues();
+
+ /*
+ * Clean or free the pages, as appropriate.
+ * It is possible for us to find busy/absent pages,
+ * if some faults on this object were aborted.
+ */
+ if (object->pageout) {
+ assert(object->shadow != VM_OBJECT_NULL);
-#if CONFIG_EMBEDDED
- {
- int percent_avail;
+ vm_pageout_object_terminate(object);
+
+ } else if (((object->temporary && !object->can_persist) || (pager == MEMORY_OBJECT_NULL))) {
+
+ vm_object_reap_pages(object, REAP_REAP);
+ }
+ assert(vm_page_queue_empty(&object->memq));
+ assert(object->paging_in_progress == 0);
+ assert(object->activity_in_progress == 0);
+ assert(object->ref_count == 0);
/*
- * Decide if we need to send a memory status notification.
+ * If the pager has not already been released by
+ * vm_object_destroy, we need to terminate it and
+ * release our reference to it here.
*/
- percent_avail =
- (vm_page_active_count + vm_page_inactive_count +
- vm_page_speculative_count + vm_page_free_count +
- (IP_VALID(memory_manager_default)?0:vm_page_purgeable_count) ) * 100 /
- atop_64(max_mem);
- if (percent_avail >= (kern_memorystatus_level + 5) ||
- percent_avail <= (kern_memorystatus_level - 5)) {
- kern_memorystatus_level = percent_avail;
- thread_wakeup((event_t)&kern_memorystatus_wakeup);
- }
+ if (pager != MEMORY_OBJECT_NULL) {
+ vm_object_unlock(object);
+ vm_object_release_pager(pager, object->hashed);
+ vm_object_lock(object);
}
-#endif
-}
+ /* kick off anyone waiting on terminating */
+ object->terminating = FALSE;
+ vm_object_paging_begin(object);
+ vm_object_paging_end(object);
+ vm_object_unlock(object);
+ object->shadow = VM_OBJECT_NULL;
-/*
- * The "chunk" macros are used by routines below when looking for pages to deactivate. These
- * exist because of the need to handle shadow chains. When deactivating pages, we only
- * want to deactive the ones at the top most level in the object chain. In order to do
- * this efficiently, the specified address range is divided up into "chunks" and we use
- * a bit map to keep track of which pages have already been processed as we descend down
- * the shadow chain. These chunk macros hide the details of the bit map implementation
- * as much as we can.
- *
- * For convenience, we use a 64-bit data type as the bit map, and therefore a chunk is
- * set to 64 pages. The bit map is indexed from the low-order end, so that the lowest
- * order bit represents page 0 in the current range and highest order bit represents
- * page 63.
- *
- * For further convenience, we also use negative logic for the page state in the bit map.
- * The bit is set to 1 to indicate it has not yet been seen, and to 0 to indicate it has
- * been processed. This way we can simply test the 64-bit long word to see if it's zero
- * to easily tell if the whole range has been processed. Therefore, the bit map starts
- * out with all the bits set. The macros below hide all these details from the caller.
- */
+#if VM_OBJECT_TRACKING
+ if (vm_object_tracking_inited) {
+ btlog_remove_entries_for_element(vm_object_tracking_btlog,
+ object);
+ }
+#endif /* VM_OBJECT_TRACKING */
-#define PAGES_IN_A_CHUNK 64 /* The number of pages in the chunk must */
- /* be the same as the number of bits in */
- /* the chunk_state_t type. We use 64 */
- /* just for convenience. */
+ vm_object_lock_destroy(object);
+ /*
+ * Free the space for the object.
+ */
+ zfree(vm_object_zone, object);
+ object = VM_OBJECT_NULL;
+}
-#define CHUNK_SIZE (PAGES_IN_A_CHUNK * PAGE_SIZE_64) /* Size of a chunk in bytes */
-typedef uint64_t chunk_state_t;
+unsigned int vm_max_batch = 256;
-/*
- * The bit map uses negative logic, so we start out with all 64 bits set to indicate
- * that no pages have been processed yet. Also, if len is less than the full CHUNK_SIZE,
- * then we mark pages beyond the len as having been "processed" so that we don't waste time
- * looking at pages in that range. This can save us from unnecessarily chasing down the
- * shadow chain.
- */
+#define V_O_R_MAX_BATCH 128
-#define CHUNK_INIT(c, len) \
+#define BATCH_LIMIT(max) (vm_max_batch >= max ? max : vm_max_batch)
+
+
+#define VM_OBJ_REAP_FREELIST(_local_free_q, do_disconnect) \
MACRO_BEGIN \
- uint64_t p; \
- \
- (c) = 0xffffffffffffffffLL; \
- \
- for (p = (len) / PAGE_SIZE_64; p < PAGES_IN_A_CHUNK; p++) \
- MARK_PAGE_HANDLED(c, p); \
+ if (_local_free_q) { \
+ if (do_disconnect) { \
+ vm_page_t m; \
+ for (m = _local_free_q; \
+ m != VM_PAGE_NULL; \
+ m = m->snext) { \
+ if (m->pmapped) { \
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m)); \
+ } \
+ } \
+ } \
+ vm_page_free_list(_local_free_q, TRUE); \
+ _local_free_q = VM_PAGE_NULL; \
+ } \
MACRO_END
-/*
- * Return true if all pages in the chunk have not yet been processed.
- */
-#define CHUNK_NOT_COMPLETE(c) ((c) != 0)
+void
+vm_object_reap_pages(
+ vm_object_t object,
+ int reap_type)
+{
+ vm_page_t p;
+ vm_page_t next;
+ vm_page_t local_free_q = VM_PAGE_NULL;
+ int loop_count;
+ boolean_t disconnect_on_release;
+ pmap_flush_context pmap_flush_context_storage;
-/*
- * Return true if the page at offset 'p' in the bit map has already been handled
- * while processing a higher level object in the shadow chain.
- */
+ if (reap_type == REAP_DATA_FLUSH) {
+ /*
+ * We need to disconnect pages from all pmaps before
+ * releasing them to the free list
+ */
+ disconnect_on_release = TRUE;
+ } else {
+ /*
+ * Either the caller has already disconnected the pages
+ * from all pmaps, or we disconnect them here as we add
+ * them to out local list of pages to be released.
+ * No need to re-disconnect them when we release the pages
+ * to the free list.
+ */
+ disconnect_on_release = FALSE;
+ }
+
+restart_after_sleep:
+ if (vm_page_queue_empty(&object->memq))
+ return;
+ loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH);
-#define PAGE_ALREADY_HANDLED(c, p) (((c) & (1LL << (p))) == 0)
+ if (reap_type == REAP_PURGEABLE)
+ pmap_flush_context_init(&pmap_flush_context_storage);
-/*
- * Mark the page at offset 'p' in the bit map as having been processed.
- */
+ vm_page_lockspin_queues();
-#define MARK_PAGE_HANDLED(c, p) \
-MACRO_BEGIN \
- (c) = (c) & ~(1LL << (p)); \
-MACRO_END
+ next = (vm_page_t)vm_page_queue_first(&object->memq);
+ while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next)) {
-/*
- * Return true if the page at the given offset has been paged out. Object is
- * locked upon entry and returned locked.
- */
+ p = next;
+ next = (vm_page_t)vm_page_queue_next(&next->listq);
-static boolean_t
-page_is_paged_out(
- vm_object_t object,
- vm_object_offset_t offset)
-{
- kern_return_t kr;
- memory_object_t pager;
+ if (--loop_count == 0) {
+
+ vm_page_unlock_queues();
- /*
- * Check the existence map for the page if we have one, otherwise
- * ask the pager about this page.
- */
+ if (local_free_q) {
-#if MACH_PAGEMAP
- if (object->existence_map) {
- if (vm_external_state_get(object->existence_map, offset)
- == VM_EXTERNAL_STATE_EXISTS) {
- /*
- * We found the page
- */
+ if (reap_type == REAP_PURGEABLE) {
+ pmap_flush(&pmap_flush_context_storage);
+ pmap_flush_context_init(&pmap_flush_context_storage);
+ }
+ /*
+ * Free the pages we reclaimed so far
+ * and take a little break to avoid
+ * hogging the page queue lock too long
+ */
+ VM_OBJ_REAP_FREELIST(local_free_q,
+ disconnect_on_release);
+ } else
+ mutex_pause(0);
- return TRUE;
+ loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH);
+
+ vm_page_lockspin_queues();
}
- } else
-#endif
- if (object->internal &&
- object->alive &&
- !object->terminating &&
- object->pager_ready) {
+ if (reap_type == REAP_DATA_FLUSH || reap_type == REAP_TERMINATE) {
- /*
- * We're already holding a "paging in progress" reference
- * so the object can't disappear when we release the lock.
- */
+ if (p->busy || p->cleaning) {
- assert(object->paging_in_progress);
- pager = object->pager;
- vm_object_unlock(object);
+ vm_page_unlock_queues();
+ /*
+ * free the pages reclaimed so far
+ */
+ VM_OBJ_REAP_FREELIST(local_free_q,
+ disconnect_on_release);
+
+ PAGE_SLEEP(object, p, THREAD_UNINT);
- kr = memory_object_data_request(
- pager,
- offset + object->paging_offset,
- 0, /* just poke the pager */
- VM_PROT_READ,
- NULL);
+ goto restart_after_sleep;
+ }
+ if (p->laundry)
+ vm_pageout_steal_laundry(p, TRUE);
+ }
+ switch (reap_type) {
- vm_object_lock(object);
+ case REAP_DATA_FLUSH:
+ if (VM_PAGE_WIRED(p)) {
+ /*
+ * this is an odd case... perhaps we should
+ * zero-fill this page since we're conceptually
+ * tossing its data at this point, but leaving
+ * it on the object to honor the 'wire' contract
+ */
+ continue;
+ }
+ break;
+
+ case REAP_PURGEABLE:
+ if (VM_PAGE_WIRED(p)) {
+ /*
+ * can't purge a wired page
+ */
+ vm_page_purged_wired++;
+ continue;
+ }
+ if (p->laundry && !p->busy && !p->cleaning)
+ vm_pageout_steal_laundry(p, TRUE);
+
+ if (p->cleaning || p->laundry || p->absent) {
+ /*
+ * page is being acted upon,
+ * so don't mess with it
+ */
+ vm_page_purged_others++;
+ continue;
+ }
+ if (p->busy) {
+ /*
+ * We can't reclaim a busy page but we can
+ * make it more likely to be paged (it's not wired) to make
+ * sure that it gets considered by
+ * vm_pageout_scan() later.
+ */
+ if (VM_PAGE_PAGEABLE(p))
+ vm_page_deactivate(p);
+ vm_page_purged_busy++;
+ continue;
+ }
- if (kr == KERN_SUCCESS) {
+ assert(VM_PAGE_OBJECT(p) != kernel_object);
/*
- * We found the page
+ * we can discard this page...
*/
+ if (p->pmapped == TRUE) {
+ /*
+ * unmap the page
+ */
+ pmap_disconnect_options(VM_PAGE_GET_PHYS_PAGE(p), PMAP_OPTIONS_NOFLUSH | PMAP_OPTIONS_NOREFMOD, (void *)&pmap_flush_context_storage);
+ }
+ vm_page_purged_count++;
- return TRUE;
- }
- }
-
- return FALSE;
-}
-
+ break;
-/*
- * Deactivate the pages in the specified object and range. If kill_page is set, also discard any
- * page modified state from the pmap. Update the chunk_state as we go along. The caller must specify
- * a size that is less than or equal to the CHUNK_SIZE.
- */
+ case REAP_TERMINATE:
+ if (p->absent || p->private) {
+ /*
+ * For private pages, VM_PAGE_FREE just
+ * leaves the page structure around for
+ * its owner to clean up. For absent
+ * pages, the structure is returned to
+ * the appropriate pool.
+ */
+ break;
+ }
+ if (p->fictitious) {
+ assert (VM_PAGE_GET_PHYS_PAGE(p) == vm_page_guard_addr);
+ break;
+ }
+ if (!p->dirty && p->wpmapped)
+ p->dirty = pmap_is_modified(VM_PAGE_GET_PHYS_PAGE(p));
-static void
-deactivate_pages_in_object(
- vm_object_t object,
- vm_object_offset_t offset,
- vm_object_size_t size,
- boolean_t kill_page,
- boolean_t reusable_page,
-#if !MACH_ASSERT
- __unused
-#endif
- boolean_t all_reusable,
- chunk_state_t *chunk_state)
-{
- vm_page_t m;
- int p;
- struct dw dw_array[DELAYED_WORK_LIMIT];
- struct dw *dwp;
- int dw_count;
- unsigned int reusable = 0;
+ if ((p->dirty || p->precious) && !p->error && object->alive) {
+ assert(!object->internal);
+
+ p->free_when_done = TRUE;
- /*
- * Examine each page in the chunk. The variable 'p' is the page number relative to the start of the
- * chunk. Since this routine is called once for each level in the shadow chain, the chunk_state may
- * have pages marked as having been processed already. We stop the loop early if we find we've handled
- * all the pages in the chunk.
- */
+ if (!p->laundry) {
+ vm_page_queues_remove(p, TRUE);
+ /*
+ * flush page... page will be freed
+ * upon completion of I/O
+ */
+ (void)vm_pageout_cluster(p, FALSE, FALSE);
+ }
+ vm_page_unlock_queues();
+ /*
+ * free the pages reclaimed so far
+ */
+ VM_OBJ_REAP_FREELIST(local_free_q,
+ disconnect_on_release);
- dwp = &dw_array[0];
- dw_count = 0;
+ vm_object_paging_wait(object, THREAD_UNINT);
- for(p = 0; size && CHUNK_NOT_COMPLETE(*chunk_state); p++, size -= PAGE_SIZE_64, offset += PAGE_SIZE_64) {
+ goto restart_after_sleep;
+ }
+ break;
+ case REAP_REAP:
+ break;
+ }
+ vm_page_free_prepare_queues(p);
+ assert(p->pageq.next == 0 && p->pageq.prev == 0);
/*
- * If this offset has already been found and handled in a higher level object, then don't
- * do anything with it in the current shadow object.
+ * Add this page to our list of reclaimed pages,
+ * to be freed later.
*/
+ p->snext = local_free_q;
+ local_free_q = p;
+ }
+ vm_page_unlock_queues();
- if (PAGE_ALREADY_HANDLED(*chunk_state, p))
- continue;
-
- /*
- * See if the page at this offset is around. First check to see if the page is resident,
- * then if not, check the existence map or with the pager.
- */
+ /*
+ * Free the remaining reclaimed pages
+ */
+ if (reap_type == REAP_PURGEABLE)
+ pmap_flush(&pmap_flush_context_storage);
- if ((m = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
+ VM_OBJ_REAP_FREELIST(local_free_q,
+ disconnect_on_release);
+}
- /*
- * We found a page we were looking for. Mark it as "handled" now in the chunk_state
- * so that we won't bother looking for a page at this offset again if there are more
- * shadow objects. Then deactivate the page.
- */
- MARK_PAGE_HANDLED(*chunk_state, p);
-
- if (( !VM_PAGE_WIRED(m)) && (!m->private) && (!m->gobbled) && (!m->busy)) {
- int clear_refmod;
-
- assert(!m->laundry);
-
- clear_refmod = VM_MEM_REFERENCED;
- dwp->dw_mask = DW_clear_reference;
+void
+vm_object_reap_async(
+ vm_object_t object)
+{
+ vm_object_lock_assert_exclusive(object);
- if ((kill_page) && (object->internal)) {
- m->precious = FALSE;
- m->dirty = FALSE;
+ vm_object_reaper_lock_spin();
- clear_refmod |= VM_MEM_MODIFIED;
-#if CONFIG_EMBEDDED
- dwp->dw_mask |= DW_move_page;
-#endif
-#if MACH_PAGEMAP
- vm_external_state_clr(object->existence_map, offset);
-#endif /* MACH_PAGEMAP */
+ vm_object_reap_count_async++;
- if (reusable_page && !m->reusable) {
- assert(!all_reusable);
- assert(!object->all_reusable);
- m->reusable = TRUE;
- object->reusable_page_count++;
- assert(object->resident_page_count >= object->reusable_page_count);
- reusable++;
- }
- }
- pmap_clear_refmod(m->phys_page, clear_refmod);
+ /* enqueue the VM object... */
+ queue_enter(&vm_object_reaper_queue, object,
+ vm_object_t, cached_list);
- if (!m->throttled && !(reusable_page || all_reusable))
- dwp->dw_mask |= DW_move_page;
- /*
- * dw_do_work may need to drop the object lock
- * if it does, we need the pages its looking at to
- * be held stable via the busy bit.
- */
- m->busy = TRUE;
- dwp->dw_mask |= (DW_clear_busy | DW_PAGE_WAKEUP);
+ vm_object_reaper_unlock();
- dwp->dw_m = m;
- dwp++;
- dw_count++;
+ /* ... and wake up the reaper thread */
+ thread_wakeup((event_t) &vm_object_reaper_queue);
+}
- if (dw_count >= DELAYED_WORK_LIMIT) {
- if (reusable) {
- OSAddAtomic(reusable,
- &vm_page_stats_reusable.reusable_count);
- vm_page_stats_reusable.reusable += reusable;
- reusable = 0;
- }
- dw_do_work(object, &dw_array[0], dw_count);
- dwp = &dw_array[0];
- dw_count = 0;
- }
- }
+void
+vm_object_reaper_thread(void)
+{
+ vm_object_t object, shadow_object;
- } else {
+ vm_object_reaper_lock_spin();
- /*
- * The page at this offset isn't memory resident, check to see if it's
- * been paged out. If so, mark it as handled so we don't bother looking
- * for it in the shadow chain.
- */
+ while (!queue_empty(&vm_object_reaper_queue)) {
+ queue_remove_first(&vm_object_reaper_queue,
+ object,
+ vm_object_t,
+ cached_list);
- if (page_is_paged_out(object, offset)) {
- MARK_PAGE_HANDLED(*chunk_state, p);
+ vm_object_reaper_unlock();
+ vm_object_lock(object);
- /*
- * If we're killing a non-resident page, then clear the page in the existence
- * map so we don't bother paging it back in if it's touched again in the future.
- */
+ assert(object->terminating);
+ assert(!object->alive);
+
+ /*
+ * The pageout daemon might be playing with our pages.
+ * Now that the object is dead, it won't touch any more
+ * pages, but some pages might already be on their way out.
+ * Hence, we wait until the active paging activities have
+ * ceased before we break the association with the pager
+ * itself.
+ */
+ while (object->paging_in_progress != 0 ||
+ object->activity_in_progress != 0) {
+ vm_object_wait(object,
+ VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
+ THREAD_UNINT);
+ vm_object_lock(object);
+ }
- if ((kill_page) && (object->internal)) {
-#if MACH_PAGEMAP
- vm_external_state_clr(object->existence_map, offset);
-#endif /* MACH_PAGEMAP */
- }
- }
+ shadow_object =
+ object->pageout ? VM_OBJECT_NULL : object->shadow;
+
+ vm_object_reap(object);
+ /* cache is unlocked and object is no longer valid */
+ object = VM_OBJECT_NULL;
+
+ if (shadow_object != VM_OBJECT_NULL) {
+ /*
+ * Drop the reference "object" was holding on
+ * its shadow object.
+ */
+ vm_object_deallocate(shadow_object);
+ shadow_object = VM_OBJECT_NULL;
}
+ vm_object_reaper_lock_spin();
}
- if (reusable) {
- OSAddAtomic(reusable, &vm_page_stats_reusable.reusable_count);
- vm_page_stats_reusable.reusable += reusable;
- reusable = 0;
- }
-
- if (dw_count)
- dw_do_work(object, &dw_array[0], dw_count);
-}
+ /* wait for more work... */
+ assert_wait((event_t) &vm_object_reaper_queue, THREAD_UNINT);
+
+ vm_object_reaper_unlock();
+ thread_block((thread_continue_t) vm_object_reaper_thread);
+ /*NOTREACHED*/
+}
/*
- * Deactive a "chunk" of the given range of the object starting at offset. A "chunk"
- * will always be less than or equal to the given size. The total range is divided up
- * into chunks for efficiency and performance related to the locks and handling the shadow
- * chain. This routine returns how much of the given "size" it actually processed. It's
- * up to the caler to loop and keep calling this routine until the entire range they want
- * to process has been done.
+ * Routine: vm_object_pager_wakeup
+ * Purpose: Wake up anyone waiting for termination of a pager.
*/
-static vm_object_size_t
-deactivate_a_chunk(
- vm_object_t orig_object,
- vm_object_offset_t offset,
- vm_object_size_t size,
- boolean_t kill_page,
- boolean_t reusable_page,
- boolean_t all_reusable)
+static void
+vm_object_pager_wakeup(
+ memory_object_t pager)
{
- vm_object_t object;
- vm_object_t tmp_object;
- vm_object_size_t length;
- chunk_state_t chunk_state;
-
+ vm_object_hash_entry_t entry;
+ boolean_t waiting = FALSE;
+ lck_mtx_t *lck;
/*
- * Get set to do a chunk. We'll do up to CHUNK_SIZE, but no more than the
- * remaining size the caller asked for.
+ * If anyone was waiting for the memory_object_terminate
+ * to be queued, wake them up now.
*/
+ lck = vm_object_hash_lock_spin(pager);
+ entry = vm_object_hash_lookup(pager, TRUE);
+ if (entry != VM_OBJECT_HASH_ENTRY_NULL)
+ waiting = entry->waiting;
+ vm_object_hash_unlock(lck);
- length = MIN(size, CHUNK_SIZE);
-
- /*
- * The chunk_state keeps track of which pages we've already processed if there's
- * a shadow chain on this object. At this point, we haven't done anything with this
- * range of pages yet, so initialize the state to indicate no pages processed yet.
- */
+ if (entry != VM_OBJECT_HASH_ENTRY_NULL) {
+ if (waiting)
+ thread_wakeup((event_t) pager);
+ vm_object_hash_entry_free(entry);
+ }
+}
- CHUNK_INIT(chunk_state, length);
- object = orig_object;
+/*
+ * Routine: vm_object_release_pager
+ * Purpose: Terminate the pager and, upon completion,
+ * release our last reference to it.
+ * just like memory_object_terminate, except
+ * that we wake up anyone blocked in vm_object_enter
+ * waiting for termination message to be queued
+ * before calling memory_object_init.
+ */
+static void
+vm_object_release_pager(
+ memory_object_t pager,
+ boolean_t hashed)
+{
/*
- * Start at the top level object and iterate around the loop once for each object
- * in the shadow chain. We stop processing early if we've already found all the pages
- * in the range. Otherwise we stop when we run out of shadow objects.
+ * Terminate the pager.
*/
- while (object && CHUNK_NOT_COMPLETE(chunk_state)) {
- vm_object_paging_begin(object);
-
- deactivate_pages_in_object(object, offset, length, kill_page, reusable_page, all_reusable, &chunk_state);
-
- vm_object_paging_end(object);
+ (void) memory_object_terminate(pager);
+ if (hashed == TRUE) {
/*
- * We've finished with this object, see if there's a shadow object. If
- * there is, update the offset and lock the new object. We also turn off
- * kill_page at this point since we only kill pages in the top most object.
+ * Wakeup anyone waiting for this terminate
+ * and remove the entry from the hash
*/
-
- tmp_object = object->shadow;
-
- if (tmp_object) {
- kill_page = FALSE;
- reusable_page = FALSE;
- all_reusable = FALSE;
- offset += object->shadow_offset;
- vm_object_lock(tmp_object);
- }
-
- if (object != orig_object)
- vm_object_unlock(object);
-
- object = tmp_object;
+ vm_object_pager_wakeup(pager);
}
-
- if (object && object != orig_object)
- vm_object_unlock(object);
-
- return length;
+ /*
+ * Release reference to pager.
+ */
+ memory_object_deallocate(pager);
}
-
-
/*
- * Move any resident pages in the specified range to the inactive queue. If kill_page is set,
- * we also clear the modified status of the page and "forget" any changes that have been made
- * to the page.
+ * Routine: vm_object_destroy
+ * Purpose:
+ * Shut down a VM object, despite the
+ * presence of address map (or other) references
+ * to the vm_object.
*/
-
-__private_extern__ void
-vm_object_deactivate_pages(
+kern_return_t
+vm_object_destroy(
vm_object_t object,
- vm_object_offset_t offset,
- vm_object_size_t size,
- boolean_t kill_page,
- boolean_t reusable_page)
+ __unused kern_return_t reason)
{
- vm_object_size_t length;
- boolean_t all_reusable;
+ memory_object_t old_pager;
+
+ if (object == VM_OBJECT_NULL)
+ return(KERN_SUCCESS);
/*
- * We break the range up into chunks and do one chunk at a time. This is for
- * efficiency and performance while handling the shadow chains and the locks.
- * The deactivate_a_chunk() function returns how much of the range it processed.
- * We keep calling this routine until the given size is exhausted.
+ * Remove the pager association immediately.
+ *
+ * This will prevent the memory manager from further
+ * meddling. [If it wanted to flush data or make
+ * other changes, it should have done so before performing
+ * the destroy call.]
*/
+ vm_object_lock(object);
+ object->can_persist = FALSE;
+ object->named = FALSE;
+ object->alive = FALSE;
- all_reusable = FALSE;
- if (reusable_page &&
- object->size != 0 &&
- object->size == size &&
- object->reusable_page_count == 0) {
- all_reusable = TRUE;
- reusable_page = FALSE;
+ if (object->hashed) {
+ lck_mtx_t *lck;
+ /*
+ * Rip out the pager from the vm_object now...
+ */
+ lck = vm_object_hash_lock_spin(object->pager);
+ vm_object_remove(object);
+ vm_object_hash_unlock(lck);
}
+ old_pager = object->pager;
+ object->pager = MEMORY_OBJECT_NULL;
+ if (old_pager != MEMORY_OBJECT_NULL)
+ memory_object_control_disable(object->pager_control);
- while (size) {
- length = deactivate_a_chunk(object, offset, size, kill_page, reusable_page, all_reusable);
+ /*
+ * Wait for the existing paging activity (that got
+ * through before we nulled out the pager) to subside.
+ */
- size -= length;
- offset += length;
- }
+ vm_object_paging_wait(object, THREAD_UNINT);
+ vm_object_unlock(object);
- if (all_reusable) {
- if (!object->all_reusable) {
- unsigned int reusable;
+ /*
+ * Terminate the object now.
+ */
+ if (old_pager != MEMORY_OBJECT_NULL) {
+ vm_object_release_pager(old_pager, object->hashed);
+
+ /*
+ * JMM - Release the caller's reference. This assumes the
+ * caller had a reference to release, which is a big (but
+ * currently valid) assumption if this is driven from the
+ * vnode pager (it is holding a named reference when making
+ * this call)..
+ */
+ vm_object_deallocate(object);
- object->all_reusable = TRUE;
- assert(object->reusable_page_count == 0);
- /* update global stats */
- reusable = object->resident_page_count;
- OSAddAtomic(reusable,
- &vm_page_stats_reusable.reusable_count);
- vm_page_stats_reusable.reusable += reusable;
- vm_page_stats_reusable.all_reusable_calls++;
- }
- } else if (reusable_page) {
- vm_page_stats_reusable.partial_reusable_calls++;
}
+ return(KERN_SUCCESS);
}
-void
-vm_object_reuse_pages(
- vm_object_t object,
- vm_object_offset_t start_offset,
- vm_object_offset_t end_offset,
- boolean_t allow_partial_reuse)
-{
- vm_object_offset_t cur_offset;
- vm_page_t m;
- unsigned int reused, reusable;
-
-#define VM_OBJECT_REUSE_PAGE(object, m, reused) \
- MACRO_BEGIN \
- if ((m) != VM_PAGE_NULL && \
- (m)->reusable) { \
- assert((object)->reusable_page_count <= \
- (object)->resident_page_count); \
- assert((object)->reusable_page_count > 0); \
- (object)->reusable_page_count--; \
- (m)->reusable = FALSE; \
- (reused)++; \
- } \
- MACRO_END
- reused = 0;
- reusable = 0;
+#if VM_OBJECT_CACHE
- vm_object_lock_assert_exclusive(object);
+#define VM_OBJ_DEACT_ALL_STATS DEBUG
+#if VM_OBJ_DEACT_ALL_STATS
+uint32_t vm_object_deactivate_all_pages_batches = 0;
+uint32_t vm_object_deactivate_all_pages_pages = 0;
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+/*
+ * vm_object_deactivate_all_pages
+ *
+ * Deactivate all pages in the specified object. (Keep its pages
+ * in memory even though it is no longer referenced.)
+ *
+ * The object must be locked.
+ */
+static void
+vm_object_deactivate_all_pages(
+ vm_object_t object)
+{
+ vm_page_t p;
+ int loop_count;
+#if VM_OBJ_DEACT_ALL_STATS
+ int pages_count;
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+#define V_O_D_A_P_MAX_BATCH 256
- if (object->all_reusable) {
- assert(object->reusable_page_count == 0);
- object->all_reusable = FALSE;
- if (end_offset - start_offset == object->size ||
- !allow_partial_reuse) {
- vm_page_stats_reusable.all_reuse_calls++;
- reused = object->resident_page_count;
- } else {
- vm_page_stats_reusable.partial_reuse_calls++;
- queue_iterate(&object->memq, m, vm_page_t, listq) {
- if (m->offset < start_offset ||
- m->offset >= end_offset) {
- m->reusable = TRUE;
- object->reusable_page_count++;
- assert(object->resident_page_count >= object->reusable_page_count);
- continue;
- } else {
- assert(!m->reusable);
- reused++;
- }
- }
- }
- } else if (object->resident_page_count >
- ((end_offset - start_offset) >> PAGE_SHIFT)) {
- vm_page_stats_reusable.partial_reuse_calls++;
- for (cur_offset = start_offset;
- cur_offset < end_offset;
- cur_offset += PAGE_SIZE_64) {
- if (object->reusable_page_count == 0) {
- break;
- }
- m = vm_page_lookup(object, cur_offset);
- VM_OBJECT_REUSE_PAGE(object, m, reused);
+ loop_count = BATCH_LIMIT(V_O_D_A_P_MAX_BATCH);
+#if VM_OBJ_DEACT_ALL_STATS
+ pages_count = 0;
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+ vm_page_lock_queues();
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+ if (--loop_count == 0) {
+#if VM_OBJ_DEACT_ALL_STATS
+ hw_atomic_add(&vm_object_deactivate_all_pages_batches,
+ 1);
+ hw_atomic_add(&vm_object_deactivate_all_pages_pages,
+ pages_count);
+ pages_count = 0;
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+ lck_mtx_yield(&vm_page_queue_lock);
+ loop_count = BATCH_LIMIT(V_O_D_A_P_MAX_BATCH);
}
- } else {
- vm_page_stats_reusable.partial_reuse_calls++;
- queue_iterate(&object->memq, m, vm_page_t, listq) {
- if (object->reusable_page_count == 0) {
- break;
- }
- if (m->offset < start_offset ||
- m->offset >= end_offset) {
- continue;
- }
- VM_OBJECT_REUSE_PAGE(object, m, reused);
+ if (!p->busy && (p->vm_page_q_state != VM_PAGE_ON_THROTTLED_Q)) {
+#if VM_OBJ_DEACT_ALL_STATS
+ pages_count++;
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+ vm_page_deactivate(p);
}
}
-
- /* update global stats */
- OSAddAtomic(reusable-reused, &vm_page_stats_reusable.reusable_count);
- vm_page_stats_reusable.reused += reused;
- vm_page_stats_reusable.reusable += reusable;
+#if VM_OBJ_DEACT_ALL_STATS
+ if (pages_count) {
+ hw_atomic_add(&vm_object_deactivate_all_pages_batches, 1);
+ hw_atomic_add(&vm_object_deactivate_all_pages_pages,
+ pages_count);
+ pages_count = 0;
+ }
+#endif /* VM_OBJ_DEACT_ALL_STATS */
+ vm_page_unlock_queues();
}
+#endif /* VM_OBJECT_CACHE */
+
+
/*
- * Routine: vm_object_pmap_protect
- *
- * Purpose:
- * Reduces the permission for all physical
- * pages in the specified object range.
- *
- * If removing write permission only, it is
- * sufficient to protect only the pages in
- * the top-level object; only those pages may
- * have write permission.
- *
- * If removing all access, we must follow the
- * shadow chain from the top-level object to
- * remove access to all pages in shadowed objects.
+ * The "chunk" macros are used by routines below when looking for pages to deactivate. These
+ * exist because of the need to handle shadow chains. When deactivating pages, we only
+ * want to deactive the ones at the top most level in the object chain. In order to do
+ * this efficiently, the specified address range is divided up into "chunks" and we use
+ * a bit map to keep track of which pages have already been processed as we descend down
+ * the shadow chain. These chunk macros hide the details of the bit map implementation
+ * as much as we can.
*
- * The object must *not* be locked. The object must
- * be temporary/internal.
+ * For convenience, we use a 64-bit data type as the bit map, and therefore a chunk is
+ * set to 64 pages. The bit map is indexed from the low-order end, so that the lowest
+ * order bit represents page 0 in the current range and highest order bit represents
+ * page 63.
*
- * If pmap is not NULL, this routine assumes that
- * the only mappings for the pages are in that
- * pmap.
+ * For further convenience, we also use negative logic for the page state in the bit map.
+ * The bit is set to 1 to indicate it has not yet been seen, and to 0 to indicate it has
+ * been processed. This way we can simply test the 64-bit long word to see if it's zero
+ * to easily tell if the whole range has been processed. Therefore, the bit map starts
+ * out with all the bits set. The macros below hide all these details from the caller.
*/
-__private_extern__ void
-vm_object_pmap_protect(
- register vm_object_t object,
- register vm_object_offset_t offset,
- vm_object_size_t size,
- pmap_t pmap,
- vm_map_offset_t pmap_start,
- vm_prot_t prot)
-{
- if (object == VM_OBJECT_NULL)
- return;
- size = vm_object_round_page(size);
- offset = vm_object_trunc_page(offset);
+#define PAGES_IN_A_CHUNK 64 /* The number of pages in the chunk must */
+ /* be the same as the number of bits in */
+ /* the chunk_state_t type. We use 64 */
+ /* just for convenience. */
- vm_object_lock(object);
+#define CHUNK_SIZE (PAGES_IN_A_CHUNK * PAGE_SIZE_64) /* Size of a chunk in bytes */
- if (object->phys_contiguous) {
- if (pmap != NULL) {
- vm_object_unlock(object);
- pmap_protect(pmap, pmap_start, pmap_start + size, prot);
- } else {
- vm_object_offset_t phys_start, phys_end, phys_addr;
+typedef uint64_t chunk_state_t;
- phys_start = object->shadow_offset + offset;
- phys_end = phys_start + size;
- assert(phys_start <= phys_end);
- assert(phys_end <= object->shadow_offset + object->size);
- vm_object_unlock(object);
+/*
+ * The bit map uses negative logic, so we start out with all 64 bits set to indicate
+ * that no pages have been processed yet. Also, if len is less than the full CHUNK_SIZE,
+ * then we mark pages beyond the len as having been "processed" so that we don't waste time
+ * looking at pages in that range. This can save us from unnecessarily chasing down the
+ * shadow chain.
+ */
- for (phys_addr = phys_start;
- phys_addr < phys_end;
- phys_addr += PAGE_SIZE_64) {
- pmap_page_protect((ppnum_t) (phys_addr >> PAGE_SHIFT), prot);
- }
- }
- return;
- }
+#define CHUNK_INIT(c, len) \
+ MACRO_BEGIN \
+ uint64_t p; \
+ \
+ (c) = 0xffffffffffffffffLL; \
+ \
+ for (p = (len) / PAGE_SIZE_64; p < PAGES_IN_A_CHUNK; p++) \
+ MARK_PAGE_HANDLED(c, p); \
+ MACRO_END
- assert(object->internal);
- while (TRUE) {
- if (ptoa_64(object->resident_page_count) > size/2 && pmap != PMAP_NULL) {
- vm_object_unlock(object);
- pmap_protect(pmap, pmap_start, pmap_start + size, prot);
- return;
- }
+/*
+ * Return true if all pages in the chunk have not yet been processed.
+ */
- /* if we are doing large ranges with respect to resident */
- /* page count then we should interate over pages otherwise */
- /* inverse page look-up will be faster */
- if (ptoa_64(object->resident_page_count / 4) < size) {
- vm_page_t p;
- vm_object_offset_t end;
+#define CHUNK_NOT_COMPLETE(c) ((c) != 0)
- end = offset + size;
+/*
+ * Return true if the page at offset 'p' in the bit map has already been handled
+ * while processing a higher level object in the shadow chain.
+ */
- if (pmap != PMAP_NULL) {
- queue_iterate(&object->memq, p, vm_page_t, listq) {
- if (!p->fictitious &&
- (offset <= p->offset) && (p->offset < end)) {
- vm_map_offset_t start;
+#define PAGE_ALREADY_HANDLED(c, p) (((c) & (1LL << (p))) == 0)
- start = pmap_start + p->offset - offset;
- pmap_protect(pmap, start, start + PAGE_SIZE_64, prot);
- }
- }
- } else {
- queue_iterate(&object->memq, p, vm_page_t, listq) {
- if (!p->fictitious &&
- (offset <= p->offset) && (p->offset < end)) {
+/*
+ * Mark the page at offset 'p' in the bit map as having been processed.
+ */
- pmap_page_protect(p->phys_page, prot);
- }
- }
- }
- } else {
- vm_page_t p;
- vm_object_offset_t end;
- vm_object_offset_t target_off;
+#define MARK_PAGE_HANDLED(c, p) \
+MACRO_BEGIN \
+ (c) = (c) & ~(1LL << (p)); \
+MACRO_END
- end = offset + size;
- if (pmap != PMAP_NULL) {
- for(target_off = offset;
- target_off < end;
- target_off += PAGE_SIZE) {
- p = vm_page_lookup(object, target_off);
- if (p != VM_PAGE_NULL) {
- vm_object_offset_t start;
- start = pmap_start +
- (p->offset - offset);
- pmap_protect(pmap, start,
- start + PAGE_SIZE, prot);
- }
- }
- } else {
- for(target_off = offset;
- target_off < end; target_off += PAGE_SIZE) {
- p = vm_page_lookup(object, target_off);
- if (p != VM_PAGE_NULL) {
- pmap_page_protect(p->phys_page, prot);
- }
- }
- }
- }
+/*
+ * Return true if the page at the given offset has been paged out. Object is
+ * locked upon entry and returned locked.
+ */
- if (prot == VM_PROT_NONE) {
- /*
- * Must follow shadow chain to remove access
- * to pages in shadowed objects.
- */
- register vm_object_t next_object;
+static boolean_t
+page_is_paged_out(
+ vm_object_t object,
+ vm_object_offset_t offset)
+{
+ if (object->internal &&
+ object->alive &&
+ !object->terminating &&
+ object->pager_ready) {
- next_object = object->shadow;
- if (next_object != VM_OBJECT_NULL) {
- offset += object->shadow_offset;
- vm_object_lock(next_object);
- vm_object_unlock(object);
- object = next_object;
- }
- else {
- /*
- * End of chain - we are done.
- */
- break;
+ if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset)
+ == VM_EXTERNAL_STATE_EXISTS) {
+ return TRUE;
}
- }
- else {
- /*
- * Pages in shadowed objects may never have
- * write permission - we may stop here.
- */
- break;
- }
}
-
- vm_object_unlock(object);
+ return FALSE;
}
+
+
/*
- * Routine: vm_object_copy_slowly
- *
- * Description:
- * Copy the specified range of the source
- * virtual memory object without using
- * protection-based optimizations (such
- * as copy-on-write). The pages in the
- * region are actually copied.
- *
- * In/out conditions:
- * The caller must hold a reference and a lock
- * for the source virtual memory object. The source
- * object will be returned *unlocked*.
- *
- * Results:
- * If the copy is completed successfully, KERN_SUCCESS is
- * returned. If the caller asserted the interruptible
- * argument, and an interruption occurred while waiting
- * for a user-generated event, MACH_SEND_INTERRUPTED is
- * returned. Other values may be returned to indicate
- * hard errors during the copy operation.
+ * madvise_free_debug
*
- * A new virtual memory object is returned in a
- * parameter (_result_object). The contents of this
- * new object, starting at a zero offset, are a copy
- * of the source memory region. In the event of
- * an error, this parameter will contain the value
- * VM_OBJECT_NULL.
+ * To help debug madvise(MADV_FREE*) mis-usage, this triggers a
+ * zero-fill as soon as a page is affected by a madvise(MADV_FREE*), to
+ * simulate the loss of the page's contents as if the page had been
+ * reclaimed and then re-faulted.
*/
-__private_extern__ kern_return_t
-vm_object_copy_slowly(
- register vm_object_t src_object,
- vm_object_offset_t src_offset,
- vm_object_size_t size,
- boolean_t interruptible,
- vm_object_t *_result_object) /* OUT */
-{
- vm_object_t new_object;
- vm_object_offset_t new_offset;
-
- struct vm_object_fault_info fault_info;
+#if DEVELOPMENT || DEBUG
+int madvise_free_debug = 1;
+#else /* DEBUG */
+int madvise_free_debug = 0;
+#endif /* DEBUG */
- XPR(XPR_VM_OBJECT, "v_o_c_slowly obj 0x%x off 0x%x size 0x%x\n",
- src_object, src_offset, size, 0, 0);
+/*
+ * Deactivate the pages in the specified object and range. If kill_page is set, also discard any
+ * page modified state from the pmap. Update the chunk_state as we go along. The caller must specify
+ * a size that is less than or equal to the CHUNK_SIZE.
+ */
- if (size == 0) {
- vm_object_unlock(src_object);
- *_result_object = VM_OBJECT_NULL;
- return(KERN_INVALID_ARGUMENT);
- }
+static void
+deactivate_pages_in_object(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ boolean_t kill_page,
+ boolean_t reusable_page,
+ boolean_t all_reusable,
+ chunk_state_t *chunk_state,
+ pmap_flush_context *pfc,
+ struct pmap *pmap,
+ vm_map_offset_t pmap_offset)
+{
+ vm_page_t m;
+ int p;
+ struct vm_page_delayed_work dw_array[DEFAULT_DELAYED_WORK_LIMIT];
+ struct vm_page_delayed_work *dwp;
+ int dw_count;
+ int dw_limit;
+ unsigned int reusable = 0;
/*
- * Prevent destruction of the source object while we copy.
+ * Examine each page in the chunk. The variable 'p' is the page number relative to the start of the
+ * chunk. Since this routine is called once for each level in the shadow chain, the chunk_state may
+ * have pages marked as having been processed already. We stop the loop early if we find we've handled
+ * all the pages in the chunk.
*/
- vm_object_reference_locked(src_object);
- vm_object_unlock(src_object);
+ dwp = &dw_array[0];
+ dw_count = 0;
+ dw_limit = DELAYED_WORK_LIMIT(DEFAULT_DELAYED_WORK_LIMIT);
- /*
- * Create a new object to hold the copied pages.
- * A few notes:
- * We fill the new object starting at offset 0,
- * regardless of the input offset.
- * We don't bother to lock the new object within
- * this routine, since we have the only reference.
- */
+ for(p = 0; size && CHUNK_NOT_COMPLETE(*chunk_state); p++, size -= PAGE_SIZE_64, offset += PAGE_SIZE_64, pmap_offset += PAGE_SIZE_64) {
- new_object = vm_object_allocate(size);
- new_offset = 0;
+ /*
+ * If this offset has already been found and handled in a higher level object, then don't
+ * do anything with it in the current shadow object.
+ */
- assert(size == trunc_page_64(size)); /* Will the loop terminate? */
+ if (PAGE_ALREADY_HANDLED(*chunk_state, p))
+ continue;
+
+ /*
+ * See if the page at this offset is around. First check to see if the page is resident,
+ * then if not, check the existence map or with the pager.
+ */
- fault_info.interruptible = interruptible;
- fault_info.behavior = VM_BEHAVIOR_SEQUENTIAL;
- fault_info.user_tag = 0;
- fault_info.lo_offset = src_offset;
- fault_info.hi_offset = src_offset + size;
- fault_info.no_cache = FALSE;
- fault_info.stealth = TRUE;
+ if ((m = vm_page_lookup(object, offset)) != VM_PAGE_NULL) {
- for ( ;
- size != 0 ;
- src_offset += PAGE_SIZE_64,
- new_offset += PAGE_SIZE_64, size -= PAGE_SIZE_64
- ) {
- vm_page_t new_page;
- vm_fault_return_t result;
+ /*
+ * We found a page we were looking for. Mark it as "handled" now in the chunk_state
+ * so that we won't bother looking for a page at this offset again if there are more
+ * shadow objects. Then deactivate the page.
+ */
- vm_object_lock(new_object);
+ MARK_PAGE_HANDLED(*chunk_state, p);
+
+ if (( !VM_PAGE_WIRED(m)) && (!m->private) && (!m->gobbled) && (!m->busy) && (!m->laundry)) {
+ int clear_refmod;
+ int pmap_options;
+
+ dwp->dw_mask = 0;
- while ((new_page = vm_page_alloc(new_object, new_offset))
- == VM_PAGE_NULL) {
+ pmap_options = 0;
+ clear_refmod = VM_MEM_REFERENCED;
+ dwp->dw_mask |= DW_clear_reference;
- vm_object_unlock(new_object);
+ if ((kill_page) && (object->internal)) {
+ if (madvise_free_debug) {
+ /*
+ * zero-fill the page now
+ * to simulate it being
+ * reclaimed and re-faulted.
+ */
+ pmap_zero_page(VM_PAGE_GET_PHYS_PAGE(m));
+ }
+ m->precious = FALSE;
+ m->dirty = FALSE;
- if (!vm_page_wait(interruptible)) {
- vm_object_deallocate(new_object);
- vm_object_deallocate(src_object);
- *_result_object = VM_OBJECT_NULL;
- return(MACH_SEND_INTERRUPTED);
- }
- vm_object_lock(new_object);
- }
- vm_object_unlock(new_object);
+ clear_refmod |= VM_MEM_MODIFIED;
+ if (m->vm_page_q_state == VM_PAGE_ON_THROTTLED_Q) {
+ /*
+ * This page is now clean and
+ * reclaimable. Move it out
+ * of the throttled queue, so
+ * that vm_pageout_scan() can
+ * find it.
+ */
+ dwp->dw_mask |= DW_move_page;
+ }
- do {
- vm_prot_t prot = VM_PROT_READ;
- vm_page_t _result_page;
- vm_page_t top_page;
- register
- vm_page_t result_page;
- kern_return_t error_code;
+ VM_COMPRESSOR_PAGER_STATE_CLR(object, offset);
- vm_object_lock(src_object);
- vm_object_paging_begin(src_object);
+ if (reusable_page && !m->reusable) {
+ assert(!all_reusable);
+ assert(!object->all_reusable);
+ m->reusable = TRUE;
+ object->reusable_page_count++;
+ assert(object->resident_page_count >= object->reusable_page_count);
+ reusable++;
+ /*
+ * Tell pmap this page is now
+ * "reusable" (to update pmap
+ * stats for all mappings).
+ */
+ pmap_options |= PMAP_OPTIONS_SET_REUSABLE;
+ }
+ }
+ pmap_options |= PMAP_OPTIONS_NOFLUSH;
+ pmap_clear_refmod_options(VM_PAGE_GET_PHYS_PAGE(m),
+ clear_refmod,
+ pmap_options,
+ (void *)pfc);
- if (size > (vm_size_t) -1) {
- /* 32-bit overflow */
- fault_info.cluster_size = (vm_size_t) (0 - PAGE_SIZE);
- } else {
- fault_info.cluster_size = (vm_size_t) size;
- assert(fault_info.cluster_size == size);
- }
+ if ((m->vm_page_q_state != VM_PAGE_ON_THROTTLED_Q) && !(reusable_page || all_reusable))
+ dwp->dw_mask |= DW_move_page;
+
+ if (dwp->dw_mask)
+ VM_PAGE_ADD_DELAYED_WORK(dwp, m,
+ dw_count);
- XPR(XPR_VM_FAULT,"vm_object_copy_slowly -> vm_fault_page",0,0,0,0,0);
- result = vm_fault_page(src_object, src_offset,
- VM_PROT_READ, FALSE,
- &prot, &_result_page, &top_page,
- (int *)0,
- &error_code, FALSE, FALSE, &fault_info);
+ if (dw_count >= dw_limit) {
+ if (reusable) {
+ OSAddAtomic(reusable,
+ &vm_page_stats_reusable.reusable_count);
+ vm_page_stats_reusable.reusable += reusable;
+ reusable = 0;
+ }
+ vm_page_do_delayed_work(object, VM_KERN_MEMORY_NONE, &dw_array[0], dw_count);
- switch(result) {
- case VM_FAULT_SUCCESS:
- result_page = _result_page;
+ dwp = &dw_array[0];
+ dw_count = 0;
+ }
+ }
- /*
- * We don't need to hold the object
- * lock -- the busy page will be enough.
- * [We don't care about picking up any
- * new modifications.]
- *
- * Copy the page to the new object.
- *
- * POLICY DECISION:
- * If result_page is clean,
- * we could steal it instead
- * of copying.
- */
+ } else {
- vm_object_unlock(result_page->object);
- vm_page_copy(result_page, new_page);
+ /*
+ * The page at this offset isn't memory resident, check to see if it's
+ * been paged out. If so, mark it as handled so we don't bother looking
+ * for it in the shadow chain.
+ */
+
+ if (page_is_paged_out(object, offset)) {
+ MARK_PAGE_HANDLED(*chunk_state, p);
/*
- * Let go of both pages (make them
- * not busy, perform wakeup, activate).
+ * If we're killing a non-resident page, then clear the page in the existence
+ * map so we don't bother paging it back in if it's touched again in the future.
*/
- vm_object_lock(new_object);
- new_page->dirty = TRUE;
- PAGE_WAKEUP_DONE(new_page);
- vm_object_unlock(new_object);
-
- vm_object_lock(result_page->object);
- PAGE_WAKEUP_DONE(result_page);
- vm_page_lockspin_queues();
- if (!result_page->active &&
- !result_page->inactive &&
- !result_page->throttled)
- vm_page_activate(result_page);
- vm_page_activate(new_page);
- vm_page_unlock_queues();
+ if ((kill_page) && (object->internal)) {
- /*
- * Release paging references and
- * top-level placeholder page, if any.
- */
+ VM_COMPRESSOR_PAGER_STATE_CLR(object, offset);
- vm_fault_cleanup(result_page->object,
- top_page);
-
- break;
-
- case VM_FAULT_RETRY:
- break;
+ if (pmap != PMAP_NULL) {
+ /*
+ * Tell pmap that this page
+ * is no longer mapped, to
+ * adjust the footprint ledger
+ * because this page is no
+ * longer compressed.
+ */
+ pmap_remove_options(
+ pmap,
+ pmap_offset,
+ (pmap_offset +
+ PAGE_SIZE),
+ PMAP_OPTIONS_REMOVE);
+ }
+ }
+ }
+ }
+ }
- case VM_FAULT_FICTITIOUS_SHORTAGE:
- vm_page_more_fictitious();
- break;
+ if (reusable) {
+ OSAddAtomic(reusable, &vm_page_stats_reusable.reusable_count);
+ vm_page_stats_reusable.reusable += reusable;
+ reusable = 0;
+ }
+
+ if (dw_count)
+ vm_page_do_delayed_work(object, VM_KERN_MEMORY_NONE, &dw_array[0], dw_count);
+}
- case VM_FAULT_MEMORY_SHORTAGE:
- if (vm_page_wait(interruptible))
- break;
- /* fall thru */
- case VM_FAULT_INTERRUPTED:
- vm_object_lock(new_object);
- VM_PAGE_FREE(new_page);
- vm_object_unlock(new_object);
-
- vm_object_deallocate(new_object);
- vm_object_deallocate(src_object);
- *_result_object = VM_OBJECT_NULL;
- return(MACH_SEND_INTERRUPTED);
+/*
+ * Deactive a "chunk" of the given range of the object starting at offset. A "chunk"
+ * will always be less than or equal to the given size. The total range is divided up
+ * into chunks for efficiency and performance related to the locks and handling the shadow
+ * chain. This routine returns how much of the given "size" it actually processed. It's
+ * up to the caler to loop and keep calling this routine until the entire range they want
+ * to process has been done.
+ */
- case VM_FAULT_SUCCESS_NO_VM_PAGE:
- /* success but no VM page: fail */
- vm_object_paging_end(src_object);
- vm_object_unlock(src_object);
- /*FALLTHROUGH*/
- case VM_FAULT_MEMORY_ERROR:
- /*
- * A policy choice:
- * (a) ignore pages that we can't
- * copy
- * (b) return the null object if
- * any page fails [chosen]
- */
+static vm_object_size_t
+deactivate_a_chunk(
+ vm_object_t orig_object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ boolean_t kill_page,
+ boolean_t reusable_page,
+ boolean_t all_reusable,
+ pmap_flush_context *pfc,
+ struct pmap *pmap,
+ vm_map_offset_t pmap_offset)
+{
+ vm_object_t object;
+ vm_object_t tmp_object;
+ vm_object_size_t length;
+ chunk_state_t chunk_state;
- vm_object_lock(new_object);
- VM_PAGE_FREE(new_page);
- vm_object_unlock(new_object);
- vm_object_deallocate(new_object);
- vm_object_deallocate(src_object);
- *_result_object = VM_OBJECT_NULL;
- return(error_code ? error_code:
- KERN_MEMORY_ERROR);
+ /*
+ * Get set to do a chunk. We'll do up to CHUNK_SIZE, but no more than the
+ * remaining size the caller asked for.
+ */
- default:
- panic("vm_object_copy_slowly: unexpected error"
- " 0x%x from vm_fault_page()\n", result);
- }
- } while (result != VM_FAULT_SUCCESS);
- }
+ length = MIN(size, CHUNK_SIZE);
/*
- * Lose the extra reference, and return our object.
+ * The chunk_state keeps track of which pages we've already processed if there's
+ * a shadow chain on this object. At this point, we haven't done anything with this
+ * range of pages yet, so initialize the state to indicate no pages processed yet.
*/
- vm_object_deallocate(src_object);
- *_result_object = new_object;
- return(KERN_SUCCESS);
-}
-
-/*
- * Routine: vm_object_copy_quickly
- *
- * Purpose:
- * Copy the specified range of the source virtual
- * memory object, if it can be done without waiting
- * for user-generated events.
- *
- * Results:
- * If the copy is successful, the copy is returned in
- * the arguments; otherwise, the arguments are not
- * affected.
- *
- * In/out conditions:
- * The object should be unlocked on entry and exit.
- */
-/*ARGSUSED*/
-__private_extern__ boolean_t
-vm_object_copy_quickly(
- vm_object_t *_object, /* INOUT */
- __unused vm_object_offset_t offset, /* IN */
- __unused vm_object_size_t size, /* IN */
- boolean_t *_src_needs_copy, /* OUT */
- boolean_t *_dst_needs_copy) /* OUT */
-{
- vm_object_t object = *_object;
- memory_object_copy_strategy_t copy_strategy;
+ CHUNK_INIT(chunk_state, length);
+ object = orig_object;
- XPR(XPR_VM_OBJECT, "v_o_c_quickly obj 0x%x off 0x%x size 0x%x\n",
- *_object, offset, size, 0, 0);
- if (object == VM_OBJECT_NULL) {
- *_src_needs_copy = FALSE;
- *_dst_needs_copy = FALSE;
- return(TRUE);
- }
+ /*
+ * Start at the top level object and iterate around the loop once for each object
+ * in the shadow chain. We stop processing early if we've already found all the pages
+ * in the range. Otherwise we stop when we run out of shadow objects.
+ */
- vm_object_lock(object);
+ while (object && CHUNK_NOT_COMPLETE(chunk_state)) {
+ vm_object_paging_begin(object);
- copy_strategy = object->copy_strategy;
+ deactivate_pages_in_object(object, offset, length, kill_page, reusable_page, all_reusable, &chunk_state, pfc, pmap, pmap_offset);
- switch (copy_strategy) {
- case MEMORY_OBJECT_COPY_SYMMETRIC:
+ vm_object_paging_end(object);
/*
- * Symmetric copy strategy.
- * Make another reference to the object.
- * Leave object/offset unchanged.
+ * We've finished with this object, see if there's a shadow object. If
+ * there is, update the offset and lock the new object. We also turn off
+ * kill_page at this point since we only kill pages in the top most object.
*/
- vm_object_reference_locked(object);
- object->shadowed = TRUE;
- vm_object_unlock(object);
+ tmp_object = object->shadow;
- /*
- * Both source and destination must make
- * shadows, and the source must be made
- * read-only if not already.
- */
+ if (tmp_object) {
+ kill_page = FALSE;
+ reusable_page = FALSE;
+ all_reusable = FALSE;
+ offset += object->vo_shadow_offset;
+ vm_object_lock(tmp_object);
+ }
- *_src_needs_copy = TRUE;
- *_dst_needs_copy = TRUE;
+ if (object != orig_object)
+ vm_object_unlock(object);
- break;
+ object = tmp_object;
+ }
- case MEMORY_OBJECT_COPY_DELAY:
- vm_object_unlock(object);
- return(FALSE);
+ if (object && object != orig_object)
+ vm_object_unlock(object);
- default:
- vm_object_unlock(object);
- return(FALSE);
- }
- return(TRUE);
+ return length;
}
-static int copy_call_count = 0;
-static int copy_call_sleep_count = 0;
-static int copy_call_restart_count = 0;
+
/*
- * Routine: vm_object_copy_call [internal]
- *
- * Description:
- * Copy the source object (src_object), using the
- * user-managed copy algorithm.
- *
- * In/out conditions:
- * The source object must be locked on entry. It
- * will be *unlocked* on exit.
- *
- * Results:
- * If the copy is successful, KERN_SUCCESS is returned.
- * A new object that represents the copied virtual
- * memory is returned in a parameter (*_result_object).
- * If the return value indicates an error, this parameter
- * is not valid.
+ * Move any resident pages in the specified range to the inactive queue. If kill_page is set,
+ * we also clear the modified status of the page and "forget" any changes that have been made
+ * to the page.
*/
-static kern_return_t
-vm_object_copy_call(
- vm_object_t src_object,
- vm_object_offset_t src_offset,
+
+__private_extern__ void
+vm_object_deactivate_pages(
+ vm_object_t object,
+ vm_object_offset_t offset,
vm_object_size_t size,
- vm_object_t *_result_object) /* OUT */
+ boolean_t kill_page,
+ boolean_t reusable_page,
+ struct pmap *pmap,
+ vm_map_offset_t pmap_offset)
{
- kern_return_t kr;
- vm_object_t copy;
- boolean_t check_ready = FALSE;
- uint32_t try_failed_count = 0;
-
- /*
- * If a copy is already in progress, wait and retry.
- *
- * XXX
- * Consider making this call interruptable, as Mike
- * intended it to be.
- *
- * XXXO
- * Need a counter or version or something to allow
- * us to use the copy that the currently requesting
- * thread is obtaining -- is it worth adding to the
- * vm object structure? Depends how common this case it.
- */
- copy_call_count++;
- while (vm_object_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL)) {
- vm_object_sleep(src_object, VM_OBJECT_EVENT_COPY_CALL,
- THREAD_UNINT);
- copy_call_restart_count++;
- }
+ vm_object_size_t length;
+ boolean_t all_reusable;
+ pmap_flush_context pmap_flush_context_storage;
/*
- * Indicate (for the benefit of memory_object_create_copy)
- * that we want a copy for src_object. (Note that we cannot
- * do a real assert_wait before calling memory_object_copy,
- * so we simply set the flag.)
+ * We break the range up into chunks and do one chunk at a time. This is for
+ * efficiency and performance while handling the shadow chains and the locks.
+ * The deactivate_a_chunk() function returns how much of the range it processed.
+ * We keep calling this routine until the given size is exhausted.
*/
- vm_object_set_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL);
- vm_object_unlock(src_object);
+ all_reusable = FALSE;
+#if 11
/*
- * Ask the memory manager to give us a memory object
- * which represents a copy of the src object.
- * The memory manager may give us a memory object
- * which we already have, or it may give us a
- * new memory object. This memory object will arrive
- * via memory_object_create_copy.
+ * For the sake of accurate "reusable" pmap stats, we need
+ * to tell pmap about each page that is no longer "reusable",
+ * so we can't do the "all_reusable" optimization.
*/
+#else
+ if (reusable_page &&
+ object->internal &&
+ object->vo_size != 0 &&
+ object->vo_size == size &&
+ object->reusable_page_count == 0) {
+ all_reusable = TRUE;
+ reusable_page = FALSE;
+ }
+#endif
- kr = KERN_FAILURE; /* XXX need to change memory_object.defs */
- if (kr != KERN_SUCCESS) {
- return kr;
+ if ((reusable_page || all_reusable) && object->all_reusable) {
+ /* This means MADV_FREE_REUSABLE has been called twice, which
+ * is probably illegal. */
+ return;
}
- /*
- * Wait for the copy to arrive.
- */
- vm_object_lock(src_object);
- while (vm_object_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL)) {
- vm_object_sleep(src_object, VM_OBJECT_EVENT_COPY_CALL,
- THREAD_UNINT);
- copy_call_sleep_count++;
+ pmap_flush_context_init(&pmap_flush_context_storage);
+
+ while (size) {
+ length = deactivate_a_chunk(object, offset, size, kill_page, reusable_page, all_reusable, &pmap_flush_context_storage, pmap, pmap_offset);
+
+ size -= length;
+ offset += length;
+ pmap_offset += length;
}
-Retry:
- assert(src_object->copy != VM_OBJECT_NULL);
- copy = src_object->copy;
- if (!vm_object_lock_try(copy)) {
- vm_object_unlock(src_object);
+ pmap_flush(&pmap_flush_context_storage);
- try_failed_count++;
- mutex_pause(try_failed_count); /* wait a bit */
+ if (all_reusable) {
+ if (!object->all_reusable) {
+ unsigned int reusable;
- vm_object_lock(src_object);
- goto Retry;
+ object->all_reusable = TRUE;
+ assert(object->reusable_page_count == 0);
+ /* update global stats */
+ reusable = object->resident_page_count;
+ OSAddAtomic(reusable,
+ &vm_page_stats_reusable.reusable_count);
+ vm_page_stats_reusable.reusable += reusable;
+ vm_page_stats_reusable.all_reusable_calls++;
+ }
+ } else if (reusable_page) {
+ vm_page_stats_reusable.partial_reusable_calls++;
}
- if (copy->size < src_offset+size)
- copy->size = src_offset+size;
+}
- if (!copy->pager_ready)
- check_ready = TRUE;
+void
+vm_object_reuse_pages(
+ vm_object_t object,
+ vm_object_offset_t start_offset,
+ vm_object_offset_t end_offset,
+ boolean_t allow_partial_reuse)
+{
+ vm_object_offset_t cur_offset;
+ vm_page_t m;
+ unsigned int reused, reusable;
- /*
- * Return the copy.
- */
- *_result_object = copy;
- vm_object_unlock(copy);
- vm_object_unlock(src_object);
+#define VM_OBJECT_REUSE_PAGE(object, m, reused) \
+ MACRO_BEGIN \
+ if ((m) != VM_PAGE_NULL && \
+ (m)->reusable) { \
+ assert((object)->reusable_page_count <= \
+ (object)->resident_page_count); \
+ assert((object)->reusable_page_count > 0); \
+ (object)->reusable_page_count--; \
+ (m)->reusable = FALSE; \
+ (reused)++; \
+ /* \
+ * Tell pmap that this page is no longer \
+ * "reusable", to update the "reusable" stats \
+ * for all the pmaps that have mapped this \
+ * page. \
+ */ \
+ pmap_clear_refmod_options(VM_PAGE_GET_PHYS_PAGE((m)), \
+ 0, /* refmod */ \
+ (PMAP_OPTIONS_CLEAR_REUSABLE \
+ | PMAP_OPTIONS_NOFLUSH), \
+ NULL); \
+ } \
+ MACRO_END
- /* Wait for the copy to be ready. */
- if (check_ready == TRUE) {
- vm_object_lock(copy);
- while (!copy->pager_ready) {
- vm_object_sleep(copy, VM_OBJECT_EVENT_PAGER_READY, THREAD_UNINT);
+ reused = 0;
+ reusable = 0;
+
+ vm_object_lock_assert_exclusive(object);
+
+ if (object->all_reusable) {
+ panic("object %p all_reusable: can't update pmap stats\n",
+ object);
+ assert(object->reusable_page_count == 0);
+ object->all_reusable = FALSE;
+ if (end_offset - start_offset == object->vo_size ||
+ !allow_partial_reuse) {
+ vm_page_stats_reusable.all_reuse_calls++;
+ reused = object->resident_page_count;
+ } else {
+ vm_page_stats_reusable.partial_reuse_calls++;
+ vm_page_queue_iterate(&object->memq, m, vm_page_t, listq) {
+ if (m->offset < start_offset ||
+ m->offset >= end_offset) {
+ m->reusable = TRUE;
+ object->reusable_page_count++;
+ assert(object->resident_page_count >= object->reusable_page_count);
+ continue;
+ } else {
+ assert(!m->reusable);
+ reused++;
+ }
+ }
+ }
+ } else if (object->resident_page_count >
+ ((end_offset - start_offset) >> PAGE_SHIFT)) {
+ vm_page_stats_reusable.partial_reuse_calls++;
+ for (cur_offset = start_offset;
+ cur_offset < end_offset;
+ cur_offset += PAGE_SIZE_64) {
+ if (object->reusable_page_count == 0) {
+ break;
+ }
+ m = vm_page_lookup(object, cur_offset);
+ VM_OBJECT_REUSE_PAGE(object, m, reused);
+ }
+ } else {
+ vm_page_stats_reusable.partial_reuse_calls++;
+ vm_page_queue_iterate(&object->memq, m, vm_page_t, listq) {
+ if (object->reusable_page_count == 0) {
+ break;
+ }
+ if (m->offset < start_offset ||
+ m->offset >= end_offset) {
+ continue;
+ }
+ VM_OBJECT_REUSE_PAGE(object, m, reused);
}
- vm_object_unlock(copy);
}
- return KERN_SUCCESS;
+ /* update global stats */
+ OSAddAtomic(reusable-reused, &vm_page_stats_reusable.reusable_count);
+ vm_page_stats_reusable.reused += reused;
+ vm_page_stats_reusable.reusable += reusable;
}
-static int copy_delayed_lock_collisions = 0;
-static int copy_delayed_max_collisions = 0;
-static int copy_delayed_lock_contention = 0;
-static int copy_delayed_protect_iterate = 0;
-
/*
- * Routine: vm_object_copy_delayed [internal]
+ * Routine: vm_object_pmap_protect
*
- * Description:
- * Copy the specified virtual memory object, using
- * the asymmetric copy-on-write algorithm.
+ * Purpose:
+ * Reduces the permission for all physical
+ * pages in the specified object range.
*
- * In/out conditions:
- * The src_object must be locked on entry. It will be unlocked
- * on exit - so the caller must also hold a reference to it.
+ * If removing write permission only, it is
+ * sufficient to protect only the pages in
+ * the top-level object; only those pages may
+ * have write permission.
*
- * This routine will not block waiting for user-generated
- * events. It is not interruptible.
+ * If removing all access, we must follow the
+ * shadow chain from the top-level object to
+ * remove access to all pages in shadowed objects.
+ *
+ * The object must *not* be locked. The object must
+ * be temporary/internal.
+ *
+ * If pmap is not NULL, this routine assumes that
+ * the only mappings for the pages are in that
+ * pmap.
*/
-__private_extern__ vm_object_t
-vm_object_copy_delayed(
- vm_object_t src_object,
- vm_object_offset_t src_offset,
- vm_object_size_t size,
- boolean_t src_object_shared)
+
+__private_extern__ void
+vm_object_pmap_protect(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ pmap_t pmap,
+ vm_map_offset_t pmap_start,
+ vm_prot_t prot)
{
- vm_object_t new_copy = VM_OBJECT_NULL;
- vm_object_t old_copy;
- vm_page_t p;
- vm_object_size_t copy_size = src_offset + size;
+ vm_object_pmap_protect_options(object, offset, size,
+ pmap, pmap_start, prot, 0);
+}
+__private_extern__ void
+vm_object_pmap_protect_options(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ pmap_t pmap,
+ vm_map_offset_t pmap_start,
+ vm_prot_t prot,
+ int options)
+{
+ pmap_flush_context pmap_flush_context_storage;
+ boolean_t delayed_pmap_flush = FALSE;
- int collisions = 0;
- /*
- * The user-level memory manager wants to see all of the changes
- * to this object, but it has promised not to make any changes on
- * its own.
- *
- * Perform an asymmetric copy-on-write, as follows:
- * Create a new object, called a "copy object" to hold
- * pages modified by the new mapping (i.e., the copy,
- * not the original mapping).
- * Record the original object as the backing object for
- * the copy object. If the original mapping does not
- * change a page, it may be used read-only by the copy.
- * Record the copy object in the original object.
- * When the original mapping causes a page to be modified,
- * it must be copied to a new page that is "pushed" to
- * the copy object.
- * Mark the new mapping (the copy object) copy-on-write.
- * This makes the copy object itself read-only, allowing
- * it to be reused if the original mapping makes no
- * changes, and simplifying the synchronization required
- * in the "push" operation described above.
- *
- * The copy-on-write is said to be assymetric because the original
- * object is *not* marked copy-on-write. A copied page is pushed
- * to the copy object, regardless which party attempted to modify
- * the page.
- *
- * Repeated asymmetric copy operations may be done. If the
- * original object has not been changed since the last copy, its
- * copy object can be reused. Otherwise, a new copy object can be
- * inserted between the original object and its previous copy
- * object. Since any copy object is read-only, this cannot affect
- * affect the contents of the previous copy object.
- *
- * Note that a copy object is higher in the object tree than the
- * original object; therefore, use of the copy object recorded in
- * the original object must be done carefully, to avoid deadlock.
- */
+ if (object == VM_OBJECT_NULL)
+ return;
+ size = vm_object_round_page(size);
+ offset = vm_object_trunc_page(offset);
- Retry:
-
- /*
- * Wait for paging in progress.
- */
- if (!src_object->true_share &&
- (src_object->paging_in_progress != 0 ||
- src_object->activity_in_progress != 0)) {
- if (src_object_shared == TRUE) {
- vm_object_unlock(src_object);
- vm_object_lock(src_object);
- src_object_shared = FALSE;
- goto Retry;
- }
- vm_object_paging_wait(src_object, THREAD_UNINT);
- }
- /*
- * See whether we can reuse the result of a previous
- * copy operation.
- */
+ vm_object_lock(object);
- old_copy = src_object->copy;
- if (old_copy != VM_OBJECT_NULL) {
- int lock_granted;
+ if (object->phys_contiguous) {
+ if (pmap != NULL) {
+ vm_object_unlock(object);
+ pmap_protect_options(pmap,
+ pmap_start,
+ pmap_start + size,
+ prot,
+ options & ~PMAP_OPTIONS_NOFLUSH,
+ NULL);
+ } else {
+ vm_object_offset_t phys_start, phys_end, phys_addr;
- /*
- * Try to get the locks (out of order)
- */
- if (src_object_shared == TRUE)
- lock_granted = vm_object_lock_try_shared(old_copy);
- else
- lock_granted = vm_object_lock_try(old_copy);
+ phys_start = object->vo_shadow_offset + offset;
+ phys_end = phys_start + size;
+ assert(phys_start <= phys_end);
+ assert(phys_end <= object->vo_shadow_offset + object->vo_size);
+ vm_object_unlock(object);
- if (!lock_granted) {
- vm_object_unlock(src_object);
+ pmap_flush_context_init(&pmap_flush_context_storage);
+ delayed_pmap_flush = FALSE;
- if (collisions++ == 0)
- copy_delayed_lock_contention++;
- mutex_pause(collisions);
+ for (phys_addr = phys_start;
+ phys_addr < phys_end;
+ phys_addr += PAGE_SIZE_64) {
+ pmap_page_protect_options(
+ (ppnum_t) (phys_addr >> PAGE_SHIFT),
+ prot,
+ options | PMAP_OPTIONS_NOFLUSH,
+ (void *)&pmap_flush_context_storage);
+ delayed_pmap_flush = TRUE;
+ }
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
+ }
+ return;
+ }
- /* Heisenberg Rules */
- copy_delayed_lock_collisions++;
+ assert(object->internal);
- if (collisions > copy_delayed_max_collisions)
- copy_delayed_max_collisions = collisions;
+ while (TRUE) {
+ if (ptoa_64(object->resident_page_count) > size/2 && pmap != PMAP_NULL) {
+ vm_object_unlock(object);
+ pmap_protect_options(pmap, pmap_start, pmap_start + size, prot,
+ options & ~PMAP_OPTIONS_NOFLUSH, NULL);
+ return;
+ }
- if (src_object_shared == TRUE)
- vm_object_lock_shared(src_object);
- else
- vm_object_lock(src_object);
+ pmap_flush_context_init(&pmap_flush_context_storage);
+ delayed_pmap_flush = FALSE;
- goto Retry;
- }
+ /*
+ * if we are doing large ranges with respect to resident
+ * page count then we should interate over pages otherwise
+ * inverse page look-up will be faster
+ */
+ if (ptoa_64(object->resident_page_count / 4) < size) {
+ vm_page_t p;
+ vm_object_offset_t end;
- /*
- * Determine whether the old copy object has
- * been modified.
- */
+ end = offset + size;
- if (old_copy->resident_page_count == 0 &&
- !old_copy->pager_created) {
- /*
- * It has not been modified.
- *
- * Return another reference to
- * the existing copy-object if
- * we can safely grow it (if
- * needed).
- */
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+ if (!p->fictitious && (offset <= p->offset) && (p->offset < end)) {
+ vm_map_offset_t start;
+
+ start = pmap_start + p->offset - offset;
+
+ if (pmap != PMAP_NULL)
+ pmap_protect_options(
+ pmap,
+ start,
+ start + PAGE_SIZE_64,
+ prot,
+ options | PMAP_OPTIONS_NOFLUSH,
+ &pmap_flush_context_storage);
+ else
+ pmap_page_protect_options(
+ VM_PAGE_GET_PHYS_PAGE(p),
+ prot,
+ options | PMAP_OPTIONS_NOFLUSH,
+ &pmap_flush_context_storage);
+ delayed_pmap_flush = TRUE;
+ }
+ }
- if (old_copy->size < copy_size) {
- if (src_object_shared == TRUE) {
- vm_object_unlock(old_copy);
- vm_object_unlock(src_object);
-
- vm_object_lock(src_object);
- src_object_shared = FALSE;
- goto Retry;
- }
- /*
- * We can't perform a delayed copy if any of the
- * pages in the extended range are wired (because
- * we can't safely take write permission away from
- * wired pages). If the pages aren't wired, then
- * go ahead and protect them.
- */
- copy_delayed_protect_iterate++;
+ } else {
+ vm_page_t p;
+ vm_object_offset_t end;
+ vm_object_offset_t target_off;
- queue_iterate(&src_object->memq, p, vm_page_t, listq) {
- if (!p->fictitious &&
- p->offset >= old_copy->size &&
- p->offset < copy_size) {
- if (VM_PAGE_WIRED(p)) {
- vm_object_unlock(old_copy);
- vm_object_unlock(src_object);
+ end = offset + size;
- if (new_copy != VM_OBJECT_NULL) {
- vm_object_unlock(new_copy);
- vm_object_deallocate(new_copy);
- }
+ for (target_off = offset;
+ target_off < end; target_off += PAGE_SIZE) {
- return VM_OBJECT_NULL;
- } else {
- pmap_page_protect(p->phys_page,
- (VM_PROT_ALL & ~VM_PROT_WRITE));
- }
- }
- }
- old_copy->size = copy_size;
- }
- if (src_object_shared == TRUE)
- vm_object_reference_shared(old_copy);
- else
- vm_object_reference_locked(old_copy);
- vm_object_unlock(old_copy);
- vm_object_unlock(src_object);
+ p = vm_page_lookup(object, target_off);
- if (new_copy != VM_OBJECT_NULL) {
- vm_object_unlock(new_copy);
- vm_object_deallocate(new_copy);
- }
- return(old_copy);
+ if (p != VM_PAGE_NULL) {
+ vm_object_offset_t start;
+
+ start = pmap_start + (p->offset - offset);
+
+ if (pmap != PMAP_NULL)
+ pmap_protect_options(
+ pmap,
+ start,
+ start + PAGE_SIZE_64,
+ prot,
+ options | PMAP_OPTIONS_NOFLUSH,
+ &pmap_flush_context_storage);
+ else
+ pmap_page_protect_options(
+ VM_PAGE_GET_PHYS_PAGE(p),
+ prot,
+ options | PMAP_OPTIONS_NOFLUSH,
+ &pmap_flush_context_storage);
+ delayed_pmap_flush = TRUE;
+ }
}
-
-
+ }
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
+ if (prot == VM_PROT_NONE) {
/*
- * Adjust the size argument so that the newly-created
- * copy object will be large enough to back either the
- * old copy object or the new mapping.
+ * Must follow shadow chain to remove access
+ * to pages in shadowed objects.
*/
- if (old_copy->size > copy_size)
- copy_size = old_copy->size;
-
- if (new_copy == VM_OBJECT_NULL) {
- vm_object_unlock(old_copy);
- vm_object_unlock(src_object);
- new_copy = vm_object_allocate(copy_size);
- vm_object_lock(src_object);
- vm_object_lock(new_copy);
+ vm_object_t next_object;
- src_object_shared = FALSE;
- goto Retry;
+ next_object = object->shadow;
+ if (next_object != VM_OBJECT_NULL) {
+ offset += object->vo_shadow_offset;
+ vm_object_lock(next_object);
+ vm_object_unlock(object);
+ object = next_object;
}
- new_copy->size = copy_size;
-
+ else {
+ /*
+ * End of chain - we are done.
+ */
+ break;
+ }
+ }
+ else {
/*
- * The copy-object is always made large enough to
- * completely shadow the original object, since
- * it may have several users who want to shadow
- * the original object at different points.
+ * Pages in shadowed objects may never have
+ * write permission - we may stop here.
*/
+ break;
+ }
+ }
- assert((old_copy->shadow == src_object) &&
- (old_copy->shadow_offset == (vm_object_offset_t) 0));
+ vm_object_unlock(object);
+}
- } else if (new_copy == VM_OBJECT_NULL) {
- vm_object_unlock(src_object);
- new_copy = vm_object_allocate(copy_size);
- vm_object_lock(src_object);
- vm_object_lock(new_copy);
+/*
+ * Routine: vm_object_copy_slowly
+ *
+ * Description:
+ * Copy the specified range of the source
+ * virtual memory object without using
+ * protection-based optimizations (such
+ * as copy-on-write). The pages in the
+ * region are actually copied.
+ *
+ * In/out conditions:
+ * The caller must hold a reference and a lock
+ * for the source virtual memory object. The source
+ * object will be returned *unlocked*.
+ *
+ * Results:
+ * If the copy is completed successfully, KERN_SUCCESS is
+ * returned. If the caller asserted the interruptible
+ * argument, and an interruption occurred while waiting
+ * for a user-generated event, MACH_SEND_INTERRUPTED is
+ * returned. Other values may be returned to indicate
+ * hard errors during the copy operation.
+ *
+ * A new virtual memory object is returned in a
+ * parameter (_result_object). The contents of this
+ * new object, starting at a zero offset, are a copy
+ * of the source memory region. In the event of
+ * an error, this parameter will contain the value
+ * VM_OBJECT_NULL.
+ */
+__private_extern__ kern_return_t
+vm_object_copy_slowly(
+ vm_object_t src_object,
+ vm_object_offset_t src_offset,
+ vm_object_size_t size,
+ boolean_t interruptible,
+ vm_object_t *_result_object) /* OUT */
+{
+ vm_object_t new_object;
+ vm_object_offset_t new_offset;
- src_object_shared = FALSE;
- goto Retry;
+ struct vm_object_fault_info fault_info;
+
+ XPR(XPR_VM_OBJECT, "v_o_c_slowly obj 0x%x off 0x%x size 0x%x\n",
+ src_object, src_offset, size, 0, 0);
+
+ if (size == 0) {
+ vm_object_unlock(src_object);
+ *_result_object = VM_OBJECT_NULL;
+ return(KERN_INVALID_ARGUMENT);
}
/*
- * We now have the src object locked, and the new copy object
- * allocated and locked (and potentially the old copy locked).
- * Before we go any further, make sure we can still perform
- * a delayed copy, as the situation may have changed.
- *
- * Specifically, we can't perform a delayed copy if any of the
- * pages in the range are wired (because we can't safely take
- * write permission away from wired pages). If the pages aren't
- * wired, then go ahead and protect them.
+ * Prevent destruction of the source object while we copy.
*/
- copy_delayed_protect_iterate++;
- queue_iterate(&src_object->memq, p, vm_page_t, listq) {
- if (!p->fictitious && p->offset < copy_size) {
- if (VM_PAGE_WIRED(p)) {
- if (old_copy)
- vm_object_unlock(old_copy);
- vm_object_unlock(src_object);
- vm_object_unlock(new_copy);
- vm_object_deallocate(new_copy);
- return VM_OBJECT_NULL;
- } else {
- pmap_page_protect(p->phys_page,
- (VM_PROT_ALL & ~VM_PROT_WRITE));
- }
- }
- }
- if (old_copy != VM_OBJECT_NULL) {
- /*
- * Make the old copy-object shadow the new one.
- * It will receive no more pages from the original
- * object.
- */
-
- /* remove ref. from old_copy */
- vm_object_lock_assert_exclusive(src_object);
- src_object->ref_count--;
- assert(src_object->ref_count > 0);
- vm_object_lock_assert_exclusive(old_copy);
- old_copy->shadow = new_copy;
- vm_object_lock_assert_exclusive(new_copy);
- assert(new_copy->ref_count > 0);
- new_copy->ref_count++; /* for old_copy->shadow ref. */
-
-#if TASK_SWAPPER
- if (old_copy->res_count) {
- VM_OBJ_RES_INCR(new_copy);
- VM_OBJ_RES_DECR(src_object);
- }
-#endif
-
- vm_object_unlock(old_copy); /* done with old_copy */
- }
+ vm_object_reference_locked(src_object);
+ vm_object_unlock(src_object);
/*
- * Point the new copy at the existing object.
+ * Create a new object to hold the copied pages.
+ * A few notes:
+ * We fill the new object starting at offset 0,
+ * regardless of the input offset.
+ * We don't bother to lock the new object within
+ * this routine, since we have the only reference.
*/
- vm_object_lock_assert_exclusive(new_copy);
- new_copy->shadow = src_object;
- new_copy->shadow_offset = 0;
- new_copy->shadowed = TRUE; /* caller must set needs_copy */
-
- vm_object_lock_assert_exclusive(src_object);
- vm_object_reference_locked(src_object);
- src_object->copy = new_copy;
- vm_object_unlock(src_object);
- vm_object_unlock(new_copy);
-
- XPR(XPR_VM_OBJECT,
- "vm_object_copy_delayed: used copy object %X for source %X\n",
- new_copy, src_object, 0, 0, 0);
- return new_copy;
-}
+ new_object = vm_object_allocate(size);
+ new_offset = 0;
-/*
- * Routine: vm_object_copy_strategically
- *
- * Purpose:
- * Perform a copy according to the source object's
- * declared strategy. This operation may block,
- * and may be interrupted.
- */
-__private_extern__ kern_return_t
-vm_object_copy_strategically(
- register vm_object_t src_object,
- vm_object_offset_t src_offset,
- vm_object_size_t size,
- vm_object_t *dst_object, /* OUT */
- vm_object_offset_t *dst_offset, /* OUT */
- boolean_t *dst_needs_copy) /* OUT */
-{
- boolean_t result;
- boolean_t interruptible = THREAD_ABORTSAFE; /* XXX */
- boolean_t object_lock_shared = FALSE;
- memory_object_copy_strategy_t copy_strategy;
+ assert(size == trunc_page_64(size)); /* Will the loop terminate? */
- assert(src_object != VM_OBJECT_NULL);
+ fault_info.interruptible = interruptible;
+ fault_info.behavior = VM_BEHAVIOR_SEQUENTIAL;
+ fault_info.user_tag = 0;
+ fault_info.pmap_options = 0;
+ fault_info.lo_offset = src_offset;
+ fault_info.hi_offset = src_offset + size;
+ fault_info.no_cache = FALSE;
+ fault_info.stealth = TRUE;
+ fault_info.io_sync = FALSE;
+ fault_info.cs_bypass = FALSE;
+ fault_info.mark_zf_absent = FALSE;
+ fault_info.batch_pmap_op = FALSE;
- copy_strategy = src_object->copy_strategy;
+ for ( ;
+ size != 0 ;
+ src_offset += PAGE_SIZE_64,
+ new_offset += PAGE_SIZE_64, size -= PAGE_SIZE_64
+ ) {
+ vm_page_t new_page;
+ vm_fault_return_t result;
- if (copy_strategy == MEMORY_OBJECT_COPY_DELAY) {
- vm_object_lock_shared(src_object);
- object_lock_shared = TRUE;
- } else
- vm_object_lock(src_object);
+ vm_object_lock(new_object);
- /*
- * The copy strategy is only valid if the memory manager
- * is "ready". Internal objects are always ready.
- */
+ while ((new_page = vm_page_alloc(new_object, new_offset))
+ == VM_PAGE_NULL) {
- while (!src_object->internal && !src_object->pager_ready) {
- wait_result_t wait_result;
+ vm_object_unlock(new_object);
- if (object_lock_shared == TRUE) {
- vm_object_unlock(src_object);
- vm_object_lock(src_object);
- object_lock_shared = FALSE;
- continue;
- }
- wait_result = vm_object_sleep( src_object,
- VM_OBJECT_EVENT_PAGER_READY,
- interruptible);
- if (wait_result != THREAD_AWAKENED) {
- vm_object_unlock(src_object);
- *dst_object = VM_OBJECT_NULL;
- *dst_offset = 0;
- *dst_needs_copy = FALSE;
- return(MACH_SEND_INTERRUPTED);
+ if (!vm_page_wait(interruptible)) {
+ vm_object_deallocate(new_object);
+ vm_object_deallocate(src_object);
+ *_result_object = VM_OBJECT_NULL;
+ return(MACH_SEND_INTERRUPTED);
+ }
+ vm_object_lock(new_object);
}
- }
-
- /*
- * Use the appropriate copy strategy.
- */
+ vm_object_unlock(new_object);
- switch (copy_strategy) {
- case MEMORY_OBJECT_COPY_DELAY:
- *dst_object = vm_object_copy_delayed(src_object,
- src_offset, size, object_lock_shared);
- if (*dst_object != VM_OBJECT_NULL) {
- *dst_offset = src_offset;
- *dst_needs_copy = TRUE;
- result = KERN_SUCCESS;
- break;
- }
- vm_object_lock(src_object);
- /* fall thru when delayed copy not allowed */
+ do {
+ vm_prot_t prot = VM_PROT_READ;
+ vm_page_t _result_page;
+ vm_page_t top_page;
+ vm_page_t result_page;
+ kern_return_t error_code;
+ vm_object_t result_page_object;
- case MEMORY_OBJECT_COPY_NONE:
- result = vm_object_copy_slowly(src_object, src_offset, size,
- interruptible, dst_object);
- if (result == KERN_SUCCESS) {
- *dst_offset = 0;
- *dst_needs_copy = FALSE;
- }
- break;
- case MEMORY_OBJECT_COPY_CALL:
- result = vm_object_copy_call(src_object, src_offset, size,
- dst_object);
- if (result == KERN_SUCCESS) {
- *dst_offset = src_offset;
- *dst_needs_copy = TRUE;
- }
- break;
+ vm_object_lock(src_object);
- case MEMORY_OBJECT_COPY_SYMMETRIC:
- XPR(XPR_VM_OBJECT, "v_o_c_strategically obj 0x%x off 0x%x size 0x%x\n", src_object, src_offset, size, 0, 0);
- vm_object_unlock(src_object);
- result = KERN_MEMORY_RESTART_COPY;
- break;
+ if (src_object->internal &&
+ src_object->shadow == VM_OBJECT_NULL &&
+ (vm_page_lookup(src_object,
+ src_offset) == VM_PAGE_NULL) &&
+ (src_object->pager == NULL ||
+ (VM_COMPRESSOR_PAGER_STATE_GET(src_object,
+ src_offset) ==
+ VM_EXTERNAL_STATE_ABSENT))) {
+ /*
+ * This page is neither resident nor compressed
+ * and there's no shadow object below
+ * "src_object", so this page is really missing.
+ * There's no need to zero-fill it just to copy
+ * it: let's leave it missing in "new_object"
+ * and get zero-filled on demand.
+ */
+ vm_object_unlock(src_object);
+ /* free the unused "new_page"... */
+ vm_object_lock(new_object);
+ VM_PAGE_FREE(new_page);
+ new_page = VM_PAGE_NULL;
+ vm_object_unlock(new_object);
+ /* ...and go to next page in "src_object" */
+ result = VM_FAULT_SUCCESS;
+ break;
+ }
- default:
- panic("copy_strategically: bad strategy");
- result = KERN_INVALID_ARGUMENT;
- }
- return(result);
-}
+ vm_object_paging_begin(src_object);
-/*
- * vm_object_shadow:
- *
- * Create a new object which is backed by the
- * specified existing object range. The source
- * object reference is deallocated.
- *
- * The new object and offset into that object
- * are returned in the source parameters.
- */
-boolean_t vm_object_shadow_check = FALSE;
+ if (size > (vm_size_t) -1) {
+ /* 32-bit overflow */
+ fault_info.cluster_size = (vm_size_t) (0 - PAGE_SIZE);
+ } else {
+ fault_info.cluster_size = (vm_size_t) size;
+ assert(fault_info.cluster_size == size);
+ }
-__private_extern__ boolean_t
-vm_object_shadow(
- vm_object_t *object, /* IN/OUT */
- vm_object_offset_t *offset, /* IN/OUT */
- vm_object_size_t length)
-{
- register vm_object_t source;
- register vm_object_t result;
+ XPR(XPR_VM_FAULT,"vm_object_copy_slowly -> vm_fault_page",0,0,0,0,0);
+ _result_page = VM_PAGE_NULL;
+ result = vm_fault_page(src_object, src_offset,
+ VM_PROT_READ, FALSE,
+ FALSE, /* page not looked up */
+ &prot, &_result_page, &top_page,
+ (int *)0,
+ &error_code, FALSE, FALSE, &fault_info);
- source = *object;
-#if 0
- /*
- * XXX FBDP
- * This assertion is valid but it gets triggered by Rosetta for example
- * due to a combination of vm_remap() that changes a VM object's
- * copy_strategy from SYMMETRIC to DELAY and vm_protect(VM_PROT_COPY)
- * that then sets "needs_copy" on its map entry. This creates a
- * mapping situation that VM should never see and doesn't know how to
- * handle.
- * It's not clear if this can create any real problem but we should
- * look into fixing this, probably by having vm_protect(VM_PROT_COPY)
- * do more than just set "needs_copy" to handle the copy-on-write...
- * In the meantime, let's disable the assertion.
- */
- assert(source->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC);
-#endif
+ switch(result) {
+ case VM_FAULT_SUCCESS:
+ result_page = _result_page;
+ result_page_object = VM_PAGE_OBJECT(result_page);
- /*
- * Determine if we really need a shadow.
- */
+ /*
+ * Copy the page to the new object.
+ *
+ * POLICY DECISION:
+ * If result_page is clean,
+ * we could steal it instead
+ * of copying.
+ */
- if (vm_object_shadow_check && source->ref_count == 1 &&
- (source->shadow == VM_OBJECT_NULL ||
- source->shadow->copy == VM_OBJECT_NULL))
- {
- source->shadowed = FALSE;
- return FALSE;
- }
+ vm_page_copy(result_page, new_page);
+ vm_object_unlock(result_page_object);
- /*
- * Allocate a new object with the given length
- */
+ /*
+ * Let go of both pages (make them
+ * not busy, perform wakeup, activate).
+ */
+ vm_object_lock(new_object);
+ SET_PAGE_DIRTY(new_page, FALSE);
+ PAGE_WAKEUP_DONE(new_page);
+ vm_object_unlock(new_object);
- if ((result = vm_object_allocate(length)) == VM_OBJECT_NULL)
- panic("vm_object_shadow: no object for shadowing");
+ vm_object_lock(result_page_object);
+ PAGE_WAKEUP_DONE(result_page);
- /*
- * The new object shadows the source object, adding
- * a reference to it. Our caller changes his reference
- * to point to the new object, removing a reference to
- * the source object. Net result: no change of reference
- * count.
- */
- result->shadow = source;
-
- /*
- * Store the offset into the source object,
- * and fix up the offset into the new object.
- */
+ vm_page_lockspin_queues();
+ if ((result_page->vm_page_q_state == VM_PAGE_ON_SPECULATIVE_Q) ||
+ (result_page->vm_page_q_state == VM_PAGE_NOT_ON_Q)) {
+ vm_page_activate(result_page);
+ }
+ vm_page_activate(new_page);
+ vm_page_unlock_queues();
+
+ /*
+ * Release paging references and
+ * top-level placeholder page, if any.
+ */
+
+ vm_fault_cleanup(result_page_object,
+ top_page);
+
+ break;
+
+ case VM_FAULT_RETRY:
+ break;
+
+ case VM_FAULT_MEMORY_SHORTAGE:
+ if (vm_page_wait(interruptible))
+ break;
+ /* fall thru */
+
+ case VM_FAULT_INTERRUPTED:
+ vm_object_lock(new_object);
+ VM_PAGE_FREE(new_page);
+ vm_object_unlock(new_object);
+
+ vm_object_deallocate(new_object);
+ vm_object_deallocate(src_object);
+ *_result_object = VM_OBJECT_NULL;
+ return(MACH_SEND_INTERRUPTED);
+
+ case VM_FAULT_SUCCESS_NO_VM_PAGE:
+ /* success but no VM page: fail */
+ vm_object_paging_end(src_object);
+ vm_object_unlock(src_object);
+ /*FALLTHROUGH*/
+ case VM_FAULT_MEMORY_ERROR:
+ /*
+ * A policy choice:
+ * (a) ignore pages that we can't
+ * copy
+ * (b) return the null object if
+ * any page fails [chosen]
+ */
+
+ vm_object_lock(new_object);
+ VM_PAGE_FREE(new_page);
+ vm_object_unlock(new_object);
+
+ vm_object_deallocate(new_object);
+ vm_object_deallocate(src_object);
+ *_result_object = VM_OBJECT_NULL;
+ return(error_code ? error_code:
+ KERN_MEMORY_ERROR);
- result->shadow_offset = *offset;
+ default:
+ panic("vm_object_copy_slowly: unexpected error"
+ " 0x%x from vm_fault_page()\n", result);
+ }
+ } while (result != VM_FAULT_SUCCESS);
+ }
/*
- * Return the new things
+ * Lose the extra reference, and return our object.
*/
-
- *offset = 0;
- *object = result;
- return TRUE;
+ vm_object_deallocate(src_object);
+ *_result_object = new_object;
+ return(KERN_SUCCESS);
}
/*
- * The relationship between vm_object structures and
- * the memory_object requires careful synchronization.
- *
- * All associations are created by memory_object_create_named
- * for external pagers and vm_object_pager_create for internal
- * objects as follows:
- *
- * pager: the memory_object itself, supplied by
- * the user requesting a mapping (or the kernel,
- * when initializing internal objects); the
- * kernel simulates holding send rights by keeping
- * a port reference;
- *
- * pager_request:
- * the memory object control port,
- * created by the kernel; the kernel holds
- * receive (and ownership) rights to this
- * port, but no other references.
- *
- * When initialization is complete, the "initialized" field
- * is asserted. Other mappings using a particular memory object,
- * and any references to the vm_object gained through the
- * port association must wait for this initialization to occur.
- *
- * In order to allow the memory manager to set attributes before
- * requests (notably virtual copy operations, but also data or
- * unlock requests) are made, a "ready" attribute is made available.
- * Only the memory manager may affect the value of this attribute.
- * Its value does not affect critical kernel functions, such as
- * internal object initialization or destruction. [Furthermore,
- * memory objects created by the kernel are assumed to be ready
- * immediately; the default memory manager need not explicitly
- * set the "ready" attribute.]
- *
- * [Both the "initialized" and "ready" attribute wait conditions
- * use the "pager" field as the wait event.]
- *
- * The port associations can be broken down by any of the
- * following routines:
- * vm_object_terminate:
- * No references to the vm_object remain, and
- * the object cannot (or will not) be cached.
- * This is the normal case, and is done even
- * though one of the other cases has already been
- * done.
- * memory_object_destroy:
- * The memory manager has requested that the
- * kernel relinquish references to the memory
- * object. [The memory manager may not want to
- * destroy the memory object, but may wish to
- * refuse or tear down existing memory mappings.]
- *
- * Each routine that breaks an association must break all of
- * them at once. At some later time, that routine must clear
- * the pager field and release the memory object references.
- * [Furthermore, each routine must cope with the simultaneous
- * or previous operations of the others.]
+ * Routine: vm_object_copy_quickly
*
- * In addition to the lock on the object, the vm_object_hash_lock
- * governs the associations. References gained through the
- * association require use of the hash lock.
+ * Purpose:
+ * Copy the specified range of the source virtual
+ * memory object, if it can be done without waiting
+ * for user-generated events.
*
- * Because the pager field may be cleared spontaneously, it
- * cannot be used to determine whether a memory object has
- * ever been associated with a particular vm_object. [This
- * knowledge is important to the shadow object mechanism.]
- * For this reason, an additional "created" attribute is
- * provided.
+ * Results:
+ * If the copy is successful, the copy is returned in
+ * the arguments; otherwise, the arguments are not
+ * affected.
*
- * During various paging operations, the pager reference found in the
- * vm_object must be valid. To prevent this from being released,
- * (other than being removed, i.e., made null), routines may use
- * the vm_object_paging_begin/end routines [actually, macros].
- * The implementation uses the "paging_in_progress" and "wanted" fields.
- * [Operations that alter the validity of the pager values include the
- * termination routines and vm_object_collapse.]
+ * In/out conditions:
+ * The object should be unlocked on entry and exit.
*/
-
-/*
- * Routine: vm_object_enter
- * Purpose:
- * Find a VM object corresponding to the given
- * pager; if no such object exists, create one,
- * and initialize the pager.
- */
-vm_object_t
-vm_object_enter(
- memory_object_t pager,
- vm_object_size_t size,
- boolean_t internal,
- boolean_t init,
- boolean_t named)
+/*ARGSUSED*/
+__private_extern__ boolean_t
+vm_object_copy_quickly(
+ vm_object_t *_object, /* INOUT */
+ __unused vm_object_offset_t offset, /* IN */
+ __unused vm_object_size_t size, /* IN */
+ boolean_t *_src_needs_copy, /* OUT */
+ boolean_t *_dst_needs_copy) /* OUT */
{
- register vm_object_t object;
- vm_object_t new_object;
- boolean_t must_init;
- vm_object_hash_entry_t entry, new_entry;
- uint32_t try_failed_count = 0;
- lck_mtx_t *lck;
+ vm_object_t object = *_object;
+ memory_object_copy_strategy_t copy_strategy;
- if (pager == MEMORY_OBJECT_NULL)
- return(vm_object_allocate(size));
+ XPR(XPR_VM_OBJECT, "v_o_c_quickly obj 0x%x off 0x%x size 0x%x\n",
+ *_object, offset, size, 0, 0);
+ if (object == VM_OBJECT_NULL) {
+ *_src_needs_copy = FALSE;
+ *_dst_needs_copy = FALSE;
+ return(TRUE);
+ }
- new_object = VM_OBJECT_NULL;
- new_entry = VM_OBJECT_HASH_ENTRY_NULL;
- must_init = init;
+ vm_object_lock(object);
- /*
- * Look for an object associated with this port.
- */
-Retry:
- lck = vm_object_hash_lock_spin(pager);
- do {
- entry = vm_object_hash_lookup(pager, FALSE);
+ copy_strategy = object->copy_strategy;
- if (entry == VM_OBJECT_HASH_ENTRY_NULL) {
- if (new_object == VM_OBJECT_NULL) {
- /*
- * We must unlock to create a new object;
- * if we do so, we must try the lookup again.
- */
- vm_object_hash_unlock(lck);
- assert(new_entry == VM_OBJECT_HASH_ENTRY_NULL);
- new_entry = vm_object_hash_entry_alloc(pager);
- new_object = vm_object_allocate(size);
- lck = vm_object_hash_lock_spin(pager);
- } else {
- /*
- * Lookup failed twice, and we have something
- * to insert; set the object.
- */
- vm_object_hash_insert(new_entry, new_object);
- entry = new_entry;
- new_entry = VM_OBJECT_HASH_ENTRY_NULL;
- new_object = VM_OBJECT_NULL;
- must_init = TRUE;
- }
- } else if (entry->object == VM_OBJECT_NULL) {
- /*
- * If a previous object is being terminated,
- * we must wait for the termination message
- * to be queued (and lookup the entry again).
- */
- entry->waiting = TRUE;
- entry = VM_OBJECT_HASH_ENTRY_NULL;
- assert_wait((event_t) pager, THREAD_UNINT);
- vm_object_hash_unlock(lck);
-
- thread_block(THREAD_CONTINUE_NULL);
- lck = vm_object_hash_lock_spin(pager);
- }
- } while (entry == VM_OBJECT_HASH_ENTRY_NULL);
-
- object = entry->object;
- assert(object != VM_OBJECT_NULL);
-
- if (!must_init) {
- if ( !vm_object_lock_try(object)) {
-
- vm_object_hash_unlock(lck);
-
- try_failed_count++;
- mutex_pause(try_failed_count); /* wait a bit */
- goto Retry;
- }
- assert(!internal || object->internal);
-#if VM_OBJECT_CACHE
- if (object->ref_count == 0) {
- if ( !vm_object_cache_lock_try()) {
-
- vm_object_hash_unlock(lck);
- vm_object_unlock(object);
-
- try_failed_count++;
- mutex_pause(try_failed_count); /* wait a bit */
- goto Retry;
- }
- XPR(XPR_VM_OBJECT_CACHE,
- "vm_object_enter: removing %x from cache, head (%x, %x)\n",
- object,
- vm_object_cached_list.next,
- vm_object_cached_list.prev, 0,0);
- queue_remove(&vm_object_cached_list, object,
- vm_object_t, cached_list);
- vm_object_cached_count--;
-
- vm_object_cache_unlock();
- }
-#endif
- if (named) {
- assert(!object->named);
- object->named = TRUE;
- }
- vm_object_lock_assert_exclusive(object);
- object->ref_count++;
- vm_object_res_reference(object);
-
- vm_object_hash_unlock(lck);
- vm_object_unlock(object);
-
- VM_STAT_INCR(hits);
- } else
- vm_object_hash_unlock(lck);
-
- assert(object->ref_count > 0);
-
- VM_STAT_INCR(lookups);
-
- XPR(XPR_VM_OBJECT,
- "vm_o_enter: pager 0x%x obj 0x%x must_init %d\n",
- pager, object, must_init, 0, 0);
-
- /*
- * If we raced to create a vm_object but lost, let's
- * throw away ours.
- */
-
- if (new_object != VM_OBJECT_NULL)
- vm_object_deallocate(new_object);
-
- if (new_entry != VM_OBJECT_HASH_ENTRY_NULL)
- vm_object_hash_entry_free(new_entry);
-
- if (must_init) {
- memory_object_control_t control;
-
- /*
- * Allocate request port.
- */
-
- control = memory_object_control_allocate(object);
- assert (control != MEMORY_OBJECT_CONTROL_NULL);
-
- vm_object_lock(object);
- assert(object != kernel_object);
+ switch (copy_strategy) {
+ case MEMORY_OBJECT_COPY_SYMMETRIC:
/*
- * Copy the reference we were given.
+ * Symmetric copy strategy.
+ * Make another reference to the object.
+ * Leave object/offset unchanged.
*/
- memory_object_reference(pager);
- object->pager_created = TRUE;
- object->pager = pager;
- object->internal = internal;
- object->pager_trusted = internal;
- if (!internal) {
- /* copy strategy invalid until set by memory manager */
- object->copy_strategy = MEMORY_OBJECT_COPY_INVALID;
- }
- object->pager_control = control;
- object->pager_ready = FALSE;
-
+ vm_object_reference_locked(object);
+ object->shadowed = TRUE;
vm_object_unlock(object);
/*
- * Let the pager know we're using it.
+ * Both source and destination must make
+ * shadows, and the source must be made
+ * read-only if not already.
*/
- (void) memory_object_init(pager,
- object->pager_control,
- PAGE_SIZE);
-
- vm_object_lock(object);
- if (named)
- object->named = TRUE;
- if (internal) {
- object->pager_ready = TRUE;
- vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY);
- }
-
- object->pager_initialized = TRUE;
- vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED);
- } else {
- vm_object_lock(object);
- }
+ *_src_needs_copy = TRUE;
+ *_dst_needs_copy = TRUE;
- /*
- * [At this point, the object must be locked]
- */
+ break;
- /*
- * Wait for the work above to be done by the first
- * thread to map this object.
- */
+ case MEMORY_OBJECT_COPY_DELAY:
+ vm_object_unlock(object);
+ return(FALSE);
- while (!object->pager_initialized) {
- vm_object_sleep(object,
- VM_OBJECT_EVENT_INITIALIZED,
- THREAD_UNINT);
+ default:
+ vm_object_unlock(object);
+ return(FALSE);
}
- vm_object_unlock(object);
-
- XPR(XPR_VM_OBJECT,
- "vm_object_enter: vm_object %x, memory_object %x, internal %d\n",
- object, object->pager, internal, 0,0);
- return(object);
+ return(TRUE);
}
+static int copy_call_count = 0;
+static int copy_call_sleep_count = 0;
+static int copy_call_restart_count = 0;
+
/*
- * Routine: vm_object_pager_create
- * Purpose:
- * Create a memory object for an internal object.
+ * Routine: vm_object_copy_call [internal]
+ *
+ * Description:
+ * Copy the source object (src_object), using the
+ * user-managed copy algorithm.
+ *
* In/out conditions:
- * The object is locked on entry and exit;
- * it may be unlocked within this call.
- * Limitations:
- * Only one thread may be performing a
- * vm_object_pager_create on an object at
- * a time. Presumably, only the pageout
- * daemon will be using this routine.
+ * The source object must be locked on entry. It
+ * will be *unlocked* on exit.
+ *
+ * Results:
+ * If the copy is successful, KERN_SUCCESS is returned.
+ * A new object that represents the copied virtual
+ * memory is returned in a parameter (*_result_object).
+ * If the return value indicates an error, this parameter
+ * is not valid.
*/
-
-void
-vm_object_pager_create(
- register vm_object_t object)
+static kern_return_t
+vm_object_copy_call(
+ vm_object_t src_object,
+ vm_object_offset_t src_offset,
+ vm_object_size_t size,
+ vm_object_t *_result_object) /* OUT */
{
- memory_object_t pager;
- vm_object_hash_entry_t entry;
- lck_mtx_t *lck;
-#if MACH_PAGEMAP
- vm_object_size_t size;
- vm_external_map_t map;
-#endif /* MACH_PAGEMAP */
-
- XPR(XPR_VM_OBJECT, "vm_object_pager_create, object 0x%X\n",
- object, 0,0,0,0);
-
- assert(object != kernel_object);
-
- if (memory_manager_default_check() != KERN_SUCCESS)
- return;
+ kern_return_t kr;
+ vm_object_t copy;
+ boolean_t check_ready = FALSE;
+ uint32_t try_failed_count = 0;
/*
- * Prevent collapse or termination by holding a paging reference
+ * If a copy is already in progress, wait and retry.
+ *
+ * XXX
+ * Consider making this call interruptable, as Mike
+ * intended it to be.
+ *
+ * XXXO
+ * Need a counter or version or something to allow
+ * us to use the copy that the currently requesting
+ * thread is obtaining -- is it worth adding to the
+ * vm object structure? Depends how common this case it.
*/
-
- vm_object_paging_begin(object);
- if (object->pager_created) {
- /*
- * Someone else got to it first...
- * wait for them to finish initializing the ports
- */
- while (!object->pager_initialized) {
- vm_object_sleep(object,
- VM_OBJECT_EVENT_INITIALIZED,
- THREAD_UNINT);
- }
- vm_object_paging_end(object);
- return;
+ copy_call_count++;
+ while (vm_object_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL)) {
+ vm_object_sleep(src_object, VM_OBJECT_EVENT_COPY_CALL,
+ THREAD_UNINT);
+ copy_call_restart_count++;
}
/*
- * Indicate that a memory object has been assigned
- * before dropping the lock, to prevent a race.
+ * Indicate (for the benefit of memory_object_create_copy)
+ * that we want a copy for src_object. (Note that we cannot
+ * do a real assert_wait before calling memory_object_copy,
+ * so we simply set the flag.)
*/
- object->pager_created = TRUE;
- object->paging_offset = 0;
-
-#if MACH_PAGEMAP
- size = object->size;
-#endif /* MACH_PAGEMAP */
- vm_object_unlock(object);
+ vm_object_set_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL);
+ vm_object_unlock(src_object);
-#if MACH_PAGEMAP
- map = vm_external_create(size);
- vm_object_lock(object);
- assert(object->size == size);
- object->existence_map = map;
- vm_object_unlock(object);
-#endif /* MACH_PAGEMAP */
+ /*
+ * Ask the memory manager to give us a memory object
+ * which represents a copy of the src object.
+ * The memory manager may give us a memory object
+ * which we already have, or it may give us a
+ * new memory object. This memory object will arrive
+ * via memory_object_create_copy.
+ */
- if ((uint32_t) object->size != object->size) {
- panic("vm_object_pager_create(): object size 0x%llx >= 4GB\n",
- (uint64_t) object->size);
+ kr = KERN_FAILURE; /* XXX need to change memory_object.defs */
+ if (kr != KERN_SUCCESS) {
+ return kr;
}
/*
- * Create the [internal] pager, and associate it with this object.
- *
- * We make the association here so that vm_object_enter()
- * can look up the object to complete initializing it. No
- * user will ever map this object.
- */
- {
- memory_object_default_t dmm;
-
- /* acquire a reference for the default memory manager */
- dmm = memory_manager_default_reference();
-
- assert(object->temporary);
-
- /* create our new memory object */
- assert((vm_size_t) object->size == object->size);
- (void) memory_object_create(dmm, (vm_size_t) object->size,
- &pager);
-
- memory_object_default_deallocate(dmm);
- }
-
- entry = vm_object_hash_entry_alloc(pager);
-
- lck = vm_object_hash_lock_spin(pager);
- vm_object_hash_insert(entry, object);
- vm_object_hash_unlock(lck);
-
- /*
- * A reference was returned by
- * memory_object_create(), and it is
- * copied by vm_object_enter().
+ * Wait for the copy to arrive.
*/
+ vm_object_lock(src_object);
+ while (vm_object_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL)) {
+ vm_object_sleep(src_object, VM_OBJECT_EVENT_COPY_CALL,
+ THREAD_UNINT);
+ copy_call_sleep_count++;
+ }
+Retry:
+ assert(src_object->copy != VM_OBJECT_NULL);
+ copy = src_object->copy;
+ if (!vm_object_lock_try(copy)) {
+ vm_object_unlock(src_object);
- if (vm_object_enter(pager, object->size, TRUE, TRUE, FALSE) != object)
- panic("vm_object_pager_create: mismatch");
+ try_failed_count++;
+ mutex_pause(try_failed_count); /* wait a bit */
- /*
- * Drop the reference we were passed.
- */
- memory_object_deallocate(pager);
+ vm_object_lock(src_object);
+ goto Retry;
+ }
+ if (copy->vo_size < src_offset+size)
+ copy->vo_size = src_offset+size;
- vm_object_lock(object);
+ if (!copy->pager_ready)
+ check_ready = TRUE;
/*
- * Release the paging reference
+ * Return the copy.
*/
- vm_object_paging_end(object);
-}
-
-/*
- * Routine: vm_object_remove
- * Purpose:
- * Eliminate the pager/object association
- * for this pager.
- * Conditions:
- * The object cache must be locked.
- */
-__private_extern__ void
-vm_object_remove(
- vm_object_t object)
-{
- memory_object_t pager;
-
- if ((pager = object->pager) != MEMORY_OBJECT_NULL) {
- vm_object_hash_entry_t entry;
+ *_result_object = copy;
+ vm_object_unlock(copy);
+ vm_object_unlock(src_object);
- entry = vm_object_hash_lookup(pager, FALSE);
- if (entry != VM_OBJECT_HASH_ENTRY_NULL)
- entry->object = VM_OBJECT_NULL;
+ /* Wait for the copy to be ready. */
+ if (check_ready == TRUE) {
+ vm_object_lock(copy);
+ while (!copy->pager_ready) {
+ vm_object_sleep(copy, VM_OBJECT_EVENT_PAGER_READY, THREAD_UNINT);
+ }
+ vm_object_unlock(copy);
}
+ return KERN_SUCCESS;
}
-/*
- * Global variables for vm_object_collapse():
- *
- * Counts for normal collapses and bypasses.
- * Debugging variables, to watch or disable collapse.
- */
-static long object_collapses = 0;
-static long object_bypasses = 0;
-
-static boolean_t vm_object_collapse_allowed = TRUE;
-static boolean_t vm_object_bypass_allowed = TRUE;
-
-#if MACH_PAGEMAP
-static int vm_external_discarded;
-static int vm_external_collapsed;
-#endif
-
-unsigned long vm_object_collapse_encrypted = 0;
+static int copy_delayed_lock_collisions = 0;
+static int copy_delayed_max_collisions = 0;
+static int copy_delayed_lock_contention = 0;
+static int copy_delayed_protect_iterate = 0;
/*
- * Routine: vm_object_do_collapse
- * Purpose:
- * Collapse an object with the object backing it.
- * Pages in the backing object are moved into the
- * parent, and the backing object is deallocated.
- * Conditions:
- * Both objects and the cache are locked; the page
- * queues are unlocked.
+ * Routine: vm_object_copy_delayed [internal]
+ *
+ * Description:
+ * Copy the specified virtual memory object, using
+ * the asymmetric copy-on-write algorithm.
+ *
+ * In/out conditions:
+ * The src_object must be locked on entry. It will be unlocked
+ * on exit - so the caller must also hold a reference to it.
*
+ * This routine will not block waiting for user-generated
+ * events. It is not interruptible.
*/
-static void
-vm_object_do_collapse(
- vm_object_t object,
- vm_object_t backing_object)
+__private_extern__ vm_object_t
+vm_object_copy_delayed(
+ vm_object_t src_object,
+ vm_object_offset_t src_offset,
+ vm_object_size_t size,
+ boolean_t src_object_shared)
{
- vm_page_t p, pp;
- vm_object_offset_t new_offset, backing_offset;
- vm_object_size_t size;
+ vm_object_t new_copy = VM_OBJECT_NULL;
+ vm_object_t old_copy;
+ vm_page_t p;
+ vm_object_size_t copy_size = src_offset + size;
+ pmap_flush_context pmap_flush_context_storage;
+ boolean_t delayed_pmap_flush = FALSE;
- vm_object_lock_assert_exclusive(object);
- vm_object_lock_assert_exclusive(backing_object);
- backing_offset = object->shadow_offset;
- size = object->size;
+ int collisions = 0;
+ /*
+ * The user-level memory manager wants to see all of the changes
+ * to this object, but it has promised not to make any changes on
+ * its own.
+ *
+ * Perform an asymmetric copy-on-write, as follows:
+ * Create a new object, called a "copy object" to hold
+ * pages modified by the new mapping (i.e., the copy,
+ * not the original mapping).
+ * Record the original object as the backing object for
+ * the copy object. If the original mapping does not
+ * change a page, it may be used read-only by the copy.
+ * Record the copy object in the original object.
+ * When the original mapping causes a page to be modified,
+ * it must be copied to a new page that is "pushed" to
+ * the copy object.
+ * Mark the new mapping (the copy object) copy-on-write.
+ * This makes the copy object itself read-only, allowing
+ * it to be reused if the original mapping makes no
+ * changes, and simplifying the synchronization required
+ * in the "push" operation described above.
+ *
+ * The copy-on-write is said to be assymetric because the original
+ * object is *not* marked copy-on-write. A copied page is pushed
+ * to the copy object, regardless which party attempted to modify
+ * the page.
+ *
+ * Repeated asymmetric copy operations may be done. If the
+ * original object has not been changed since the last copy, its
+ * copy object can be reused. Otherwise, a new copy object can be
+ * inserted between the original object and its previous copy
+ * object. Since any copy object is read-only, this cannot affect
+ * affect the contents of the previous copy object.
+ *
+ * Note that a copy object is higher in the object tree than the
+ * original object; therefore, use of the copy object recorded in
+ * the original object must be done carefully, to avoid deadlock.
+ */
+ copy_size = vm_object_round_page(copy_size);
+ Retry:
+
/*
- * Move all in-memory pages from backing_object
- * to the parent. Pages that have been paged out
- * will be overwritten by any of the parent's
- * pages that shadow them.
+ * Wait for paging in progress.
*/
-
- while (!queue_empty(&backing_object->memq)) {
-
- p = (vm_page_t) queue_first(&backing_object->memq);
-
- new_offset = (p->offset - backing_offset);
-
- assert(!p->busy || p->absent);
+ if (!src_object->true_share &&
+ (src_object->paging_in_progress != 0 ||
+ src_object->activity_in_progress != 0)) {
+ if (src_object_shared == TRUE) {
+ vm_object_unlock(src_object);
+ vm_object_lock(src_object);
+ src_object_shared = FALSE;
+ goto Retry;
+ }
+ vm_object_paging_wait(src_object, THREAD_UNINT);
+ }
+ /*
+ * See whether we can reuse the result of a previous
+ * copy operation.
+ */
+
+ old_copy = src_object->copy;
+ if (old_copy != VM_OBJECT_NULL) {
+ int lock_granted;
/*
- * If the parent has a page here, or if
- * this page falls outside the parent,
- * dispose of it.
- *
- * Otherwise, move it as planned.
+ * Try to get the locks (out of order)
*/
-
- if (p->offset < backing_offset || new_offset >= size) {
- VM_PAGE_FREE(p);
- } else {
- /*
- * ENCRYPTED SWAP:
- * The encryption key includes the "pager" and the
- * "paging_offset". These will not change during the
- * object collapse, so we can just move an encrypted
- * page from one object to the other in this case.
- * We can't decrypt the page here, since we can't drop
- * the object lock.
- */
- if (p->encrypted) {
- vm_object_collapse_encrypted++;
- }
- pp = vm_page_lookup(object, new_offset);
- if (pp == VM_PAGE_NULL) {
+ if (src_object_shared == TRUE)
+ lock_granted = vm_object_lock_try_shared(old_copy);
+ else
+ lock_granted = vm_object_lock_try(old_copy);
- /*
- * Parent now has no page.
- * Move the backing object's page up.
- */
+ if (!lock_granted) {
+ vm_object_unlock(src_object);
- vm_page_rename(p, object, new_offset, TRUE);
-#if MACH_PAGEMAP
- } else if (pp->absent) {
+ if (collisions++ == 0)
+ copy_delayed_lock_contention++;
+ mutex_pause(collisions);
- /*
- * Parent has an absent page...
- * it's not being paged in, so
- * it must really be missing from
- * the parent.
- *
- * Throw out the absent page...
- * any faults looking for that
- * page will restart with the new
- * one.
- */
+ /* Heisenberg Rules */
+ copy_delayed_lock_collisions++;
- VM_PAGE_FREE(pp);
- vm_page_rename(p, object, new_offset, TRUE);
-#endif /* MACH_PAGEMAP */
- } else {
- assert(! pp->absent);
+ if (collisions > copy_delayed_max_collisions)
+ copy_delayed_max_collisions = collisions;
- /*
- * Parent object has a real page.
- * Throw away the backing object's
- * page.
- */
- VM_PAGE_FREE(p);
- }
- }
- }
-
-#if !MACH_PAGEMAP
- assert((!object->pager_created && (object->pager == MEMORY_OBJECT_NULL))
- || (!backing_object->pager_created
- && (backing_object->pager == MEMORY_OBJECT_NULL)));
-#else
- assert(!object->pager_created && object->pager == MEMORY_OBJECT_NULL);
-#endif /* !MACH_PAGEMAP */
+ if (src_object_shared == TRUE)
+ vm_object_lock_shared(src_object);
+ else
+ vm_object_lock(src_object);
- if (backing_object->pager != MEMORY_OBJECT_NULL) {
- vm_object_hash_entry_t entry;
+ goto Retry;
+ }
/*
- * Move the pager from backing_object to object.
- *
- * XXX We're only using part of the paging space
- * for keeps now... we ought to discard the
- * unused portion.
+ * Determine whether the old copy object has
+ * been modified.
*/
- assert(!object->paging_in_progress);
- assert(!object->activity_in_progress);
- object->pager = backing_object->pager;
+ if (old_copy->resident_page_count == 0 &&
+ !old_copy->pager_created) {
+ /*
+ * It has not been modified.
+ *
+ * Return another reference to
+ * the existing copy-object if
+ * we can safely grow it (if
+ * needed).
+ */
- if (backing_object->hashed) {
- lck_mtx_t *lck;
+ if (old_copy->vo_size < copy_size) {
+ if (src_object_shared == TRUE) {
+ vm_object_unlock(old_copy);
+ vm_object_unlock(src_object);
+
+ vm_object_lock(src_object);
+ src_object_shared = FALSE;
+ goto Retry;
+ }
+ /*
+ * We can't perform a delayed copy if any of the
+ * pages in the extended range are wired (because
+ * we can't safely take write permission away from
+ * wired pages). If the pages aren't wired, then
+ * go ahead and protect them.
+ */
+ copy_delayed_protect_iterate++;
- lck = vm_object_hash_lock_spin(backing_object->pager);
- entry = vm_object_hash_lookup(object->pager, FALSE);
- assert(entry != VM_OBJECT_HASH_ENTRY_NULL);
- entry->object = object;
- vm_object_hash_unlock(lck);
+ pmap_flush_context_init(&pmap_flush_context_storage);
+ delayed_pmap_flush = FALSE;
- object->hashed = TRUE;
+ vm_page_queue_iterate(&src_object->memq, p, vm_page_t, listq) {
+ if (!p->fictitious &&
+ p->offset >= old_copy->vo_size &&
+ p->offset < copy_size) {
+ if (VM_PAGE_WIRED(p)) {
+ vm_object_unlock(old_copy);
+ vm_object_unlock(src_object);
+
+ if (new_copy != VM_OBJECT_NULL) {
+ vm_object_unlock(new_copy);
+ vm_object_deallocate(new_copy);
+ }
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
+
+ return VM_OBJECT_NULL;
+ } else {
+ pmap_page_protect_options(VM_PAGE_GET_PHYS_PAGE(p), (VM_PROT_ALL & ~VM_PROT_WRITE),
+ PMAP_OPTIONS_NOFLUSH, (void *)&pmap_flush_context_storage);
+ delayed_pmap_flush = TRUE;
+ }
+ }
+ }
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
+
+ old_copy->vo_size = copy_size;
+ }
+ if (src_object_shared == TRUE)
+ vm_object_reference_shared(old_copy);
+ else
+ vm_object_reference_locked(old_copy);
+ vm_object_unlock(old_copy);
+ vm_object_unlock(src_object);
+
+ if (new_copy != VM_OBJECT_NULL) {
+ vm_object_unlock(new_copy);
+ vm_object_deallocate(new_copy);
+ }
+ return(old_copy);
}
- object->pager_created = backing_object->pager_created;
- object->pager_control = backing_object->pager_control;
- object->pager_ready = backing_object->pager_ready;
- object->pager_initialized = backing_object->pager_initialized;
- object->paging_offset =
- backing_object->paging_offset + backing_offset;
- if (object->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
- memory_object_control_collapse(object->pager_control,
- object);
+
+
+
+ /*
+ * Adjust the size argument so that the newly-created
+ * copy object will be large enough to back either the
+ * old copy object or the new mapping.
+ */
+ if (old_copy->vo_size > copy_size)
+ copy_size = old_copy->vo_size;
+
+ if (new_copy == VM_OBJECT_NULL) {
+ vm_object_unlock(old_copy);
+ vm_object_unlock(src_object);
+ new_copy = vm_object_allocate(copy_size);
+ vm_object_lock(src_object);
+ vm_object_lock(new_copy);
+
+ src_object_shared = FALSE;
+ goto Retry;
}
- }
+ new_copy->vo_size = copy_size;
-#if MACH_PAGEMAP
- /*
- * If the shadow offset is 0, the use the existence map from
- * the backing object if there is one. If the shadow offset is
- * not zero, toss it.
- *
- * XXX - If the shadow offset is not 0 then a bit copy is needed
- * if the map is to be salvaged. For now, we just just toss the
- * old map, giving the collapsed object no map. This means that
- * the pager is invoked for zero fill pages. If analysis shows
- * that this happens frequently and is a performance hit, then
- * this code should be fixed to salvage the map.
- */
- assert(object->existence_map == VM_EXTERNAL_NULL);
- if (backing_offset || (size != backing_object->size)) {
- vm_external_discarded++;
- vm_external_destroy(backing_object->existence_map,
- backing_object->size);
- }
- else {
- vm_external_collapsed++;
- object->existence_map = backing_object->existence_map;
- }
- backing_object->existence_map = VM_EXTERNAL_NULL;
-#endif /* MACH_PAGEMAP */
+ /*
+ * The copy-object is always made large enough to
+ * completely shadow the original object, since
+ * it may have several users who want to shadow
+ * the original object at different points.
+ */
- /*
- * Object now shadows whatever backing_object did.
- * Note that the reference to backing_object->shadow
- * moves from within backing_object to within object.
- */
-
- assert(!object->phys_contiguous);
- assert(!backing_object->phys_contiguous);
- object->shadow = backing_object->shadow;
- if (object->shadow) {
- object->shadow_offset += backing_object->shadow_offset;
- } else {
- /* no shadow, therefore no shadow offset... */
- object->shadow_offset = 0;
+ assert((old_copy->shadow == src_object) &&
+ (old_copy->vo_shadow_offset == (vm_object_offset_t) 0));
+
+ } else if (new_copy == VM_OBJECT_NULL) {
+ vm_object_unlock(src_object);
+ new_copy = vm_object_allocate(copy_size);
+ vm_object_lock(src_object);
+ vm_object_lock(new_copy);
+
+ src_object_shared = FALSE;
+ goto Retry;
}
- assert((object->shadow == VM_OBJECT_NULL) ||
- (object->shadow->copy != backing_object));
/*
- * Discard backing_object.
+ * We now have the src object locked, and the new copy object
+ * allocated and locked (and potentially the old copy locked).
+ * Before we go any further, make sure we can still perform
+ * a delayed copy, as the situation may have changed.
*
- * Since the backing object has no pages, no
- * pager left, and no object references within it,
- * all that is necessary is to dispose of it.
+ * Specifically, we can't perform a delayed copy if any of the
+ * pages in the range are wired (because we can't safely take
+ * write permission away from wired pages). If the pages aren't
+ * wired, then go ahead and protect them.
*/
-
- assert((backing_object->ref_count == 1) &&
- (backing_object->resident_page_count == 0) &&
- (backing_object->paging_in_progress == 0) &&
- (backing_object->activity_in_progress == 0));
+ copy_delayed_protect_iterate++;
- backing_object->alive = FALSE;
- vm_object_unlock(backing_object);
+ pmap_flush_context_init(&pmap_flush_context_storage);
+ delayed_pmap_flush = FALSE;
- XPR(XPR_VM_OBJECT, "vm_object_collapse, collapsed 0x%X\n",
- backing_object, 0,0,0,0);
+ vm_page_queue_iterate(&src_object->memq, p, vm_page_t, listq) {
+ if (!p->fictitious && p->offset < copy_size) {
+ if (VM_PAGE_WIRED(p)) {
+ if (old_copy)
+ vm_object_unlock(old_copy);
+ vm_object_unlock(src_object);
+ vm_object_unlock(new_copy);
+ vm_object_deallocate(new_copy);
- vm_object_lock_destroy(backing_object);
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
- zfree(vm_object_zone, backing_object);
-
- object_collapses++;
-}
+ return VM_OBJECT_NULL;
+ } else {
+ pmap_page_protect_options(VM_PAGE_GET_PHYS_PAGE(p), (VM_PROT_ALL & ~VM_PROT_WRITE),
+ PMAP_OPTIONS_NOFLUSH, (void *)&pmap_flush_context_storage);
+ delayed_pmap_flush = TRUE;
+ }
+ }
+ }
+ if (delayed_pmap_flush == TRUE)
+ pmap_flush(&pmap_flush_context_storage);
-static void
-vm_object_do_bypass(
- vm_object_t object,
- vm_object_t backing_object)
-{
- /*
- * Make the parent shadow the next object
- * in the chain.
- */
-
- vm_object_lock_assert_exclusive(object);
- vm_object_lock_assert_exclusive(backing_object);
+ if (old_copy != VM_OBJECT_NULL) {
+ /*
+ * Make the old copy-object shadow the new one.
+ * It will receive no more pages from the original
+ * object.
+ */
-#if TASK_SWAPPER
- /*
- * Do object reference in-line to
- * conditionally increment shadow's
- * residence count. If object is not
- * resident, leave residence count
- * on shadow alone.
- */
- if (backing_object->shadow != VM_OBJECT_NULL) {
- vm_object_lock(backing_object->shadow);
- vm_object_lock_assert_exclusive(backing_object->shadow);
- backing_object->shadow->ref_count++;
- if (object->res_count != 0)
- vm_object_res_reference(backing_object->shadow);
- vm_object_unlock(backing_object->shadow);
- }
-#else /* TASK_SWAPPER */
- vm_object_reference(backing_object->shadow);
-#endif /* TASK_SWAPPER */
+ /* remove ref. from old_copy */
+ vm_object_lock_assert_exclusive(src_object);
+ src_object->ref_count--;
+ assert(src_object->ref_count > 0);
+ vm_object_lock_assert_exclusive(old_copy);
+ old_copy->shadow = new_copy;
+ vm_object_lock_assert_exclusive(new_copy);
+ assert(new_copy->ref_count > 0);
+ new_copy->ref_count++; /* for old_copy->shadow ref. */
- assert(!object->phys_contiguous);
- assert(!backing_object->phys_contiguous);
- object->shadow = backing_object->shadow;
- if (object->shadow) {
- object->shadow_offset += backing_object->shadow_offset;
- } else {
- /* no shadow, therefore no shadow offset... */
- object->shadow_offset = 0;
+#if TASK_SWAPPER
+ if (old_copy->res_count) {
+ VM_OBJ_RES_INCR(new_copy);
+ VM_OBJ_RES_DECR(src_object);
+ }
+#endif
+
+ vm_object_unlock(old_copy); /* done with old_copy */
}
-
+
/*
- * Backing object might have had a copy pointer
- * to us. If it did, clear it.
+ * Point the new copy at the existing object.
*/
- if (backing_object->copy == object) {
- backing_object->copy = VM_OBJECT_NULL;
- }
-
- /*
- * Drop the reference count on backing_object.
-#if TASK_SWAPPER
- * Since its ref_count was at least 2, it
- * will not vanish; so we don't need to call
- * vm_object_deallocate.
- * [with a caveat for "named" objects]
- *
- * The res_count on the backing object is
- * conditionally decremented. It's possible
- * (via vm_pageout_scan) to get here with
- * a "swapped" object, which has a 0 res_count,
- * in which case, the backing object res_count
- * is already down by one.
-#else
- * Don't call vm_object_deallocate unless
- * ref_count drops to zero.
- *
- * The ref_count can drop to zero here if the
- * backing object could be bypassed but not
- * collapsed, such as when the backing object
- * is temporary and cachable.
-#endif
- */
- if (backing_object->ref_count > 2 ||
- (!backing_object->named && backing_object->ref_count > 1)) {
- vm_object_lock_assert_exclusive(backing_object);
- backing_object->ref_count--;
-#if TASK_SWAPPER
- if (object->res_count != 0)
- vm_object_res_deallocate(backing_object);
- assert(backing_object->ref_count > 0);
-#endif /* TASK_SWAPPER */
- vm_object_unlock(backing_object);
- } else {
-
- /*
- * Drop locks so that we can deallocate
- * the backing object.
- */
+ vm_object_lock_assert_exclusive(new_copy);
+ new_copy->shadow = src_object;
+ new_copy->vo_shadow_offset = 0;
+ new_copy->shadowed = TRUE; /* caller must set needs_copy */
-#if TASK_SWAPPER
- if (object->res_count == 0) {
- /* XXX get a reference for the deallocate below */
- vm_object_res_reference(backing_object);
- }
-#endif /* TASK_SWAPPER */
- vm_object_unlock(object);
- vm_object_unlock(backing_object);
- vm_object_deallocate(backing_object);
+ vm_object_lock_assert_exclusive(src_object);
+ vm_object_reference_locked(src_object);
+ src_object->copy = new_copy;
+ vm_object_unlock(src_object);
+ vm_object_unlock(new_copy);
- /*
- * Relock object. We don't have to reverify
- * its state since vm_object_collapse will
- * do that for us as it starts at the
- * top of its loop.
- */
+ XPR(XPR_VM_OBJECT,
+ "vm_object_copy_delayed: used copy object %X for source %X\n",
+ new_copy, src_object, 0, 0, 0);
- vm_object_lock(object);
- }
-
- object_bypasses++;
+ return new_copy;
}
-
/*
- * vm_object_collapse:
- *
- * Perform an object collapse or an object bypass if appropriate.
- * The real work of collapsing and bypassing is performed in
- * the routines vm_object_do_collapse and vm_object_do_bypass.
- *
- * Requires that the object be locked and the page queues be unlocked.
+ * Routine: vm_object_copy_strategically
*
+ * Purpose:
+ * Perform a copy according to the source object's
+ * declared strategy. This operation may block,
+ * and may be interrupted.
*/
-static unsigned long vm_object_collapse_calls = 0;
-static unsigned long vm_object_collapse_objects = 0;
-static unsigned long vm_object_collapse_do_collapse = 0;
-static unsigned long vm_object_collapse_do_bypass = 0;
-static unsigned long vm_object_collapse_delays = 0;
-__private_extern__ void
-vm_object_collapse(
- register vm_object_t object,
- register vm_object_offset_t hint_offset,
- boolean_t can_bypass)
+__private_extern__ kern_return_t
+vm_object_copy_strategically(
+ vm_object_t src_object,
+ vm_object_offset_t src_offset,
+ vm_object_size_t size,
+ vm_object_t *dst_object, /* OUT */
+ vm_object_offset_t *dst_offset, /* OUT */
+ boolean_t *dst_needs_copy) /* OUT */
{
- register vm_object_t backing_object;
- register unsigned int rcount;
- register unsigned int size;
- vm_object_t original_object;
- int object_lock_type;
- int backing_object_lock_type;
-
- vm_object_collapse_calls++;
-
- if (! vm_object_collapse_allowed &&
- ! (can_bypass && vm_object_bypass_allowed)) {
- return;
- }
+ boolean_t result;
+ boolean_t interruptible = THREAD_ABORTSAFE; /* XXX */
+ boolean_t object_lock_shared = FALSE;
+ memory_object_copy_strategy_t copy_strategy;
- XPR(XPR_VM_OBJECT, "vm_object_collapse, obj 0x%X\n",
- object, 0,0,0,0);
+ assert(src_object != VM_OBJECT_NULL);
- if (object == VM_OBJECT_NULL)
- return;
+ copy_strategy = src_object->copy_strategy;
- original_object = object;
+ if (copy_strategy == MEMORY_OBJECT_COPY_DELAY) {
+ vm_object_lock_shared(src_object);
+ object_lock_shared = TRUE;
+ } else
+ vm_object_lock(src_object);
/*
- * The top object was locked "exclusive" by the caller.
- * In the first pass, to determine if we can collapse the shadow chain,
- * take a "shared" lock on the shadow objects. If we can collapse,
- * we'll have to go down the chain again with exclusive locks.
+ * The copy strategy is only valid if the memory manager
+ * is "ready". Internal objects are always ready.
*/
- object_lock_type = OBJECT_LOCK_EXCLUSIVE;
- backing_object_lock_type = OBJECT_LOCK_SHARED;
-
-retry:
- object = original_object;
- vm_object_lock_assert_exclusive(object);
- while (TRUE) {
- vm_object_collapse_objects++;
- /*
- * Verify that the conditions are right for either
- * collapse or bypass:
- */
+ while (!src_object->internal && !src_object->pager_ready) {
+ wait_result_t wait_result;
- /*
- * There is a backing object, and
- */
-
- backing_object = object->shadow;
- if (backing_object == VM_OBJECT_NULL) {
- if (object != original_object) {
- vm_object_unlock(object);
- }
- return;
+ if (object_lock_shared == TRUE) {
+ vm_object_unlock(src_object);
+ vm_object_lock(src_object);
+ object_lock_shared = FALSE;
+ continue;
}
- if (backing_object_lock_type == OBJECT_LOCK_SHARED) {
- vm_object_lock_shared(backing_object);
- } else {
- vm_object_lock(backing_object);
+ wait_result = vm_object_sleep( src_object,
+ VM_OBJECT_EVENT_PAGER_READY,
+ interruptible);
+ if (wait_result != THREAD_AWAKENED) {
+ vm_object_unlock(src_object);
+ *dst_object = VM_OBJECT_NULL;
+ *dst_offset = 0;
+ *dst_needs_copy = FALSE;
+ return(MACH_SEND_INTERRUPTED);
}
+ }
- /*
- * No pages in the object are currently
- * being paged out, and
- */
- if (object->paging_in_progress != 0 ||
- object->activity_in_progress != 0) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
+ /*
+ * Use the appropriate copy strategy.
+ */
+
+ switch (copy_strategy) {
+ case MEMORY_OBJECT_COPY_DELAY:
+ *dst_object = vm_object_copy_delayed(src_object,
+ src_offset, size, object_lock_shared);
+ if (*dst_object != VM_OBJECT_NULL) {
+ *dst_offset = src_offset;
+ *dst_needs_copy = TRUE;
+ result = KERN_SUCCESS;
+ break;
}
+ vm_object_lock(src_object);
+ /* fall thru when delayed copy not allowed */
- /*
- * ...
- * The backing object is not read_only,
- * and no pages in the backing object are
- * currently being paged out.
- * The backing object is internal.
- *
- */
-
- if (!backing_object->internal ||
- backing_object->paging_in_progress != 0 ||
- backing_object->activity_in_progress != 0) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
+ case MEMORY_OBJECT_COPY_NONE:
+ result = vm_object_copy_slowly(src_object, src_offset, size,
+ interruptible, dst_object);
+ if (result == KERN_SUCCESS) {
+ *dst_offset = 0;
+ *dst_needs_copy = FALSE;
}
-
- /*
- * The backing object can't be a copy-object:
- * the shadow_offset for the copy-object must stay
- * as 0. Furthermore (for the 'we have all the
- * pages' case), if we bypass backing_object and
- * just shadow the next object in the chain, old
- * pages from that object would then have to be copied
- * BOTH into the (former) backing_object and into the
- * parent object.
- */
- if (backing_object->shadow != VM_OBJECT_NULL &&
- backing_object->shadow->copy == backing_object) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
+ break;
+
+ case MEMORY_OBJECT_COPY_CALL:
+ result = vm_object_copy_call(src_object, src_offset, size,
+ dst_object);
+ if (result == KERN_SUCCESS) {
+ *dst_offset = src_offset;
+ *dst_needs_copy = TRUE;
}
+ break;
- /*
- * We can now try to either collapse the backing
- * object (if the parent is the only reference to
- * it) or (perhaps) remove the parent's reference
- * to it.
- *
- * If there is exactly one reference to the backing
- * object, we may be able to collapse it into the
- * parent.
- *
- * If MACH_PAGEMAP is defined:
- * The parent must not have a pager created for it,
- * since collapsing a backing_object dumps new pages
- * into the parent that its pager doesn't know about
- * (and the collapse code can't merge the existence
- * maps).
- * Otherwise:
- * As long as one of the objects is still not known
- * to the pager, we can collapse them.
- */
- if (backing_object->ref_count == 1 &&
- (!object->pager_created
-#if !MACH_PAGEMAP
- || !backing_object->pager_created
-#endif /*!MACH_PAGEMAP */
- ) && vm_object_collapse_allowed) {
-
- /*
- * We need the exclusive lock on the VM objects.
- */
- if (backing_object_lock_type != OBJECT_LOCK_EXCLUSIVE) {
- /*
- * We have an object and its shadow locked
- * "shared". We can't just upgrade the locks
- * to "exclusive", as some other thread might
- * also have these objects locked "shared" and
- * attempt to upgrade one or the other to
- * "exclusive". The upgrades would block
- * forever waiting for the other "shared" locks
- * to get released.
- * So we have to release the locks and go
- * down the shadow chain again (since it could
- * have changed) with "exclusive" locking.
- */
- vm_object_unlock(backing_object);
- if (object != original_object)
- vm_object_unlock(object);
- object_lock_type = OBJECT_LOCK_EXCLUSIVE;
- backing_object_lock_type = OBJECT_LOCK_EXCLUSIVE;
- goto retry;
- }
-
- XPR(XPR_VM_OBJECT,
- "vm_object_collapse: %x to %x, pager %x, pager_control %x\n",
- backing_object, object,
- backing_object->pager,
- backing_object->pager_control, 0);
-
- /*
- * Collapse the object with its backing
- * object, and try again with the object's
- * new backing object.
- */
-
- vm_object_do_collapse(object, backing_object);
- vm_object_collapse_do_collapse++;
- continue;
- }
-
- /*
- * Collapsing the backing object was not possible
- * or permitted, so let's try bypassing it.
- */
+ case MEMORY_OBJECT_COPY_SYMMETRIC:
+ XPR(XPR_VM_OBJECT, "v_o_c_strategically obj 0x%x off 0x%x size 0x%x\n", src_object, src_offset, size, 0, 0);
+ vm_object_unlock(src_object);
+ result = KERN_MEMORY_RESTART_COPY;
+ break;
- if (! (can_bypass && vm_object_bypass_allowed)) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
+ default:
+ panic("copy_strategically: bad strategy");
+ result = KERN_INVALID_ARGUMENT;
+ }
+ return(result);
+}
+/*
+ * vm_object_shadow:
+ *
+ * Create a new object which is backed by the
+ * specified existing object range. The source
+ * object reference is deallocated.
+ *
+ * The new object and offset into that object
+ * are returned in the source parameters.
+ */
+boolean_t vm_object_shadow_check = TRUE;
- /*
- * If the object doesn't have all its pages present,
- * we have to make sure no pages in the backing object
- * "show through" before bypassing it.
- */
- size = atop(object->size);
- rcount = object->resident_page_count;
- if (rcount != size) {
- vm_object_offset_t offset;
- vm_object_offset_t backing_offset;
- unsigned int backing_rcount;
- unsigned int lookups = 0;
+__private_extern__ boolean_t
+vm_object_shadow(
+ vm_object_t *object, /* IN/OUT */
+ vm_object_offset_t *offset, /* IN/OUT */
+ vm_object_size_t length)
+{
+ vm_object_t source;
+ vm_object_t result;
- /*
- * If the backing object has a pager but no pagemap,
- * then we cannot bypass it, because we don't know
- * what pages it has.
- */
- if (backing_object->pager_created
-#if MACH_PAGEMAP
- && (backing_object->existence_map == VM_EXTERNAL_NULL)
-#endif /* MACH_PAGEMAP */
- ) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
+ source = *object;
+ assert(source != VM_OBJECT_NULL);
+ if (source == VM_OBJECT_NULL)
+ return FALSE;
- /*
- * If the object has a pager but no pagemap,
- * then we cannot bypass it, because we don't know
- * what pages it has.
- */
- if (object->pager_created
-#if MACH_PAGEMAP
- && (object->existence_map == VM_EXTERNAL_NULL)
-#endif /* MACH_PAGEMAP */
- ) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
+#if 0
+ /*
+ * XXX FBDP
+ * This assertion is valid but it gets triggered by Rosetta for example
+ * due to a combination of vm_remap() that changes a VM object's
+ * copy_strategy from SYMMETRIC to DELAY and vm_protect(VM_PROT_COPY)
+ * that then sets "needs_copy" on its map entry. This creates a
+ * mapping situation that VM should never see and doesn't know how to
+ * handle.
+ * It's not clear if this can create any real problem but we should
+ * look into fixing this, probably by having vm_protect(VM_PROT_COPY)
+ * do more than just set "needs_copy" to handle the copy-on-write...
+ * In the meantime, let's disable the assertion.
+ */
+ assert(source->copy_strategy == MEMORY_OBJECT_COPY_SYMMETRIC);
+#endif
- /*
- * If all of the pages in the backing object are
- * shadowed by the parent object, the parent
- * object no longer has to shadow the backing
- * object; it can shadow the next one in the
- * chain.
- *
- * If the backing object has existence info,
- * we must check examine its existence info
- * as well.
- *
- */
+ /*
+ * Determine if we really need a shadow.
+ *
+ * If the source object is larger than what we are trying
+ * to create, then force the shadow creation even if the
+ * ref count is 1. This will allow us to [potentially]
+ * collapse the underlying object away in the future
+ * (freeing up the extra data it might contain and that
+ * we don't need).
+ */
- backing_offset = object->shadow_offset;
- backing_rcount = backing_object->resident_page_count;
+ assert(source->copy_strategy != MEMORY_OBJECT_COPY_NONE); /* Purgeable objects shouldn't have shadow objects. */
-#if MACH_PAGEMAP
-#define EXISTS_IN_OBJECT(obj, off, rc) \
- (vm_external_state_get((obj)->existence_map, \
- (vm_offset_t)(off)) == VM_EXTERNAL_STATE_EXISTS || \
- ((rc) && ++lookups && vm_page_lookup((obj), (off)) != VM_PAGE_NULL && (rc)--))
-#else
-#define EXISTS_IN_OBJECT(obj, off, rc) \
- (((rc) && ++lookups && vm_page_lookup((obj), (off)) != VM_PAGE_NULL && (rc)--))
-#endif /* MACH_PAGEMAP */
+ if (vm_object_shadow_check &&
+ source->vo_size == length &&
+ source->ref_count == 1 &&
+ (source->shadow == VM_OBJECT_NULL ||
+ source->shadow->copy == VM_OBJECT_NULL) )
+ {
+ /* lock the object and check again */
+ vm_object_lock(source);
+ if (source->vo_size == length &&
+ source->ref_count == 1 &&
+ (source->shadow == VM_OBJECT_NULL ||
+ source->shadow->copy == VM_OBJECT_NULL))
+ {
+ source->shadowed = FALSE;
+ vm_object_unlock(source);
+ return FALSE;
+ }
+ /* things changed while we were locking "source"... */
+ vm_object_unlock(source);
+ }
- /*
- * Check the hint location first
- * (since it is often the quickest way out of here).
- */
- if (object->cow_hint != ~(vm_offset_t)0)
- hint_offset = (vm_object_offset_t)object->cow_hint;
- else
- hint_offset = (hint_offset > 8 * PAGE_SIZE_64) ?
- (hint_offset - 8 * PAGE_SIZE_64) : 0;
+ /*
+ * Allocate a new object with the given length
+ */
- if (EXISTS_IN_OBJECT(backing_object, hint_offset +
- backing_offset, backing_rcount) &&
- !EXISTS_IN_OBJECT(object, hint_offset, rcount)) {
- /* dependency right at the hint */
- object->cow_hint = (vm_offset_t) hint_offset; /* atomic */
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
+ if ((result = vm_object_allocate(length)) == VM_OBJECT_NULL)
+ panic("vm_object_shadow: no object for shadowing");
- /*
- * If the object's window onto the backing_object
- * is large compared to the number of resident
- * pages in the backing object, it makes sense to
- * walk the backing_object's resident pages first.
- *
- * NOTE: Pages may be in both the existence map and
- * resident. So, we can't permanently decrement
- * the rcount here because the second loop may
- * find the same pages in the backing object'
- * existence map that we found here and we would
- * double-decrement the rcount. We also may or
- * may not have found the
- */
- if (backing_rcount &&
-#if MACH_PAGEMAP
- size > ((backing_object->existence_map) ?
- backing_rcount : (backing_rcount >> 1))
-#else
- size > (backing_rcount >> 1)
-#endif /* MACH_PAGEMAP */
- ) {
- unsigned int rc = rcount;
- vm_page_t p;
+ /*
+ * The new object shadows the source object, adding
+ * a reference to it. Our caller changes his reference
+ * to point to the new object, removing a reference to
+ * the source object. Net result: no change of reference
+ * count.
+ */
+ result->shadow = source;
+
+ /*
+ * Store the offset into the source object,
+ * and fix up the offset into the new object.
+ */
- backing_rcount = backing_object->resident_page_count;
- p = (vm_page_t)queue_first(&backing_object->memq);
- do {
- /* Until we get more than one lookup lock */
- if (lookups > 256) {
- vm_object_collapse_delays++;
- lookups = 0;
- mutex_pause(0);
- }
+ result->vo_shadow_offset = *offset;
- offset = (p->offset - backing_offset);
- if (offset < object->size &&
- offset != hint_offset &&
- !EXISTS_IN_OBJECT(object, offset, rc)) {
- /* found a dependency */
- object->cow_hint = (vm_offset_t) offset; /* atomic */
-
- break;
- }
- p = (vm_page_t) queue_next(&p->listq);
+ /*
+ * Return the new things
+ */
- } while (--backing_rcount);
- if (backing_rcount != 0 ) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
- }
-
- /*
- * Walk through the offsets looking for pages in the
- * backing object that show through to the object.
- */
- if (backing_rcount
-#if MACH_PAGEMAP
- || backing_object->existence_map
-#endif /* MACH_PAGEMAP */
- ) {
- offset = hint_offset;
-
- while((offset =
- (offset + PAGE_SIZE_64 < object->size) ?
- (offset + PAGE_SIZE_64) : 0) != hint_offset) {
-
- /* Until we get more than one lookup lock */
- if (lookups > 256) {
- vm_object_collapse_delays++;
- lookups = 0;
- mutex_pause(0);
- }
-
- if (EXISTS_IN_OBJECT(backing_object, offset +
- backing_offset, backing_rcount) &&
- !EXISTS_IN_OBJECT(object, offset, rcount)) {
- /* found a dependency */
- object->cow_hint = (vm_offset_t) offset; /* atomic */
- break;
- }
- }
- if (offset != hint_offset) {
- /* try and collapse the rest of the shadow chain */
- if (object != original_object) {
- vm_object_unlock(object);
- }
- object = backing_object;
- object_lock_type = backing_object_lock_type;
- continue;
- }
- }
- }
-
- /*
- * We need "exclusive" locks on the 2 VM objects.
- */
- if (backing_object_lock_type != OBJECT_LOCK_EXCLUSIVE) {
- vm_object_unlock(backing_object);
- if (object != original_object)
- vm_object_unlock(object);
- object_lock_type = OBJECT_LOCK_EXCLUSIVE;
- backing_object_lock_type = OBJECT_LOCK_EXCLUSIVE;
- goto retry;
- }
-
- /* reset the offset hint for any objects deeper in the chain */
- object->cow_hint = (vm_offset_t)0;
-
- /*
- * All interesting pages in the backing object
- * already live in the parent or its pager.
- * Thus we can bypass the backing object.
- */
-
- vm_object_do_bypass(object, backing_object);
- vm_object_collapse_do_bypass++;
-
- /*
- * Try again with this object's new backing object.
- */
-
- continue;
- }
-
- if (object != original_object) {
- vm_object_unlock(object);
- }
-}
+ *offset = 0;
+ *object = result;
+ return TRUE;
+}
/*
- * Routine: vm_object_page_remove: [internal]
- * Purpose:
- * Removes all physical pages in the specified
- * object range from the object's list of pages.
+ * The relationship between vm_object structures and
+ * the memory_object requires careful synchronization.
*
- * In/out conditions:
- * The object must be locked.
- * The object must not have paging_in_progress, usually
- * guaranteed by not having a pager.
- */
-unsigned int vm_object_page_remove_lookup = 0;
-unsigned int vm_object_page_remove_iterate = 0;
-
-__private_extern__ void
-vm_object_page_remove(
- register vm_object_t object,
- register vm_object_offset_t start,
- register vm_object_offset_t end)
-{
- register vm_page_t p, next;
-
- /*
- * One and two page removals are most popular.
- * The factor of 16 here is somewhat arbitrary.
- * It balances vm_object_lookup vs iteration.
- */
-
- if (atop_64(end - start) < (unsigned)object->resident_page_count/16) {
- vm_object_page_remove_lookup++;
-
- for (; start < end; start += PAGE_SIZE_64) {
- p = vm_page_lookup(object, start);
- if (p != VM_PAGE_NULL) {
- assert(!p->cleaning && !p->pageout);
- if (!p->fictitious && p->pmapped)
- pmap_disconnect(p->phys_page);
- VM_PAGE_FREE(p);
- }
- }
- } else {
- vm_object_page_remove_iterate++;
-
- p = (vm_page_t) queue_first(&object->memq);
- while (!queue_end(&object->memq, (queue_entry_t) p)) {
- next = (vm_page_t) queue_next(&p->listq);
- if ((start <= p->offset) && (p->offset < end)) {
- assert(!p->cleaning && !p->pageout);
- if (!p->fictitious && p->pmapped)
- pmap_disconnect(p->phys_page);
- VM_PAGE_FREE(p);
- }
- p = next;
- }
- }
-}
-
-
-/*
- * Routine: vm_object_coalesce
- * Function: Coalesces two objects backing up adjoining
- * regions of memory into a single object.
+ * All associations are created by memory_object_create_named
+ * for external pagers and vm_object_compressor_pager_create for internal
+ * objects as follows:
*
- * returns TRUE if objects were combined.
+ * pager: the memory_object itself, supplied by
+ * the user requesting a mapping (or the kernel,
+ * when initializing internal objects); the
+ * kernel simulates holding send rights by keeping
+ * a port reference;
*
- * NOTE: Only works at the moment if the second object is NULL -
- * if it's not, which object do we lock first?
+ * pager_request:
+ * the memory object control port,
+ * created by the kernel; the kernel holds
+ * receive (and ownership) rights to this
+ * port, but no other references.
*
- * Parameters:
- * prev_object First object to coalesce
- * prev_offset Offset into prev_object
- * next_object Second object into coalesce
- * next_offset Offset into next_object
+ * When initialization is complete, the "initialized" field
+ * is asserted. Other mappings using a particular memory object,
+ * and any references to the vm_object gained through the
+ * port association must wait for this initialization to occur.
*
- * prev_size Size of reference to prev_object
- * next_size Size of reference to next_object
+ * In order to allow the memory manager to set attributes before
+ * requests (notably virtual copy operations, but also data or
+ * unlock requests) are made, a "ready" attribute is made available.
+ * Only the memory manager may affect the value of this attribute.
+ * Its value does not affect critical kernel functions, such as
+ * internal object initialization or destruction. [Furthermore,
+ * memory objects created by the kernel are assumed to be ready
+ * immediately; the default memory manager need not explicitly
+ * set the "ready" attribute.]
*
- * Conditions:
- * The object(s) must *not* be locked. The map must be locked
- * to preserve the reference to the object(s).
+ * [Both the "initialized" and "ready" attribute wait conditions
+ * use the "pager" field as the wait event.]
+ *
+ * The port associations can be broken down by any of the
+ * following routines:
+ * vm_object_terminate:
+ * No references to the vm_object remain, and
+ * the object cannot (or will not) be cached.
+ * This is the normal case, and is done even
+ * though one of the other cases has already been
+ * done.
+ * memory_object_destroy:
+ * The memory manager has requested that the
+ * kernel relinquish references to the memory
+ * object. [The memory manager may not want to
+ * destroy the memory object, but may wish to
+ * refuse or tear down existing memory mappings.]
+ *
+ * Each routine that breaks an association must break all of
+ * them at once. At some later time, that routine must clear
+ * the pager field and release the memory object references.
+ * [Furthermore, each routine must cope with the simultaneous
+ * or previous operations of the others.]
+ *
+ * In addition to the lock on the object, the vm_object_hash_lock
+ * governs the associations. References gained through the
+ * association require use of the hash lock.
+ *
+ * Because the pager field may be cleared spontaneously, it
+ * cannot be used to determine whether a memory object has
+ * ever been associated with a particular vm_object. [This
+ * knowledge is important to the shadow object mechanism.]
+ * For this reason, an additional "created" attribute is
+ * provided.
+ *
+ * During various paging operations, the pager reference found in the
+ * vm_object must be valid. To prevent this from being released,
+ * (other than being removed, i.e., made null), routines may use
+ * the vm_object_paging_begin/end routines [actually, macros].
+ * The implementation uses the "paging_in_progress" and "wanted" fields.
+ * [Operations that alter the validity of the pager values include the
+ * termination routines and vm_object_collapse.]
*/
-static int vm_object_coalesce_count = 0;
-
-__private_extern__ boolean_t
-vm_object_coalesce(
- register vm_object_t prev_object,
- vm_object_t next_object,
- vm_object_offset_t prev_offset,
- __unused vm_object_offset_t next_offset,
- vm_object_size_t prev_size,
- vm_object_size_t next_size)
-{
- vm_object_size_t newsize;
-
-#ifdef lint
- next_offset++;
-#endif /* lint */
- if (next_object != VM_OBJECT_NULL) {
- return(FALSE);
- }
- if (prev_object == VM_OBJECT_NULL) {
- return(TRUE);
- }
+/*
+ * Routine: vm_object_enter
+ * Purpose:
+ * Find a VM object corresponding to the given
+ * pager; if no such object exists, create one,
+ * and initialize the pager.
+ */
+vm_object_t
+vm_object_enter(
+ memory_object_t pager,
+ vm_object_size_t size,
+ boolean_t internal,
+ boolean_t init,
+ boolean_t named)
+{
+ vm_object_t object;
+ vm_object_t new_object;
+ boolean_t must_init;
+ vm_object_hash_entry_t entry, new_entry;
+ uint32_t try_failed_count = 0;
+ lck_mtx_t *lck;
- XPR(XPR_VM_OBJECT,
- "vm_object_coalesce: 0x%X prev_off 0x%X prev_size 0x%X next_size 0x%X\n",
- prev_object, prev_offset, prev_size, next_size, 0);
+ if (pager == MEMORY_OBJECT_NULL)
+ return(vm_object_allocate(size));
- vm_object_lock(prev_object);
+ new_object = VM_OBJECT_NULL;
+ new_entry = VM_OBJECT_HASH_ENTRY_NULL;
+ must_init = init;
/*
- * Try to collapse the object first
+ * Look for an object associated with this port.
*/
- vm_object_collapse(prev_object, prev_offset, TRUE);
+Retry:
+ lck = vm_object_hash_lock_spin(pager);
+ do {
+ entry = vm_object_hash_lookup(pager, FALSE);
- /*
- * Can't coalesce if pages not mapped to
- * prev_entry may be in use any way:
- * . more than one reference
- * . paged out
- * . shadows another object
- * . has a copy elsewhere
- * . is purgeable
- * . paging references (pages might be in page-list)
- */
+ if (entry == VM_OBJECT_HASH_ENTRY_NULL) {
+ if (new_object == VM_OBJECT_NULL) {
+ /*
+ * We must unlock to create a new object;
+ * if we do so, we must try the lookup again.
+ */
+ vm_object_hash_unlock(lck);
+ assert(new_entry == VM_OBJECT_HASH_ENTRY_NULL);
+ new_entry = vm_object_hash_entry_alloc(pager);
+ new_object = vm_object_allocate(size);
+ /*
+ * Set new_object->hashed now, while noone
+ * knows about this object yet and we
+ * don't need to lock it. Once it's in
+ * the hash table, we would have to lock
+ * the object to set its "hashed" bit and
+ * we can't lock the object while holding
+ * the hash lock as a spinlock...
+ */
+ new_object->hashed = TRUE;
+ lck = vm_object_hash_lock_spin(pager);
+ } else {
+ /*
+ * Lookup failed twice, and we have something
+ * to insert; set the object.
+ */
+ /*
+ * We can't lock the object here since we're
+ * holding the hash lock as a spin lock.
+ * We've already pre-set "new_object->hashed"
+ * when we created "new_object" above, so we
+ * won't need to modify the object in
+ * vm_object_hash_insert().
+ */
+ assert(new_object->hashed);
+ vm_object_hash_insert(new_entry, new_object);
+ entry = new_entry;
+ new_entry = VM_OBJECT_HASH_ENTRY_NULL;
+ new_object = VM_OBJECT_NULL;
+ must_init = TRUE;
+ }
+ } else if (entry->object == VM_OBJECT_NULL) {
+ /*
+ * If a previous object is being terminated,
+ * we must wait for the termination message
+ * to be queued (and lookup the entry again).
+ */
+ entry->waiting = TRUE;
+ entry = VM_OBJECT_HASH_ENTRY_NULL;
+ assert_wait((event_t) pager, THREAD_UNINT);
+ vm_object_hash_unlock(lck);
- if ((prev_object->ref_count > 1) ||
- prev_object->pager_created ||
- (prev_object->shadow != VM_OBJECT_NULL) ||
- (prev_object->copy != VM_OBJECT_NULL) ||
- (prev_object->true_share != FALSE) ||
- (prev_object->purgable != VM_PURGABLE_DENY) ||
- (prev_object->paging_in_progress != 0) ||
- (prev_object->activity_in_progress != 0)) {
- vm_object_unlock(prev_object);
- return(FALSE);
- }
+ thread_block(THREAD_CONTINUE_NULL);
+ lck = vm_object_hash_lock_spin(pager);
+ }
+ } while (entry == VM_OBJECT_HASH_ENTRY_NULL);
- vm_object_coalesce_count++;
+ object = entry->object;
+ assert(object != VM_OBJECT_NULL);
- /*
- * Remove any pages that may still be in the object from
- * a previous deallocation.
- */
- vm_object_page_remove(prev_object,
- prev_offset + prev_size,
- prev_offset + prev_size + next_size);
+ if (!must_init) {
+ if ( !vm_object_lock_try(object)) {
- /*
- * Extend the object if necessary.
- */
- newsize = prev_offset + prev_size + next_size;
- if (newsize > prev_object->size) {
-#if MACH_PAGEMAP
- /*
- * We cannot extend an object that has existence info,
- * since the existence info might then fail to cover
- * the entire object.
- *
- * This assertion must be true because the object
- * has no pager, and we only create existence info
- * for objects with pagers.
- */
- assert(prev_object->existence_map == VM_EXTERNAL_NULL);
-#endif /* MACH_PAGEMAP */
- prev_object->size = newsize;
- }
+ vm_object_hash_unlock(lck);
- vm_object_unlock(prev_object);
- return(TRUE);
-}
+ try_failed_count++;
+ mutex_pause(try_failed_count); /* wait a bit */
+ goto Retry;
+ }
+ assert(!internal || object->internal);
+#if VM_OBJECT_CACHE
+ if (object->ref_count == 0) {
+ if ( !vm_object_cache_lock_try()) {
-/*
- * Attach a set of physical pages to an object, so that they can
- * be mapped by mapping the object. Typically used to map IO memory.
- *
- * The mapping function and its private data are used to obtain the
- * physical addresses for each page to be mapped.
- */
-void
-vm_object_page_map(
- vm_object_t object,
- vm_object_offset_t offset,
- vm_object_size_t size,
- vm_object_offset_t (*map_fn)(void *map_fn_data,
- vm_object_offset_t offset),
- void *map_fn_data) /* private to map_fn */
-{
- int64_t num_pages;
- int i;
- vm_page_t m;
- vm_page_t old_page;
- vm_object_offset_t addr;
+ vm_object_hash_unlock(lck);
+ vm_object_unlock(object);
+
+ try_failed_count++;
+ mutex_pause(try_failed_count); /* wait a bit */
+ goto Retry;
+ }
+ XPR(XPR_VM_OBJECT_CACHE,
+ "vm_object_enter: removing %x from cache, head (%x, %x)\n",
+ object,
+ vm_object_cached_list.next,
+ vm_object_cached_list.prev, 0,0);
+ queue_remove(&vm_object_cached_list, object,
+ vm_object_t, cached_list);
+ vm_object_cached_count--;
+
+ vm_object_cache_unlock();
+ }
+#endif
+ if (named) {
+ assert(!object->named);
+ object->named = TRUE;
+ }
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count++;
+ vm_object_res_reference(object);
- num_pages = atop_64(size);
+ vm_object_hash_unlock(lck);
+ vm_object_unlock(object);
- for (i = 0; i < num_pages; i++, offset += PAGE_SIZE_64) {
+ VM_STAT_INCR(hits);
+ } else
+ vm_object_hash_unlock(lck);
- addr = (*map_fn)(map_fn_data, offset);
+ assert(object->ref_count > 0);
- while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL)
- vm_page_more_fictitious();
+ VM_STAT_INCR(lookups);
- vm_object_lock(object);
- if ((old_page = vm_page_lookup(object, offset))
- != VM_PAGE_NULL)
- {
- VM_PAGE_FREE(old_page);
- }
+ XPR(XPR_VM_OBJECT,
+ "vm_o_enter: pager 0x%x obj 0x%x must_init %d\n",
+ pager, object, must_init, 0, 0);
- assert((ppnum_t) addr == addr);
- vm_page_init(m, (ppnum_t) addr);
- /*
- * private normally requires lock_queues but since we
- * are initializing the page, its not necessary here
- */
- m->private = TRUE; /* don`t free page */
- m->wire_count = 1;
- vm_page_insert(m, object, offset);
+ /*
+ * If we raced to create a vm_object but lost, let's
+ * throw away ours.
+ */
- PAGE_WAKEUP_DONE(m);
- vm_object_unlock(object);
+ if (new_object != VM_OBJECT_NULL) {
+ /*
+ * Undo the pre-setting of "new_object->hashed" before
+ * deallocating "new_object", since we did not insert it
+ * into the hash table after all.
+ */
+ assert(new_object->hashed);
+ new_object->hashed = FALSE;
+ vm_object_deallocate(new_object);
}
-}
-#include <mach_kdb.h>
+ if (new_entry != VM_OBJECT_HASH_ENTRY_NULL)
+ vm_object_hash_entry_free(new_entry);
+
+ if (must_init) {
+ memory_object_control_t control;
+
+ /*
+ * Allocate request port.
+ */
-#if MACH_KDB
-#include <ddb/db_output.h>
-#include <vm/vm_print.h>
+ control = memory_object_control_allocate(object);
+ assert (control != MEMORY_OBJECT_CONTROL_NULL);
-#define printf kdbprintf
+ vm_object_lock(object);
+ assert(object != kernel_object);
-extern boolean_t vm_object_cached(
- vm_object_t object);
+ /*
+ * Copy the reference we were given.
+ */
-extern void print_bitstring(
- char byte);
+ memory_object_reference(pager);
+ object->pager_created = TRUE;
+ object->pager = pager;
+ object->internal = internal;
+ object->pager_trusted = internal;
+ if (!internal) {
+ /* copy strategy invalid until set by memory manager */
+ object->copy_strategy = MEMORY_OBJECT_COPY_INVALID;
+ }
+ object->pager_control = control;
+ object->pager_ready = FALSE;
-boolean_t vm_object_print_pages = FALSE;
+ vm_object_unlock(object);
-void
-print_bitstring(
- char byte)
-{
- printf("%c%c%c%c%c%c%c%c",
- ((byte & (1 << 0)) ? '1' : '0'),
- ((byte & (1 << 1)) ? '1' : '0'),
- ((byte & (1 << 2)) ? '1' : '0'),
- ((byte & (1 << 3)) ? '1' : '0'),
- ((byte & (1 << 4)) ? '1' : '0'),
- ((byte & (1 << 5)) ? '1' : '0'),
- ((byte & (1 << 6)) ? '1' : '0'),
- ((byte & (1 << 7)) ? '1' : '0'));
-}
+ /*
+ * Let the pager know we're using it.
+ */
-boolean_t
-vm_object_cached(
- __unused register vm_object_t object)
-{
-#if VM_OBJECT_CACHE
- register vm_object_t o;
+ (void) memory_object_init(pager,
+ object->pager_control,
+ PAGE_SIZE);
- queue_iterate(&vm_object_cached_list, o, vm_object_t, cached_list) {
- if (object == o) {
- return TRUE;
+ vm_object_lock(object);
+ if (named)
+ object->named = TRUE;
+ if (internal) {
+ vm_object_lock_assert_exclusive(object);
+ object->pager_ready = TRUE;
+ vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY);
}
- }
-#endif
- return FALSE;
-}
-#if MACH_PAGEMAP
-/*
- * vm_external_print: [ debug ]
- */
-void
-vm_external_print(
- vm_external_map_t emap,
- vm_object_size_t size)
-{
- if (emap == VM_EXTERNAL_NULL) {
- printf("0 ");
+ object->pager_initialized = TRUE;
+ vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED);
} else {
- vm_object_size_t existence_size = stob(size);
- printf("{ size=%lld, map=[", (uint64_t) existence_size);
- if (existence_size > 0) {
- print_bitstring(emap[0]);
- }
- if (existence_size > 1) {
- print_bitstring(emap[1]);
- }
- if (existence_size > 2) {
- printf("...");
- print_bitstring(emap[existence_size-1]);
- }
- printf("] }\n");
+ vm_object_lock(object);
}
- return;
-}
-#endif /* MACH_PAGEMAP */
-
-int
-vm_follow_object(
- vm_object_t object)
-{
- int count = 0;
- int orig_db_indent = db_indent;
- while (TRUE) {
- if (object == VM_OBJECT_NULL) {
- db_indent = orig_db_indent;
- return count;
- }
-
- count += 1;
+ /*
+ * [At this point, the object must be locked]
+ */
- iprintf("object 0x%x", object);
- printf(", shadow=0x%x", object->shadow);
- printf(", copy=0x%x", object->copy);
- printf(", pager=0x%x", object->pager);
- printf(", ref=%d\n", object->ref_count);
+ /*
+ * Wait for the work above to be done by the first
+ * thread to map this object.
+ */
- db_indent += 2;
- object = object->shadow;
+ while (!object->pager_initialized) {
+ vm_object_sleep(object,
+ VM_OBJECT_EVENT_INITIALIZED,
+ THREAD_UNINT);
}
+ vm_object_unlock(object);
+ XPR(XPR_VM_OBJECT,
+ "vm_object_enter: vm_object %x, memory_object %x, internal %d\n",
+ object, object->pager, internal, 0,0);
+ return(object);
}
/*
- * vm_object_print: [ debug ]
+ * Routine: vm_object_compressor_pager_create
+ * Purpose:
+ * Create a memory object for an internal object.
+ * In/out conditions:
+ * The object is locked on entry and exit;
+ * it may be unlocked within this call.
+ * Limitations:
+ * Only one thread may be performing a
+ * vm_object_compressor_pager_create on an object at
+ * a time. Presumably, only the pageout
+ * daemon will be using this routine.
*/
+
void
-vm_object_print(db_expr_t db_addr, __unused boolean_t have_addr,
- __unused db_expr_t arg_count, __unused char *modif)
+vm_object_compressor_pager_create(
+ vm_object_t object)
{
- vm_object_t object;
- register vm_page_t p;
- const char *s;
-
- register int count;
+ memory_object_t pager;
+ vm_object_hash_entry_t entry;
+ lck_mtx_t *lck;
+ vm_object_t pager_object = VM_OBJECT_NULL;
- object = (vm_object_t) (long) db_addr;
- if (object == VM_OBJECT_NULL)
- return;
+ assert(object != kernel_object);
- iprintf("object 0x%x\n", object);
+ /*
+ * Prevent collapse or termination by holding a paging reference
+ */
- db_indent += 2;
+ vm_object_paging_begin(object);
+ if (object->pager_created) {
+ /*
+ * Someone else got to it first...
+ * wait for them to finish initializing the ports
+ */
+ while (!object->pager_initialized) {
+ vm_object_sleep(object,
+ VM_OBJECT_EVENT_INITIALIZED,
+ THREAD_UNINT);
+ }
+ vm_object_paging_end(object);
+ return;
+ }
- iprintf("size=0x%x", object->size);
- printf(", memq_hint=%p", object->memq_hint);
- printf(", ref_count=%d\n", object->ref_count);
- iprintf("");
-#if TASK_SWAPPER
- printf("res_count=%d, ", object->res_count);
-#endif /* TASK_SWAPPER */
- printf("resident_page_count=%d\n", object->resident_page_count);
+ /*
+ * Indicate that a memory object has been assigned
+ * before dropping the lock, to prevent a race.
+ */
- iprintf("shadow=0x%x", object->shadow);
- if (object->shadow) {
- register int i = 0;
- vm_object_t shadow = object;
- while((shadow = shadow->shadow))
- i++;
- printf(" (depth %d)", i);
- }
- printf(", copy=0x%x", object->copy);
- printf(", shadow_offset=0x%x", object->shadow_offset);
- printf(", last_alloc=0x%x\n", object->last_alloc);
-
- iprintf("pager=0x%x", object->pager);
- printf(", paging_offset=0x%x", object->paging_offset);
- printf(", pager_control=0x%x\n", object->pager_control);
-
- iprintf("copy_strategy=%d[", object->copy_strategy);
- switch (object->copy_strategy) {
- case MEMORY_OBJECT_COPY_NONE:
- printf("copy_none");
- break;
+ object->pager_created = TRUE;
+ object->paging_offset = 0;
+
+ vm_object_unlock(object);
- case MEMORY_OBJECT_COPY_CALL:
- printf("copy_call");
- break;
+ if ((uint32_t) (object->vo_size/PAGE_SIZE) !=
+ (object->vo_size/PAGE_SIZE)) {
+ panic("vm_object_compressor_pager_create(%p): "
+ "object size 0x%llx >= 0x%llx\n",
+ object,
+ (uint64_t) object->vo_size,
+ 0x0FFFFFFFFULL*PAGE_SIZE);
+ }
- case MEMORY_OBJECT_COPY_DELAY:
- printf("copy_delay");
- break;
+ /*
+ * Create the [internal] pager, and associate it with this object.
+ *
+ * We make the association here so that vm_object_enter()
+ * can look up the object to complete initializing it. No
+ * user will ever map this object.
+ */
+ {
+ assert(object->temporary);
- case MEMORY_OBJECT_COPY_SYMMETRIC:
- printf("copy_symmetric");
- break;
+ /* create our new memory object */
+ assert((uint32_t) (object->vo_size/PAGE_SIZE) ==
+ (object->vo_size/PAGE_SIZE));
+ (void) compressor_memory_object_create(
+ (memory_object_size_t) object->vo_size,
+ &pager);
+ if (pager == NULL) {
+ panic("vm_object_compressor_pager_create(): "
+ "no pager for object %p size 0x%llx\n",
+ object, (uint64_t) object->vo_size);
+ }
+ }
- case MEMORY_OBJECT_COPY_INVALID:
- printf("copy_invalid");
- break;
+ entry = vm_object_hash_entry_alloc(pager);
- default:
- printf("?");
- }
- printf("]");
-
- iprintf("all_wanted=0x%x<", object->all_wanted);
- s = "";
- if (vm_object_wanted(object, VM_OBJECT_EVENT_INITIALIZED)) {
- printf("%sinit", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_PAGER_READY)) {
- printf("%sready", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_PAGING_IN_PROGRESS)) {
- printf("%spaging", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_LOCK_IN_PROGRESS)) {
- printf("%slock", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_UNCACHING)) {
- printf("%suncaching", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_COPY_CALL)) {
- printf("%scopy_call", s);
- s = ",";
- }
- if (vm_object_wanted(object, VM_OBJECT_EVENT_CACHING)) {
- printf("%scaching", s);
- s = ",";
- }
- printf(">");
- printf(", paging_in_progress=%d\n", object->paging_in_progress);
- printf(", activity_in_progress=%d\n", object->activity_in_progress);
-
- iprintf("%screated, %sinit, %sready, %spersist, %strusted, %spageout, %s, %s\n",
- (object->pager_created ? "" : "!"),
- (object->pager_initialized ? "" : "!"),
- (object->pager_ready ? "" : "!"),
- (object->can_persist ? "" : "!"),
- (object->pager_trusted ? "" : "!"),
- (object->pageout ? "" : "!"),
- (object->internal ? "internal" : "external"),
- (object->temporary ? "temporary" : "permanent"));
- iprintf("%salive, %spurgeable, %spurgeable_volatile, %spurgeable_empty, %sshadowed, %scached, %sprivate\n",
- (object->alive ? "" : "!"),
- ((object->purgable != VM_PURGABLE_DENY) ? "" : "!"),
- ((object->purgable == VM_PURGABLE_VOLATILE) ? "" : "!"),
- ((object->purgable == VM_PURGABLE_EMPTY) ? "" : "!"),
- (object->shadowed ? "" : "!"),
- (vm_object_cached(object) ? "" : "!"),
- (object->private ? "" : "!"));
- iprintf("%sadvisory_pageout, %ssilent_overwrite\n",
- (object->advisory_pageout ? "" : "!"),
- (object->silent_overwrite ? "" : "!"));
-
-#if MACH_PAGEMAP
- iprintf("existence_map=");
- vm_external_print(object->existence_map, object->size);
-#endif /* MACH_PAGEMAP */
-#if MACH_ASSERT
- iprintf("paging_object=0x%x\n", object->paging_object);
-#endif /* MACH_ASSERT */
+ vm_object_lock(object);
+ lck = vm_object_hash_lock_spin(pager);
+ vm_object_hash_insert(entry, object);
+ vm_object_hash_unlock(lck);
+ vm_object_unlock(object);
- if (vm_object_print_pages) {
- count = 0;
- p = (vm_page_t) queue_first(&object->memq);
- while (!queue_end(&object->memq, (queue_entry_t) p)) {
- if (count == 0) {
- iprintf("memory:=");
- } else if (count == 2) {
- printf("\n");
- iprintf(" ...");
- count = 0;
- } else {
- printf(",");
- }
- count++;
+ /*
+ * A reference was returned by
+ * memory_object_create(), and it is
+ * copied by vm_object_enter().
+ */
- printf("(off=0x%llX,page=%p)", p->offset, p);
- p = (vm_page_t) queue_next(&p->listq);
- }
- if (count != 0) {
- printf("\n");
- }
+ pager_object = vm_object_enter(pager, object->vo_size, TRUE, TRUE, FALSE);
+
+ if (pager_object != object) {
+ panic("vm_object_compressor_pager_create: mismatch (pager: %p, pager_object: %p, orig_object: %p, orig_object size: 0x%llx)\n", pager, pager_object, object, (uint64_t) object->vo_size);
}
- db_indent -= 2;
-}
+ /*
+ * Drop the reference we were passed.
+ */
+ memory_object_deallocate(pager);
+
+ vm_object_lock(object);
+
+ /*
+ * Release the paging reference
+ */
+ vm_object_paging_end(object);
+}
/*
- * vm_object_find [ debug ]
- *
- * Find all tasks which reference the given vm_object.
+ * Routine: vm_object_remove
+ * Purpose:
+ * Eliminate the pager/object association
+ * for this pager.
+ * Conditions:
+ * The object cache must be locked.
*/
-
-boolean_t vm_object_find(vm_object_t object);
-boolean_t vm_object_print_verbose = FALSE;
-
-boolean_t
-vm_object_find(
- vm_object_t object)
+__private_extern__ void
+vm_object_remove(
+ vm_object_t object)
{
- task_t task;
- vm_map_t map;
- vm_map_entry_t entry;
- boolean_t found = FALSE;
-
- queue_iterate(&tasks, task, task_t, tasks) {
- map = task->map;
- for (entry = vm_map_first_entry(map);
- entry && entry != vm_map_to_entry(map);
- entry = entry->vme_next) {
-
- vm_object_t obj;
-
- /*
- * For the time being skip submaps,
- * only the kernel can have submaps,
- * and unless we are interested in
- * kernel objects, we can simply skip
- * submaps. See sb/dejan/nmk18b7/src/mach_kernel/vm
- * for a full solution.
- */
- if (entry->is_sub_map)
- continue;
- if (entry)
- obj = entry->object.vm_object;
- else
- continue;
+ memory_object_t pager;
- while (obj != VM_OBJECT_NULL) {
- if (obj == object) {
- if (!found) {
- printf("TASK\t\tMAP\t\tENTRY\n");
- found = TRUE;
- }
- printf("0x%x\t0x%x\t0x%x\n",
- task, map, entry);
- }
- obj = obj->shadow;
- }
- }
+ if ((pager = object->pager) != MEMORY_OBJECT_NULL) {
+ vm_object_hash_entry_t entry;
+
+ entry = vm_object_hash_lookup(pager, FALSE);
+ if (entry != VM_OBJECT_HASH_ENTRY_NULL)
+ entry->object = VM_OBJECT_NULL;
}
- return(found);
}
-#endif /* MACH_KDB */
+/*
+ * Global variables for vm_object_collapse():
+ *
+ * Counts for normal collapses and bypasses.
+ * Debugging variables, to watch or disable collapse.
+ */
+static long object_collapses = 0;
+static long object_bypasses = 0;
-kern_return_t
-vm_object_populate_with_private(
- vm_object_t object,
- vm_object_offset_t offset,
- ppnum_t phys_page,
- vm_size_t size)
-{
- ppnum_t base_page;
- vm_object_offset_t base_offset;
+static boolean_t vm_object_collapse_allowed = TRUE;
+static boolean_t vm_object_bypass_allowed = TRUE;
+unsigned long vm_object_collapse_encrypted = 0;
- if(!object->private)
- return KERN_FAILURE;
+void vm_object_do_collapse_compressor(vm_object_t object,
+ vm_object_t backing_object);
+void
+vm_object_do_collapse_compressor(
+ vm_object_t object,
+ vm_object_t backing_object)
+{
+ vm_object_offset_t new_offset, backing_offset;
+ vm_object_size_t size;
- base_page = phys_page;
+ vm_counters.do_collapse_compressor++;
- vm_object_lock(object);
- if(!object->phys_contiguous) {
- vm_page_t m;
- if((base_offset = trunc_page_64(offset)) != offset) {
- vm_object_unlock(object);
- return KERN_FAILURE;
- }
- base_offset += object->paging_offset;
- while(size) {
- m = vm_page_lookup(object, base_offset);
- if(m != VM_PAGE_NULL) {
- if(m->fictitious) {
- if (m->phys_page != vm_page_guard_addr) {
+ vm_object_lock_assert_exclusive(object);
+ vm_object_lock_assert_exclusive(backing_object);
- vm_page_lockspin_queues();
- m->private = TRUE;
- vm_page_unlock_queues();
+ size = object->vo_size;
- m->fictitious = FALSE;
- m->phys_page = base_page;
- if(!m->busy) {
- m->busy = TRUE;
- }
- if(!m->absent) {
- m->absent = TRUE;
- }
- m->list_req_pending = TRUE;
- }
- } else if (m->phys_page != base_page) {
- if (m->pmapped) {
- /*
- * pmap call to clear old mapping
- */
- pmap_disconnect(m->phys_page);
- }
- m->phys_page = base_page;
- }
+ /*
+ * Move all compressed pages from backing_object
+ * to the parent.
+ */
- /*
- * ENCRYPTED SWAP:
- * We're not pointing to the same
- * physical page any longer and the
- * contents of the new one are not
- * supposed to be encrypted.
- * XXX What happens to the original
- * physical page. Is it lost ?
- */
- m->encrypted = FALSE;
+ for (backing_offset = object->vo_shadow_offset;
+ backing_offset < object->vo_shadow_offset + object->vo_size;
+ backing_offset += PAGE_SIZE) {
+ memory_object_offset_t backing_pager_offset;
+
+ /* find the next compressed page at or after this offset */
+ backing_pager_offset = (backing_offset +
+ backing_object->paging_offset);
+ backing_pager_offset = vm_compressor_pager_next_compressed(
+ backing_object->pager,
+ backing_pager_offset);
+ if (backing_pager_offset == (memory_object_offset_t) -1) {
+ /* no more compressed pages */
+ break;
+ }
+ backing_offset = (backing_pager_offset -
+ backing_object->paging_offset);
- } else {
- while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL)
- vm_page_more_fictitious();
+ new_offset = backing_offset - object->vo_shadow_offset;
- /*
- * private normally requires lock_queues but since we
- * are initializing the page, its not necessary here
- */
- m->private = TRUE;
- m->fictitious = FALSE;
- m->phys_page = base_page;
- m->list_req_pending = TRUE;
- m->absent = TRUE;
- m->unusual = TRUE;
+ if (new_offset >= object->vo_size) {
+ /* we're out of the scope of "object": done */
+ break;
+ }
- vm_page_insert(m, object, base_offset);
- }
- base_page++; /* Go to the next physical page */
- base_offset += PAGE_SIZE;
- size -= PAGE_SIZE;
+ if ((vm_page_lookup(object, new_offset) != VM_PAGE_NULL) ||
+ (vm_compressor_pager_state_get(object->pager,
+ (new_offset +
+ object->paging_offset)) ==
+ VM_EXTERNAL_STATE_EXISTS)) {
+ /*
+ * This page already exists in object, resident or
+ * compressed.
+ * We don't need this compressed page in backing_object
+ * and it will be reclaimed when we release
+ * backing_object.
+ */
+ continue;
}
- } else {
- /* NOTE: we should check the original settings here */
- /* if we have a size > zero a pmap call should be made */
- /* to disable the range */
- /* pmap_? */
-
- /* shadows on contiguous memory are not allowed */
- /* we therefore can use the offset field */
- object->shadow_offset = (vm_object_offset_t)phys_page << PAGE_SHIFT;
- object->size = size;
+ /*
+ * backing_object has this page in the VM compressor and
+ * we need to transfer it to object.
+ */
+ vm_counters.do_collapse_compressor_pages++;
+ vm_compressor_pager_transfer(
+ /* destination: */
+ object->pager,
+ (new_offset + object->paging_offset),
+ /* source: */
+ backing_object->pager,
+ (backing_offset + backing_object->paging_offset));
}
- vm_object_unlock(object);
- return KERN_SUCCESS;
}
/*
- * memory_object_free_from_cache:
- *
- * Walk the vm_object cache list, removing and freeing vm_objects
- * which are backed by the pager identified by the caller, (pager_ops).
- * Remove up to "count" objects, if there are that may available
- * in the cache.
+ * Routine: vm_object_do_collapse
+ * Purpose:
+ * Collapse an object with the object backing it.
+ * Pages in the backing object are moved into the
+ * parent, and the backing object is deallocated.
+ * Conditions:
+ * Both objects and the cache are locked; the page
+ * queues are unlocked.
*
- * Walk the list at most once, return the number of vm_objects
- * actually freed.
*/
-
-__private_extern__ kern_return_t
-memory_object_free_from_cache(
- __unused host_t host,
- __unused memory_object_pager_ops_t pager_ops,
- int *count)
+static void
+vm_object_do_collapse(
+ vm_object_t object,
+ vm_object_t backing_object)
{
-#if VM_OBJECT_CACHE
- int object_released = 0;
-
- register vm_object_t object = VM_OBJECT_NULL;
- vm_object_t shadow;
+ vm_page_t p, pp;
+ vm_object_offset_t new_offset, backing_offset;
+ vm_object_size_t size;
-/*
- if(host == HOST_NULL)
- return(KERN_INVALID_ARGUMENT);
-*/
+ vm_object_lock_assert_exclusive(object);
+ vm_object_lock_assert_exclusive(backing_object);
- try_again:
- vm_object_cache_lock();
+ assert(object->purgable == VM_PURGABLE_DENY);
+ assert(backing_object->purgable == VM_PURGABLE_DENY);
- queue_iterate(&vm_object_cached_list, object,
- vm_object_t, cached_list) {
- if (object->pager &&
- (pager_ops == object->pager->mo_pager_ops)) {
- vm_object_lock(object);
- queue_remove(&vm_object_cached_list, object,
- vm_object_t, cached_list);
- vm_object_cached_count--;
+ backing_offset = object->vo_shadow_offset;
+ size = object->vo_size;
- vm_object_cache_unlock();
- /*
- * Since this object is in the cache, we know
- * that it is initialized and has only a pager's
- * (implicit) reference. Take a reference to avoid
- * recursive deallocations.
- */
-
- assert(object->pager_initialized);
- assert(object->ref_count == 0);
- vm_object_lock_assert_exclusive(object);
- object->ref_count++;
+ /*
+ * Move all in-memory pages from backing_object
+ * to the parent. Pages that have been paged out
+ * will be overwritten by any of the parent's
+ * pages that shadow them.
+ */
+
+ while (!vm_page_queue_empty(&backing_object->memq)) {
+
+ p = (vm_page_t) vm_page_queue_first(&backing_object->memq);
+
+ new_offset = (p->offset - backing_offset);
+
+ assert(!p->busy || p->absent);
+ /*
+ * If the parent has a page here, or if
+ * this page falls outside the parent,
+ * dispose of it.
+ *
+ * Otherwise, move it as planned.
+ */
+
+ if (p->offset < backing_offset || new_offset >= size) {
+ VM_PAGE_FREE(p);
+ } else {
/*
- * Terminate the object.
- * If the object had a shadow, we let
- * vm_object_deallocate deallocate it.
- * "pageout" objects have a shadow, but
- * maintain a "paging reference" rather
- * than a normal reference.
- * (We are careful here to limit recursion.)
- */
- shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
+ * ENCRYPTED SWAP:
+ * The encryption key includes the "pager" and the
+ * "paging_offset". These will not change during the
+ * object collapse, so we can just move an encrypted
+ * page from one object to the other in this case.
+ * We can't decrypt the page here, since we can't drop
+ * the object lock.
+ */
+ if (p->encrypted) {
+ vm_object_collapse_encrypted++;
+ }
+ pp = vm_page_lookup(object, new_offset);
+ if (pp == VM_PAGE_NULL) {
- if ((vm_object_terminate(object) == KERN_SUCCESS)
- && (shadow != VM_OBJECT_NULL)) {
- vm_object_deallocate(shadow);
+ if (VM_COMPRESSOR_PAGER_STATE_GET(object,
+ new_offset)
+ == VM_EXTERNAL_STATE_EXISTS) {
+ /*
+ * Parent object has this page
+ * in the VM compressor.
+ * Throw away the backing
+ * object's page.
+ */
+ VM_PAGE_FREE(p);
+ } else {
+ /*
+ * Parent now has no page.
+ * Move the backing object's page
+ * up.
+ */
+ vm_page_rename(p, object, new_offset,
+ TRUE);
+ }
+ } else {
+ assert(! pp->absent);
+
+ /*
+ * Parent object has a real page.
+ * Throw away the backing object's
+ * page.
+ */
+ VM_PAGE_FREE(p);
}
-
- if(object_released++ == *count)
- return KERN_SUCCESS;
- goto try_again;
}
}
- vm_object_cache_unlock();
- *count = object_released;
-#else
- *count = 0;
-#endif
- return KERN_SUCCESS;
-}
+ if (vm_object_collapse_compressor_allowed &&
+ object->pager != MEMORY_OBJECT_NULL &&
+ backing_object->pager != MEMORY_OBJECT_NULL) {
+ /* move compressed pages from backing_object to object */
+ vm_object_do_collapse_compressor(object, backing_object);
-kern_return_t
-memory_object_create_named(
- memory_object_t pager,
- memory_object_offset_t size,
- memory_object_control_t *control)
-{
- vm_object_t object;
- vm_object_hash_entry_t entry;
- lck_mtx_t *lck;
+ } else if (backing_object->pager != MEMORY_OBJECT_NULL) {
+ vm_object_hash_entry_t entry;
- *control = MEMORY_OBJECT_CONTROL_NULL;
- if (pager == MEMORY_OBJECT_NULL)
- return KERN_INVALID_ARGUMENT;
+ assert((!object->pager_created &&
+ (object->pager == MEMORY_OBJECT_NULL)) ||
+ (!backing_object->pager_created &&
+ (backing_object->pager == MEMORY_OBJECT_NULL)));
+ /*
+ * Move the pager from backing_object to object.
+ *
+ * XXX We're only using part of the paging space
+ * for keeps now... we ought to discard the
+ * unused portion.
+ */
- lck = vm_object_hash_lock_spin(pager);
- entry = vm_object_hash_lookup(pager, FALSE);
+ assert(!object->paging_in_progress);
+ assert(!object->activity_in_progress);
+ assert(!object->pager_created);
+ assert(object->pager == NULL);
+ object->pager = backing_object->pager;
- if ((entry != VM_OBJECT_HASH_ENTRY_NULL) &&
- (entry->object != VM_OBJECT_NULL)) {
- if (entry->object->named == TRUE)
- panic("memory_object_create_named: caller already holds the right"); }
- vm_object_hash_unlock(lck);
+ if (backing_object->hashed) {
+ lck_mtx_t *lck;
- if ((object = vm_object_enter(pager, size, FALSE, FALSE, TRUE)) == VM_OBJECT_NULL) {
- return(KERN_INVALID_OBJECT);
+ lck = vm_object_hash_lock_spin(backing_object->pager);
+ entry = vm_object_hash_lookup(object->pager, FALSE);
+ assert(entry != VM_OBJECT_HASH_ENTRY_NULL);
+ entry->object = object;
+ vm_object_hash_unlock(lck);
+
+ object->hashed = TRUE;
+ }
+ object->pager_created = backing_object->pager_created;
+ object->pager_control = backing_object->pager_control;
+ object->pager_ready = backing_object->pager_ready;
+ object->pager_initialized = backing_object->pager_initialized;
+ object->paging_offset =
+ backing_object->paging_offset + backing_offset;
+ if (object->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
+ memory_object_control_collapse(object->pager_control,
+ object);
+ }
+ /* the backing_object has lost its pager: reset all fields */
+ backing_object->pager_created = FALSE;
+ backing_object->pager_control = NULL;
+ backing_object->pager_ready = FALSE;
+ backing_object->paging_offset = 0;
+ backing_object->pager = NULL;
}
+ /*
+ * Object now shadows whatever backing_object did.
+ * Note that the reference to backing_object->shadow
+ * moves from within backing_object to within object.
+ */
- /* wait for object (if any) to be ready */
- if (object != VM_OBJECT_NULL) {
- vm_object_lock(object);
- object->named = TRUE;
- while (!object->pager_ready) {
- vm_object_sleep(object,
- VM_OBJECT_EVENT_PAGER_READY,
- THREAD_UNINT);
+ assert(!object->phys_contiguous);
+ assert(!backing_object->phys_contiguous);
+ object->shadow = backing_object->shadow;
+ if (object->shadow) {
+ object->vo_shadow_offset += backing_object->vo_shadow_offset;
+ /* "backing_object" gave its shadow to "object" */
+ backing_object->shadow = VM_OBJECT_NULL;
+ backing_object->vo_shadow_offset = 0;
+ } else {
+ /* no shadow, therefore no shadow offset... */
+ object->vo_shadow_offset = 0;
+ }
+ assert((object->shadow == VM_OBJECT_NULL) ||
+ (object->shadow->copy != backing_object));
+
+ /*
+ * Discard backing_object.
+ *
+ * Since the backing object has no pages, no
+ * pager left, and no object references within it,
+ * all that is necessary is to dispose of it.
+ */
+ object_collapses++;
+
+ assert(backing_object->ref_count == 1);
+ assert(backing_object->resident_page_count == 0);
+ assert(backing_object->paging_in_progress == 0);
+ assert(backing_object->activity_in_progress == 0);
+ assert(backing_object->shadow == VM_OBJECT_NULL);
+ assert(backing_object->vo_shadow_offset == 0);
+
+ if (backing_object->pager != MEMORY_OBJECT_NULL) {
+ /* ... unless it has a pager; need to terminate pager too */
+ vm_counters.do_collapse_terminate++;
+ if (vm_object_terminate(backing_object) != KERN_SUCCESS) {
+ vm_counters.do_collapse_terminate_failure++;
}
- *control = object->pager_control;
- vm_object_unlock(object);
+ return;
}
- return (KERN_SUCCESS);
-}
+ assert(backing_object->pager == NULL);
-/*
- * Routine: memory_object_recover_named [user interface]
- * Purpose:
- * Attempt to recover a named reference for a VM object.
- * VM will verify that the object has not already started
- * down the termination path, and if it has, will optionally
- * wait for that to finish.
- * Returns:
- * KERN_SUCCESS - we recovered a named reference on the object
- * KERN_FAILURE - we could not recover a reference (object dead)
- * KERN_INVALID_ARGUMENT - bad memory object control
- */
-kern_return_t
-memory_object_recover_named(
- memory_object_control_t control,
- boolean_t wait_on_terminating)
-{
- vm_object_t object;
+ backing_object->alive = FALSE;
+ vm_object_unlock(backing_object);
- object = memory_object_control_to_vm_object(control);
- if (object == VM_OBJECT_NULL) {
- return (KERN_INVALID_ARGUMENT);
- }
-restart:
- vm_object_lock(object);
+ XPR(XPR_VM_OBJECT, "vm_object_collapse, collapsed 0x%X\n",
+ backing_object, 0,0,0,0);
- if (object->terminating && wait_on_terminating) {
- vm_object_wait(object,
- VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
- THREAD_UNINT);
- goto restart;
+#if VM_OBJECT_TRACKING
+ if (vm_object_tracking_inited) {
+ btlog_remove_entries_for_element(vm_object_tracking_btlog,
+ backing_object);
}
+#endif /* VM_OBJECT_TRACKING */
- if (!object->alive) {
- vm_object_unlock(object);
- return KERN_FAILURE;
- }
+ vm_object_lock_destroy(backing_object);
- if (object->named == TRUE) {
- vm_object_unlock(object);
- return KERN_SUCCESS;
- }
-#if VM_OBJECT_CACHE
- if ((object->ref_count == 0) && (!object->terminating)) {
- if (!vm_object_cache_lock_try()) {
- vm_object_unlock(object);
- goto restart;
- }
- queue_remove(&vm_object_cached_list, object,
- vm_object_t, cached_list);
- vm_object_cached_count--;
- XPR(XPR_VM_OBJECT_CACHE,
- "memory_object_recover_named: removing %X, head (%X, %X)\n",
- object,
- vm_object_cached_list.next,
- vm_object_cached_list.prev, 0,0);
-
- vm_object_cache_unlock();
- }
-#endif
- object->named = TRUE;
- vm_object_lock_assert_exclusive(object);
- object->ref_count++;
- vm_object_res_reference(object);
- while (!object->pager_ready) {
- vm_object_sleep(object,
- VM_OBJECT_EVENT_PAGER_READY,
- THREAD_UNINT);
- }
- vm_object_unlock(object);
- return (KERN_SUCCESS);
+ zfree(vm_object_zone, backing_object);
+
}
+static void
+vm_object_do_bypass(
+ vm_object_t object,
+ vm_object_t backing_object)
+{
+ /*
+ * Make the parent shadow the next object
+ * in the chain.
+ */
+
+ vm_object_lock_assert_exclusive(object);
+ vm_object_lock_assert_exclusive(backing_object);
-/*
- * vm_object_release_name:
- *
- * Enforces name semantic on memory_object reference count decrement
- * This routine should not be called unless the caller holds a name
- * reference gained through the memory_object_create_named.
- *
- * If the TERMINATE_IDLE flag is set, the call will return if the
- * reference count is not 1. i.e. idle with the only remaining reference
- * being the name.
- * If the decision is made to proceed the name field flag is set to
- * false and the reference count is decremented. If the RESPECT_CACHE
- * flag is set and the reference count has gone to zero, the
- * memory_object is checked to see if it is cacheable otherwise when
- * the reference count is zero, it is simply terminated.
- */
-
-__private_extern__ kern_return_t
-vm_object_release_name(
- vm_object_t object,
- int flags)
-{
- vm_object_t shadow;
- boolean_t original_object = TRUE;
-
- while (object != VM_OBJECT_NULL) {
-
- vm_object_lock(object);
+#if TASK_SWAPPER
+ /*
+ * Do object reference in-line to
+ * conditionally increment shadow's
+ * residence count. If object is not
+ * resident, leave residence count
+ * on shadow alone.
+ */
+ if (backing_object->shadow != VM_OBJECT_NULL) {
+ vm_object_lock(backing_object->shadow);
+ vm_object_lock_assert_exclusive(backing_object->shadow);
+ backing_object->shadow->ref_count++;
+ if (object->res_count != 0)
+ vm_object_res_reference(backing_object->shadow);
+ vm_object_unlock(backing_object->shadow);
+ }
+#else /* TASK_SWAPPER */
+ vm_object_reference(backing_object->shadow);
+#endif /* TASK_SWAPPER */
- assert(object->alive);
- if (original_object)
- assert(object->named);
- assert(object->ref_count > 0);
+ assert(!object->phys_contiguous);
+ assert(!backing_object->phys_contiguous);
+ object->shadow = backing_object->shadow;
+ if (object->shadow) {
+ object->vo_shadow_offset += backing_object->vo_shadow_offset;
+ } else {
+ /* no shadow, therefore no shadow offset... */
+ object->vo_shadow_offset = 0;
+ }
+
+ /*
+ * Backing object might have had a copy pointer
+ * to us. If it did, clear it.
+ */
+ if (backing_object->copy == object) {
+ backing_object->copy = VM_OBJECT_NULL;
+ }
+
+ /*
+ * Drop the reference count on backing_object.
+#if TASK_SWAPPER
+ * Since its ref_count was at least 2, it
+ * will not vanish; so we don't need to call
+ * vm_object_deallocate.
+ * [with a caveat for "named" objects]
+ *
+ * The res_count on the backing object is
+ * conditionally decremented. It's possible
+ * (via vm_pageout_scan) to get here with
+ * a "swapped" object, which has a 0 res_count,
+ * in which case, the backing object res_count
+ * is already down by one.
+#else
+ * Don't call vm_object_deallocate unless
+ * ref_count drops to zero.
+ *
+ * The ref_count can drop to zero here if the
+ * backing object could be bypassed but not
+ * collapsed, such as when the backing object
+ * is temporary and cachable.
+#endif
+ */
+ if (backing_object->ref_count > 2 ||
+ (!backing_object->named && backing_object->ref_count > 1)) {
+ vm_object_lock_assert_exclusive(backing_object);
+ backing_object->ref_count--;
+#if TASK_SWAPPER
+ if (object->res_count != 0)
+ vm_object_res_deallocate(backing_object);
+ assert(backing_object->ref_count > 0);
+#endif /* TASK_SWAPPER */
+ vm_object_unlock(backing_object);
+ } else {
/*
- * We have to wait for initialization before
- * destroying or caching the object.
+ * Drop locks so that we can deallocate
+ * the backing object.
*/
- if (object->pager_created && !object->pager_initialized) {
- assert(!object->can_persist);
- vm_object_assert_wait(object,
- VM_OBJECT_EVENT_INITIALIZED,
- THREAD_UNINT);
- vm_object_unlock(object);
- thread_block(THREAD_CONTINUE_NULL);
- continue;
+#if TASK_SWAPPER
+ if (object->res_count == 0) {
+ /* XXX get a reference for the deallocate below */
+ vm_object_res_reference(backing_object);
}
+#endif /* TASK_SWAPPER */
+ /*
+ * vm_object_collapse (the caller of this function) is
+ * now called from contexts that may not guarantee that a
+ * valid reference is held on the object... w/o a valid
+ * reference, it is unsafe and unwise (you will definitely
+ * regret it) to unlock the object and then retake the lock
+ * since the object may be terminated and recycled in between.
+ * The "activity_in_progress" reference will keep the object
+ * 'stable'.
+ */
+ vm_object_activity_begin(object);
+ vm_object_unlock(object);
- if (((object->ref_count > 1)
- && (flags & MEMORY_OBJECT_TERMINATE_IDLE))
- || (object->terminating)) {
- vm_object_unlock(object);
- return KERN_FAILURE;
- } else {
- if (flags & MEMORY_OBJECT_RELEASE_NO_OP) {
- vm_object_unlock(object);
- return KERN_SUCCESS;
- }
- }
-
- if ((flags & MEMORY_OBJECT_RESPECT_CACHE) &&
- (object->ref_count == 1)) {
- if (original_object)
- object->named = FALSE;
- vm_object_unlock(object);
- /* let vm_object_deallocate push this thing into */
- /* the cache, if that it is where it is bound */
- vm_object_deallocate(object);
- return KERN_SUCCESS;
- }
- VM_OBJ_RES_DECR(object);
- shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
+ vm_object_unlock(backing_object);
+ vm_object_deallocate(backing_object);
- if (object->ref_count == 1) {
- if (vm_object_terminate(object) != KERN_SUCCESS) {
- if (original_object) {
- return KERN_FAILURE;
- } else {
- return KERN_SUCCESS;
- }
- }
- if (shadow != VM_OBJECT_NULL) {
- original_object = FALSE;
- object = shadow;
- continue;
- }
- return KERN_SUCCESS;
- } else {
- vm_object_lock_assert_exclusive(object);
- object->ref_count--;
- assert(object->ref_count > 0);
- if(original_object)
- object->named = FALSE;
- vm_object_unlock(object);
- return KERN_SUCCESS;
- }
+ /*
+ * Relock object. We don't have to reverify
+ * its state since vm_object_collapse will
+ * do that for us as it starts at the
+ * top of its loop.
+ */
+
+ vm_object_lock(object);
+ vm_object_activity_end(object);
}
- /*NOTREACHED*/
- assert(0);
- return KERN_FAILURE;
+
+ object_bypasses++;
}
+
+/*
+ * vm_object_collapse:
+ *
+ * Perform an object collapse or an object bypass if appropriate.
+ * The real work of collapsing and bypassing is performed in
+ * the routines vm_object_do_collapse and vm_object_do_bypass.
+ *
+ * Requires that the object be locked and the page queues be unlocked.
+ *
+ */
+static unsigned long vm_object_collapse_calls = 0;
+static unsigned long vm_object_collapse_objects = 0;
+static unsigned long vm_object_collapse_do_collapse = 0;
+static unsigned long vm_object_collapse_do_bypass = 0;
-__private_extern__ kern_return_t
-vm_object_lock_request(
- vm_object_t object,
- vm_object_offset_t offset,
- vm_object_size_t size,
- memory_object_return_t should_return,
- int flags,
- vm_prot_t prot)
+__private_extern__ void
+vm_object_collapse(
+ vm_object_t object,
+ vm_object_offset_t hint_offset,
+ boolean_t can_bypass)
{
- __unused boolean_t should_flush;
+ vm_object_t backing_object;
+ unsigned int rcount;
+ unsigned int size;
+ vm_object_t original_object;
+ int object_lock_type;
+ int backing_object_lock_type;
- should_flush = flags & MEMORY_OBJECT_DATA_FLUSH;
+ vm_object_collapse_calls++;
- XPR(XPR_MEMORY_OBJECT,
- "vm_o_lock_request, obj 0x%X off 0x%X size 0x%X flags %X prot %X\n",
- object, offset, size,
- (((should_return&1)<<1)|should_flush), prot);
+ if (! vm_object_collapse_allowed &&
+ ! (can_bypass && vm_object_bypass_allowed)) {
+ return;
+ }
- /*
- * Check for bogus arguments.
- */
- if (object == VM_OBJECT_NULL)
- return (KERN_INVALID_ARGUMENT);
+ XPR(XPR_VM_OBJECT, "vm_object_collapse, obj 0x%X\n",
+ object, 0,0,0,0);
- if ((prot & ~VM_PROT_ALL) != 0 && prot != VM_PROT_NO_CHANGE)
- return (KERN_INVALID_ARGUMENT);
+ if (object == VM_OBJECT_NULL)
+ return;
- size = round_page_64(size);
+ original_object = object;
/*
- * Lock the object, and acquire a paging reference to
- * prevent the memory_object reference from being released.
+ * The top object was locked "exclusive" by the caller.
+ * In the first pass, to determine if we can collapse the shadow chain,
+ * take a "shared" lock on the shadow objects. If we can collapse,
+ * we'll have to go down the chain again with exclusive locks.
*/
- vm_object_lock(object);
- vm_object_paging_begin(object);
-
- (void)vm_object_update(object,
- offset, size, NULL, NULL, should_return, flags, prot);
+ object_lock_type = OBJECT_LOCK_EXCLUSIVE;
+ backing_object_lock_type = OBJECT_LOCK_SHARED;
- vm_object_paging_end(object);
- vm_object_unlock(object);
+retry:
+ object = original_object;
+ vm_object_lock_assert_exclusive(object);
- return (KERN_SUCCESS);
-}
+ while (TRUE) {
+ vm_object_collapse_objects++;
+ /*
+ * Verify that the conditions are right for either
+ * collapse or bypass:
+ */
-/*
- * Empty a purgeable object by grabbing the physical pages assigned to it and
- * putting them on the free queue without writing them to backing store, etc.
- * When the pages are next touched they will be demand zero-fill pages. We
- * skip pages which are busy, being paged in/out, wired, etc. We do _not_
- * skip referenced/dirty pages, pages on the active queue, etc. We're more
+ /*
+ * There is a backing object, and
+ */
+
+ backing_object = object->shadow;
+ if (backing_object == VM_OBJECT_NULL) {
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ return;
+ }
+ if (backing_object_lock_type == OBJECT_LOCK_SHARED) {
+ vm_object_lock_shared(backing_object);
+ } else {
+ vm_object_lock(backing_object);
+ }
+
+ /*
+ * No pages in the object are currently
+ * being paged out, and
+ */
+ if (object->paging_in_progress != 0 ||
+ object->activity_in_progress != 0) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * ...
+ * The backing object is not read_only,
+ * and no pages in the backing object are
+ * currently being paged out.
+ * The backing object is internal.
+ *
+ */
+
+ if (!backing_object->internal ||
+ backing_object->paging_in_progress != 0 ||
+ backing_object->activity_in_progress != 0) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * Purgeable objects are not supposed to engage in
+ * copy-on-write activities, so should not have
+ * any shadow objects or be a shadow object to another
+ * object.
+ * Collapsing a purgeable object would require some
+ * updates to the purgeable compressed ledgers.
+ */
+ if (object->purgable != VM_PURGABLE_DENY ||
+ backing_object->purgable != VM_PURGABLE_DENY) {
+ panic("vm_object_collapse() attempting to collapse "
+ "purgeable object: %p(%d) %p(%d)\n",
+ object, object->purgable,
+ backing_object, backing_object->purgable);
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * The backing object can't be a copy-object:
+ * the shadow_offset for the copy-object must stay
+ * as 0. Furthermore (for the 'we have all the
+ * pages' case), if we bypass backing_object and
+ * just shadow the next object in the chain, old
+ * pages from that object would then have to be copied
+ * BOTH into the (former) backing_object and into the
+ * parent object.
+ */
+ if (backing_object->shadow != VM_OBJECT_NULL &&
+ backing_object->shadow->copy == backing_object) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * We can now try to either collapse the backing
+ * object (if the parent is the only reference to
+ * it) or (perhaps) remove the parent's reference
+ * to it.
+ *
+ * If there is exactly one reference to the backing
+ * object, we may be able to collapse it into the
+ * parent.
+ *
+ * As long as one of the objects is still not known
+ * to the pager, we can collapse them.
+ */
+ if (backing_object->ref_count == 1 &&
+ (vm_object_collapse_compressor_allowed ||
+ !object->pager_created
+ || (!backing_object->pager_created)
+ ) && vm_object_collapse_allowed) {
+
+ /*
+ * We need the exclusive lock on the VM objects.
+ */
+ if (backing_object_lock_type != OBJECT_LOCK_EXCLUSIVE) {
+ /*
+ * We have an object and its shadow locked
+ * "shared". We can't just upgrade the locks
+ * to "exclusive", as some other thread might
+ * also have these objects locked "shared" and
+ * attempt to upgrade one or the other to
+ * "exclusive". The upgrades would block
+ * forever waiting for the other "shared" locks
+ * to get released.
+ * So we have to release the locks and go
+ * down the shadow chain again (since it could
+ * have changed) with "exclusive" locking.
+ */
+ vm_object_unlock(backing_object);
+ if (object != original_object)
+ vm_object_unlock(object);
+ object_lock_type = OBJECT_LOCK_EXCLUSIVE;
+ backing_object_lock_type = OBJECT_LOCK_EXCLUSIVE;
+ goto retry;
+ }
+
+ XPR(XPR_VM_OBJECT,
+ "vm_object_collapse: %x to %x, pager %x, pager_control %x\n",
+ backing_object, object,
+ backing_object->pager,
+ backing_object->pager_control, 0);
+
+ /*
+ * Collapse the object with its backing
+ * object, and try again with the object's
+ * new backing object.
+ */
+
+ vm_object_do_collapse(object, backing_object);
+ vm_object_collapse_do_collapse++;
+ continue;
+ }
+
+ /*
+ * Collapsing the backing object was not possible
+ * or permitted, so let's try bypassing it.
+ */
+
+ if (! (can_bypass && vm_object_bypass_allowed)) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+
+ /*
+ * If the object doesn't have all its pages present,
+ * we have to make sure no pages in the backing object
+ * "show through" before bypassing it.
+ */
+ size = (unsigned int)atop(object->vo_size);
+ rcount = object->resident_page_count;
+
+ if (rcount != size) {
+ vm_object_offset_t offset;
+ vm_object_offset_t backing_offset;
+ unsigned int backing_rcount;
+
+ /*
+ * If the backing object has a pager but no pagemap,
+ * then we cannot bypass it, because we don't know
+ * what pages it has.
+ */
+ if (backing_object->pager_created) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * If the object has a pager but no pagemap,
+ * then we cannot bypass it, because we don't know
+ * what pages it has.
+ */
+ if (object->pager_created) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ backing_offset = object->vo_shadow_offset;
+ backing_rcount = backing_object->resident_page_count;
+
+ if ( (int)backing_rcount - (int)(atop(backing_object->vo_size) - size) > (int)rcount) {
+ /*
+ * we have enough pages in the backing object to guarantee that
+ * at least 1 of them must be 'uncovered' by a resident page
+ * in the object we're evaluating, so move on and
+ * try to collapse the rest of the shadow chain
+ */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * If all of the pages in the backing object are
+ * shadowed by the parent object, the parent
+ * object no longer has to shadow the backing
+ * object; it can shadow the next one in the
+ * chain.
+ *
+ * If the backing object has existence info,
+ * we must check examine its existence info
+ * as well.
+ *
+ */
+
+#define EXISTS_IN_OBJECT(obj, off, rc) \
+ ((VM_COMPRESSOR_PAGER_STATE_GET((obj), (off)) \
+ == VM_EXTERNAL_STATE_EXISTS) || \
+ ((rc) && vm_page_lookup((obj), (off)) != VM_PAGE_NULL && (rc)--))
+
+ /*
+ * Check the hint location first
+ * (since it is often the quickest way out of here).
+ */
+ if (object->cow_hint != ~(vm_offset_t)0)
+ hint_offset = (vm_object_offset_t)object->cow_hint;
+ else
+ hint_offset = (hint_offset > 8 * PAGE_SIZE_64) ?
+ (hint_offset - 8 * PAGE_SIZE_64) : 0;
+
+ if (EXISTS_IN_OBJECT(backing_object, hint_offset +
+ backing_offset, backing_rcount) &&
+ !EXISTS_IN_OBJECT(object, hint_offset, rcount)) {
+ /* dependency right at the hint */
+ object->cow_hint = (vm_offset_t) hint_offset; /* atomic */
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+
+ /*
+ * If the object's window onto the backing_object
+ * is large compared to the number of resident
+ * pages in the backing object, it makes sense to
+ * walk the backing_object's resident pages first.
+ *
+ * NOTE: Pages may be in both the existence map and/or
+ * resident, so if we don't find a dependency while
+ * walking the backing object's resident page list
+ * directly, and there is an existence map, we'll have
+ * to run the offset based 2nd pass. Because we may
+ * have to run both passes, we need to be careful
+ * not to decrement 'rcount' in the 1st pass
+ */
+ if (backing_rcount && backing_rcount < (size / 8)) {
+ unsigned int rc = rcount;
+ vm_page_t p;
+
+ backing_rcount = backing_object->resident_page_count;
+ p = (vm_page_t)vm_page_queue_first(&backing_object->memq);
+ do {
+ offset = (p->offset - backing_offset);
+
+ if (offset < object->vo_size &&
+ offset != hint_offset &&
+ !EXISTS_IN_OBJECT(object, offset, rc)) {
+ /* found a dependency */
+ object->cow_hint = (vm_offset_t) offset; /* atomic */
+
+ break;
+ }
+ p = (vm_page_t) vm_page_queue_next(&p->listq);
+
+ } while (--backing_rcount);
+ if (backing_rcount != 0 ) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+ }
+
+ /*
+ * Walk through the offsets looking for pages in the
+ * backing object that show through to the object.
+ */
+ if (backing_rcount) {
+ offset = hint_offset;
+
+ while((offset =
+ (offset + PAGE_SIZE_64 < object->vo_size) ?
+ (offset + PAGE_SIZE_64) : 0) != hint_offset) {
+
+ if (EXISTS_IN_OBJECT(backing_object, offset +
+ backing_offset, backing_rcount) &&
+ !EXISTS_IN_OBJECT(object, offset, rcount)) {
+ /* found a dependency */
+ object->cow_hint = (vm_offset_t) offset; /* atomic */
+ break;
+ }
+ }
+ if (offset != hint_offset) {
+ /* try and collapse the rest of the shadow chain */
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ object = backing_object;
+ object_lock_type = backing_object_lock_type;
+ continue;
+ }
+ }
+ }
+
+ /*
+ * We need "exclusive" locks on the 2 VM objects.
+ */
+ if (backing_object_lock_type != OBJECT_LOCK_EXCLUSIVE) {
+ vm_object_unlock(backing_object);
+ if (object != original_object)
+ vm_object_unlock(object);
+ object_lock_type = OBJECT_LOCK_EXCLUSIVE;
+ backing_object_lock_type = OBJECT_LOCK_EXCLUSIVE;
+ goto retry;
+ }
+
+ /* reset the offset hint for any objects deeper in the chain */
+ object->cow_hint = (vm_offset_t)0;
+
+ /*
+ * All interesting pages in the backing object
+ * already live in the parent or its pager.
+ * Thus we can bypass the backing object.
+ */
+
+ vm_object_do_bypass(object, backing_object);
+ vm_object_collapse_do_bypass++;
+
+ /*
+ * Try again with this object's new backing object.
+ */
+
+ continue;
+ }
+
+ /* NOT REACHED */
+ /*
+ if (object != original_object) {
+ vm_object_unlock(object);
+ }
+ */
+}
+
+/*
+ * Routine: vm_object_page_remove: [internal]
+ * Purpose:
+ * Removes all physical pages in the specified
+ * object range from the object's list of pages.
+ *
+ * In/out conditions:
+ * The object must be locked.
+ * The object must not have paging_in_progress, usually
+ * guaranteed by not having a pager.
+ */
+unsigned int vm_object_page_remove_lookup = 0;
+unsigned int vm_object_page_remove_iterate = 0;
+
+__private_extern__ void
+vm_object_page_remove(
+ vm_object_t object,
+ vm_object_offset_t start,
+ vm_object_offset_t end)
+{
+ vm_page_t p, next;
+
+ /*
+ * One and two page removals are most popular.
+ * The factor of 16 here is somewhat arbitrary.
+ * It balances vm_object_lookup vs iteration.
+ */
+
+ if (atop_64(end - start) < (unsigned)object->resident_page_count/16) {
+ vm_object_page_remove_lookup++;
+
+ for (; start < end; start += PAGE_SIZE_64) {
+ p = vm_page_lookup(object, start);
+ if (p != VM_PAGE_NULL) {
+ assert(!p->cleaning && !p->laundry);
+ if (!p->fictitious && p->pmapped)
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+ VM_PAGE_FREE(p);
+ }
+ }
+ } else {
+ vm_object_page_remove_iterate++;
+
+ p = (vm_page_t) vm_page_queue_first(&object->memq);
+ while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t) p)) {
+ next = (vm_page_t) vm_page_queue_next(&p->listq);
+ if ((start <= p->offset) && (p->offset < end)) {
+ assert(!p->cleaning && !p->laundry);
+ if (!p->fictitious && p->pmapped)
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+ VM_PAGE_FREE(p);
+ }
+ p = next;
+ }
+ }
+}
+
+
+/*
+ * Routine: vm_object_coalesce
+ * Function: Coalesces two objects backing up adjoining
+ * regions of memory into a single object.
+ *
+ * returns TRUE if objects were combined.
+ *
+ * NOTE: Only works at the moment if the second object is NULL -
+ * if it's not, which object do we lock first?
+ *
+ * Parameters:
+ * prev_object First object to coalesce
+ * prev_offset Offset into prev_object
+ * next_object Second object into coalesce
+ * next_offset Offset into next_object
+ *
+ * prev_size Size of reference to prev_object
+ * next_size Size of reference to next_object
+ *
+ * Conditions:
+ * The object(s) must *not* be locked. The map must be locked
+ * to preserve the reference to the object(s).
+ */
+static int vm_object_coalesce_count = 0;
+
+__private_extern__ boolean_t
+vm_object_coalesce(
+ vm_object_t prev_object,
+ vm_object_t next_object,
+ vm_object_offset_t prev_offset,
+ __unused vm_object_offset_t next_offset,
+ vm_object_size_t prev_size,
+ vm_object_size_t next_size)
+{
+ vm_object_size_t newsize;
+
+#ifdef lint
+ next_offset++;
+#endif /* lint */
+
+ if (next_object != VM_OBJECT_NULL) {
+ return(FALSE);
+ }
+
+ if (prev_object == VM_OBJECT_NULL) {
+ return(TRUE);
+ }
+
+ XPR(XPR_VM_OBJECT,
+ "vm_object_coalesce: 0x%X prev_off 0x%X prev_size 0x%X next_size 0x%X\n",
+ prev_object, prev_offset, prev_size, next_size, 0);
+
+ vm_object_lock(prev_object);
+
+ /*
+ * Try to collapse the object first
+ */
+ vm_object_collapse(prev_object, prev_offset, TRUE);
+
+ /*
+ * Can't coalesce if pages not mapped to
+ * prev_entry may be in use any way:
+ * . more than one reference
+ * . paged out
+ * . shadows another object
+ * . has a copy elsewhere
+ * . is purgeable
+ * . paging references (pages might be in page-list)
+ */
+
+ if ((prev_object->ref_count > 1) ||
+ prev_object->pager_created ||
+ (prev_object->shadow != VM_OBJECT_NULL) ||
+ (prev_object->copy != VM_OBJECT_NULL) ||
+ (prev_object->true_share != FALSE) ||
+ (prev_object->purgable != VM_PURGABLE_DENY) ||
+ (prev_object->paging_in_progress != 0) ||
+ (prev_object->activity_in_progress != 0)) {
+ vm_object_unlock(prev_object);
+ return(FALSE);
+ }
+
+ vm_object_coalesce_count++;
+
+ /*
+ * Remove any pages that may still be in the object from
+ * a previous deallocation.
+ */
+ vm_object_page_remove(prev_object,
+ prev_offset + prev_size,
+ prev_offset + prev_size + next_size);
+
+ /*
+ * Extend the object if necessary.
+ */
+ newsize = prev_offset + prev_size + next_size;
+ if (newsize > prev_object->vo_size) {
+ prev_object->vo_size = newsize;
+ }
+
+ vm_object_unlock(prev_object);
+ return(TRUE);
+}
+
+kern_return_t
+vm_object_populate_with_private(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ ppnum_t phys_page,
+ vm_size_t size)
+{
+ ppnum_t base_page;
+ vm_object_offset_t base_offset;
+
+
+ if (!object->private)
+ return KERN_FAILURE;
+
+ base_page = phys_page;
+
+ vm_object_lock(object);
+
+ if (!object->phys_contiguous) {
+ vm_page_t m;
+
+ if ((base_offset = trunc_page_64(offset)) != offset) {
+ vm_object_unlock(object);
+ return KERN_FAILURE;
+ }
+ base_offset += object->paging_offset;
+
+ while (size) {
+ m = vm_page_lookup(object, base_offset);
+
+ if (m != VM_PAGE_NULL) {
+ if (m->fictitious) {
+ if (VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr) {
+
+ vm_page_lockspin_queues();
+ m->private = TRUE;
+ vm_page_unlock_queues();
+
+ m->fictitious = FALSE;
+ VM_PAGE_SET_PHYS_PAGE(m, base_page);
+ }
+ } else if (VM_PAGE_GET_PHYS_PAGE(m) != base_page) {
+
+ if ( !m->private) {
+ /*
+ * we'd leak a real page... that can't be right
+ */
+ panic("vm_object_populate_with_private - %p not private", m);
+ }
+ if (m->pmapped) {
+ /*
+ * pmap call to clear old mapping
+ */
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m));
+ }
+ VM_PAGE_SET_PHYS_PAGE(m, base_page);
+ }
+ if (m->encrypted) {
+ /*
+ * we should never see this on a ficticious or private page
+ */
+ panic("vm_object_populate_with_private - %p encrypted", m);
+ }
+
+ } else {
+ while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL)
+ vm_page_more_fictitious();
+
+ /*
+ * private normally requires lock_queues but since we
+ * are initializing the page, its not necessary here
+ */
+ m->private = TRUE;
+ m->fictitious = FALSE;
+ VM_PAGE_SET_PHYS_PAGE(m, base_page);
+ m->unusual = TRUE;
+ m->busy = FALSE;
+
+ vm_page_insert(m, object, base_offset);
+ }
+ base_page++; /* Go to the next physical page */
+ base_offset += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ }
+ } else {
+ /* NOTE: we should check the original settings here */
+ /* if we have a size > zero a pmap call should be made */
+ /* to disable the range */
+
+ /* pmap_? */
+
+ /* shadows on contiguous memory are not allowed */
+ /* we therefore can use the offset field */
+ object->vo_shadow_offset = (vm_object_offset_t)phys_page << PAGE_SHIFT;
+ object->vo_size = size;
+ }
+ vm_object_unlock(object);
+
+ return KERN_SUCCESS;
+}
+
+/*
+ * memory_object_free_from_cache:
+ *
+ * Walk the vm_object cache list, removing and freeing vm_objects
+ * which are backed by the pager identified by the caller, (pager_ops).
+ * Remove up to "count" objects, if there are that may available
+ * in the cache.
+ *
+ * Walk the list at most once, return the number of vm_objects
+ * actually freed.
+ */
+
+__private_extern__ kern_return_t
+memory_object_free_from_cache(
+ __unused host_t host,
+ __unused memory_object_pager_ops_t pager_ops,
+ int *count)
+{
+#if VM_OBJECT_CACHE
+ int object_released = 0;
+
+ vm_object_t object = VM_OBJECT_NULL;
+ vm_object_t shadow;
+
+/*
+ if(host == HOST_NULL)
+ return(KERN_INVALID_ARGUMENT);
+*/
+
+ try_again:
+ vm_object_cache_lock();
+
+ queue_iterate(&vm_object_cached_list, object,
+ vm_object_t, cached_list) {
+ if (object->pager &&
+ (pager_ops == object->pager->mo_pager_ops)) {
+ vm_object_lock(object);
+ queue_remove(&vm_object_cached_list, object,
+ vm_object_t, cached_list);
+ vm_object_cached_count--;
+
+ vm_object_cache_unlock();
+ /*
+ * Since this object is in the cache, we know
+ * that it is initialized and has only a pager's
+ * (implicit) reference. Take a reference to avoid
+ * recursive deallocations.
+ */
+
+ assert(object->pager_initialized);
+ assert(object->ref_count == 0);
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count++;
+
+ /*
+ * Terminate the object.
+ * If the object had a shadow, we let
+ * vm_object_deallocate deallocate it.
+ * "pageout" objects have a shadow, but
+ * maintain a "paging reference" rather
+ * than a normal reference.
+ * (We are careful here to limit recursion.)
+ */
+ shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
+
+ if ((vm_object_terminate(object) == KERN_SUCCESS)
+ && (shadow != VM_OBJECT_NULL)) {
+ vm_object_deallocate(shadow);
+ }
+
+ if(object_released++ == *count)
+ return KERN_SUCCESS;
+ goto try_again;
+ }
+ }
+ vm_object_cache_unlock();
+ *count = object_released;
+#else
+ *count = 0;
+#endif
+ return KERN_SUCCESS;
+}
+
+
+
+kern_return_t
+memory_object_create_named(
+ memory_object_t pager,
+ memory_object_offset_t size,
+ memory_object_control_t *control)
+{
+ vm_object_t object;
+ vm_object_hash_entry_t entry;
+ lck_mtx_t *lck;
+
+ *control = MEMORY_OBJECT_CONTROL_NULL;
+ if (pager == MEMORY_OBJECT_NULL)
+ return KERN_INVALID_ARGUMENT;
+
+ lck = vm_object_hash_lock_spin(pager);
+ entry = vm_object_hash_lookup(pager, FALSE);
+
+ if ((entry != VM_OBJECT_HASH_ENTRY_NULL) &&
+ (entry->object != VM_OBJECT_NULL)) {
+ if (entry->object->named == TRUE)
+ panic("memory_object_create_named: caller already holds the right"); }
+ vm_object_hash_unlock(lck);
+
+ if ((object = vm_object_enter(pager, size, FALSE, FALSE, TRUE)) == VM_OBJECT_NULL) {
+ return(KERN_INVALID_OBJECT);
+ }
+
+ /* wait for object (if any) to be ready */
+ if (object != VM_OBJECT_NULL) {
+ vm_object_lock(object);
+ object->named = TRUE;
+ while (!object->pager_ready) {
+ vm_object_sleep(object,
+ VM_OBJECT_EVENT_PAGER_READY,
+ THREAD_UNINT);
+ }
+ *control = object->pager_control;
+ vm_object_unlock(object);
+ }
+ return (KERN_SUCCESS);
+}
+
+
+/*
+ * Routine: memory_object_recover_named [user interface]
+ * Purpose:
+ * Attempt to recover a named reference for a VM object.
+ * VM will verify that the object has not already started
+ * down the termination path, and if it has, will optionally
+ * wait for that to finish.
+ * Returns:
+ * KERN_SUCCESS - we recovered a named reference on the object
+ * KERN_FAILURE - we could not recover a reference (object dead)
+ * KERN_INVALID_ARGUMENT - bad memory object control
+ */
+kern_return_t
+memory_object_recover_named(
+ memory_object_control_t control,
+ boolean_t wait_on_terminating)
+{
+ vm_object_t object;
+
+ object = memory_object_control_to_vm_object(control);
+ if (object == VM_OBJECT_NULL) {
+ return (KERN_INVALID_ARGUMENT);
+ }
+restart:
+ vm_object_lock(object);
+
+ if (object->terminating && wait_on_terminating) {
+ vm_object_wait(object,
+ VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
+ THREAD_UNINT);
+ goto restart;
+ }
+
+ if (!object->alive) {
+ vm_object_unlock(object);
+ return KERN_FAILURE;
+ }
+
+ if (object->named == TRUE) {
+ vm_object_unlock(object);
+ return KERN_SUCCESS;
+ }
+#if VM_OBJECT_CACHE
+ if ((object->ref_count == 0) && (!object->terminating)) {
+ if (!vm_object_cache_lock_try()) {
+ vm_object_unlock(object);
+ goto restart;
+ }
+ queue_remove(&vm_object_cached_list, object,
+ vm_object_t, cached_list);
+ vm_object_cached_count--;
+ XPR(XPR_VM_OBJECT_CACHE,
+ "memory_object_recover_named: removing %X, head (%X, %X)\n",
+ object,
+ vm_object_cached_list.next,
+ vm_object_cached_list.prev, 0,0);
+
+ vm_object_cache_unlock();
+ }
+#endif
+ object->named = TRUE;
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count++;
+ vm_object_res_reference(object);
+ while (!object->pager_ready) {
+ vm_object_sleep(object,
+ VM_OBJECT_EVENT_PAGER_READY,
+ THREAD_UNINT);
+ }
+ vm_object_unlock(object);
+ return (KERN_SUCCESS);
+}
+
+
+/*
+ * vm_object_release_name:
+ *
+ * Enforces name semantic on memory_object reference count decrement
+ * This routine should not be called unless the caller holds a name
+ * reference gained through the memory_object_create_named.
+ *
+ * If the TERMINATE_IDLE flag is set, the call will return if the
+ * reference count is not 1. i.e. idle with the only remaining reference
+ * being the name.
+ * If the decision is made to proceed the name field flag is set to
+ * false and the reference count is decremented. If the RESPECT_CACHE
+ * flag is set and the reference count has gone to zero, the
+ * memory_object is checked to see if it is cacheable otherwise when
+ * the reference count is zero, it is simply terminated.
+ */
+
+__private_extern__ kern_return_t
+vm_object_release_name(
+ vm_object_t object,
+ int flags)
+{
+ vm_object_t shadow;
+ boolean_t original_object = TRUE;
+
+ while (object != VM_OBJECT_NULL) {
+
+ vm_object_lock(object);
+
+ assert(object->alive);
+ if (original_object)
+ assert(object->named);
+ assert(object->ref_count > 0);
+
+ /*
+ * We have to wait for initialization before
+ * destroying or caching the object.
+ */
+
+ if (object->pager_created && !object->pager_initialized) {
+ assert(!object->can_persist);
+ vm_object_assert_wait(object,
+ VM_OBJECT_EVENT_INITIALIZED,
+ THREAD_UNINT);
+ vm_object_unlock(object);
+ thread_block(THREAD_CONTINUE_NULL);
+ continue;
+ }
+
+ if (((object->ref_count > 1)
+ && (flags & MEMORY_OBJECT_TERMINATE_IDLE))
+ || (object->terminating)) {
+ vm_object_unlock(object);
+ return KERN_FAILURE;
+ } else {
+ if (flags & MEMORY_OBJECT_RELEASE_NO_OP) {
+ vm_object_unlock(object);
+ return KERN_SUCCESS;
+ }
+ }
+
+ if ((flags & MEMORY_OBJECT_RESPECT_CACHE) &&
+ (object->ref_count == 1)) {
+ if (original_object)
+ object->named = FALSE;
+ vm_object_unlock(object);
+ /* let vm_object_deallocate push this thing into */
+ /* the cache, if that it is where it is bound */
+ vm_object_deallocate(object);
+ return KERN_SUCCESS;
+ }
+ VM_OBJ_RES_DECR(object);
+ shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
+
+ if (object->ref_count == 1) {
+ if (vm_object_terminate(object) != KERN_SUCCESS) {
+ if (original_object) {
+ return KERN_FAILURE;
+ } else {
+ return KERN_SUCCESS;
+ }
+ }
+ if (shadow != VM_OBJECT_NULL) {
+ original_object = FALSE;
+ object = shadow;
+ continue;
+ }
+ return KERN_SUCCESS;
+ } else {
+ vm_object_lock_assert_exclusive(object);
+ object->ref_count--;
+ assert(object->ref_count > 0);
+ if(original_object)
+ object->named = FALSE;
+ vm_object_unlock(object);
+ return KERN_SUCCESS;
+ }
+ }
+ /*NOTREACHED*/
+ assert(0);
+ return KERN_FAILURE;
+}
+
+
+__private_extern__ kern_return_t
+vm_object_lock_request(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ memory_object_return_t should_return,
+ int flags,
+ vm_prot_t prot)
+{
+ __unused boolean_t should_flush;
+
+ should_flush = flags & MEMORY_OBJECT_DATA_FLUSH;
+
+ XPR(XPR_MEMORY_OBJECT,
+ "vm_o_lock_request, obj 0x%X off 0x%X size 0x%X flags %X prot %X\n",
+ object, offset, size,
+ (((should_return&1)<<1)|should_flush), prot);
+
+ /*
+ * Check for bogus arguments.
+ */
+ if (object == VM_OBJECT_NULL)
+ return (KERN_INVALID_ARGUMENT);
+
+ if ((prot & ~VM_PROT_ALL) != 0 && prot != VM_PROT_NO_CHANGE)
+ return (KERN_INVALID_ARGUMENT);
+
+ size = round_page_64(size);
+
+ /*
+ * Lock the object, and acquire a paging reference to
+ * prevent the memory_object reference from being released.
+ */
+ vm_object_lock(object);
+ vm_object_paging_begin(object);
+
+ (void)vm_object_update(object,
+ offset, size, NULL, NULL, should_return, flags, prot);
+
+ vm_object_paging_end(object);
+ vm_object_unlock(object);
+
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Empty a purgeable object by grabbing the physical pages assigned to it and
+ * putting them on the free queue without writing them to backing store, etc.
+ * When the pages are next touched they will be demand zero-fill pages. We
+ * skip pages which are busy, being paged in/out, wired, etc. We do _not_
+ * skip referenced/dirty pages, pages on the active queue, etc. We're more
* than happy to grab these since this is a purgeable object. We mark the
* object as "empty" after reaping its pages.
*
- * On entry the object must be locked and it must be
- * purgeable with no delayed copies pending.
+ * On entry the object must be locked and it must be
+ * purgeable with no delayed copies pending.
+ */
+void
+vm_object_purge(vm_object_t object, int flags)
+{
+ unsigned int object_page_count = 0;
+ unsigned int pgcount = 0;
+ boolean_t skipped_object = FALSE;
+
+ vm_object_lock_assert_exclusive(object);
+
+ if (object->purgable == VM_PURGABLE_DENY)
+ return;
+
+ assert(object->copy == VM_OBJECT_NULL);
+ assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE);
+
+ /*
+ * We need to set the object's state to VM_PURGABLE_EMPTY *before*
+ * reaping its pages. We update vm_page_purgeable_count in bulk
+ * and we don't want vm_page_remove() to update it again for each
+ * page we reap later.
+ *
+ * For the purgeable ledgers, pages from VOLATILE and EMPTY objects
+ * are all accounted for in the "volatile" ledgers, so this does not
+ * make any difference.
+ * If we transitioned directly from NONVOLATILE to EMPTY,
+ * vm_page_purgeable_count must have been updated when the object
+ * was dequeued from its volatile queue and the purgeable ledgers
+ * must have also been updated accordingly at that time (in
+ * vm_object_purgable_control()).
+ */
+ if (object->purgable == VM_PURGABLE_VOLATILE) {
+ unsigned int delta;
+ assert(object->resident_page_count >=
+ object->wired_page_count);
+ delta = (object->resident_page_count -
+ object->wired_page_count);
+ if (delta != 0) {
+ assert(vm_page_purgeable_count >=
+ delta);
+ OSAddAtomic(-delta,
+ (SInt32 *)&vm_page_purgeable_count);
+ }
+ if (object->wired_page_count != 0) {
+ assert(vm_page_purgeable_wired_count >=
+ object->wired_page_count);
+ OSAddAtomic(-object->wired_page_count,
+ (SInt32 *)&vm_page_purgeable_wired_count);
+ }
+ object->purgable = VM_PURGABLE_EMPTY;
+ }
+ assert(object->purgable == VM_PURGABLE_EMPTY);
+
+ object_page_count = object->resident_page_count;
+
+ vm_object_reap_pages(object, REAP_PURGEABLE);
+
+ if (object->pager != NULL) {
+
+ assert(VM_CONFIG_COMPRESSOR_IS_PRESENT);
+
+ if (object->activity_in_progress == 0 &&
+ object->paging_in_progress == 0) {
+ /*
+ * Also reap any memory coming from this object
+ * in the VM compressor.
+ *
+ * There are no operations in progress on the VM object
+ * and no operation can start while we're holding the
+ * VM object lock, so it's safe to reap the compressed
+ * pages and update the page counts.
+ */
+ pgcount = vm_compressor_pager_get_count(object->pager);
+ if (pgcount) {
+ pgcount = vm_compressor_pager_reap_pages(object->pager, flags);
+ vm_compressor_pager_count(object->pager,
+ -pgcount,
+ FALSE, /* shared */
+ object);
+ vm_purgeable_compressed_update(object,
+ -pgcount);
+ }
+ if ( !(flags & C_DONT_BLOCK)) {
+ assert(vm_compressor_pager_get_count(object->pager)
+ == 0);
+ }
+ } else {
+ /*
+ * There's some kind of paging activity in progress
+ * for this object, which could result in a page
+ * being compressed or decompressed, possibly while
+ * the VM object is not locked, so it could race
+ * with us.
+ *
+ * We can't really synchronize this without possibly
+ * causing a deadlock when the compressor needs to
+ * allocate or free memory while compressing or
+ * decompressing a page from a purgeable object
+ * mapped in the kernel_map...
+ *
+ * So let's not attempt to purge the compressor
+ * pager if there's any kind of operation in
+ * progress on the VM object.
+ */
+ skipped_object = TRUE;
+ }
+ }
+
+ vm_object_lock_assert_exclusive(object);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (MACHDBG_CODE(DBG_MACH_VM, OBJECT_PURGE_ONE)),
+ VM_KERNEL_UNSLIDE_OR_PERM(object), /* purged object */
+ object_page_count,
+ pgcount,
+ skipped_object,
+ 0);
+
+}
+
+
+/*
+ * vm_object_purgeable_control() allows the caller to control and investigate the
+ * state of a purgeable object. A purgeable object is created via a call to
+ * vm_allocate() with VM_FLAGS_PURGABLE specified. A purgeable object will
+ * never be coalesced with any other object -- even other purgeable objects --
+ * and will thus always remain a distinct object. A purgeable object has
+ * special semantics when its reference count is exactly 1. If its reference
+ * count is greater than 1, then a purgeable object will behave like a normal
+ * object and attempts to use this interface will result in an error return
+ * of KERN_INVALID_ARGUMENT.
+ *
+ * A purgeable object may be put into a "volatile" state which will make the
+ * object's pages elligable for being reclaimed without paging to backing
+ * store if the system runs low on memory. If the pages in a volatile
+ * purgeable object are reclaimed, the purgeable object is said to have been
+ * "emptied." When a purgeable object is emptied the system will reclaim as
+ * many pages from the object as it can in a convenient manner (pages already
+ * en route to backing store or busy for other reasons are left as is). When
+ * a purgeable object is made volatile, its pages will generally be reclaimed
+ * before other pages in the application's working set. This semantic is
+ * generally used by applications which can recreate the data in the object
+ * faster than it can be paged in. One such example might be media assets
+ * which can be reread from a much faster RAID volume.
+ *
+ * A purgeable object may be designated as "non-volatile" which means it will
+ * behave like all other objects in the system with pages being written to and
+ * read from backing store as needed to satisfy system memory needs. If the
+ * object was emptied before the object was made non-volatile, that fact will
+ * be returned as the old state of the purgeable object (see
+ * VM_PURGABLE_SET_STATE below). In this case, any pages of the object which
+ * were reclaimed as part of emptying the object will be refaulted in as
+ * zero-fill on demand. It is up to the application to note that an object
+ * was emptied and recreate the objects contents if necessary. When a
+ * purgeable object is made non-volatile, its pages will generally not be paged
+ * out to backing store in the immediate future. A purgeable object may also
+ * be manually emptied.
+ *
+ * Finally, the current state (non-volatile, volatile, volatile & empty) of a
+ * volatile purgeable object may be queried at any time. This information may
+ * be used as a control input to let the application know when the system is
+ * experiencing memory pressure and is reclaiming memory.
+ *
+ * The specified address may be any address within the purgeable object. If
+ * the specified address does not represent any object in the target task's
+ * virtual address space, then KERN_INVALID_ADDRESS will be returned. If the
+ * object containing the specified address is not a purgeable object, then
+ * KERN_INVALID_ARGUMENT will be returned. Otherwise, KERN_SUCCESS will be
+ * returned.
+ *
+ * The control parameter may be any one of VM_PURGABLE_SET_STATE or
+ * VM_PURGABLE_GET_STATE. For VM_PURGABLE_SET_STATE, the in/out parameter
+ * state is used to set the new state of the purgeable object and return its
+ * old state. For VM_PURGABLE_GET_STATE, the current state of the purgeable
+ * object is returned in the parameter state.
+ *
+ * The in/out parameter state may be one of VM_PURGABLE_NONVOLATILE,
+ * VM_PURGABLE_VOLATILE or VM_PURGABLE_EMPTY. These, respectively, represent
+ * the non-volatile, volatile and volatile/empty states described above.
+ * Setting the state of a purgeable object to VM_PURGABLE_EMPTY will
+ * immediately reclaim as many pages in the object as can be conveniently
+ * collected (some may have already been written to backing store or be
+ * otherwise busy).
+ *
+ * The process of making a purgeable object non-volatile and determining its
+ * previous state is atomic. Thus, if a purgeable object is made
+ * VM_PURGABLE_NONVOLATILE and the old state is returned as
+ * VM_PURGABLE_VOLATILE, then the purgeable object's previous contents are
+ * completely intact and will remain so until the object is made volatile
+ * again. If the old state is returned as VM_PURGABLE_EMPTY then the object
+ * was reclaimed while it was in a volatile state and its previous contents
+ * have been lost.
+ */
+/*
+ * The object must be locked.
+ */
+kern_return_t
+vm_object_purgable_control(
+ vm_object_t object,
+ vm_purgable_t control,
+ int *state)
+{
+ int old_state;
+ int new_state;
+
+ if (object == VM_OBJECT_NULL) {
+ /*
+ * Object must already be present or it can't be purgeable.
+ */
+ return KERN_INVALID_ARGUMENT;
+ }
+
+ vm_object_lock_assert_exclusive(object);
+
+ /*
+ * Get current state of the purgeable object.
+ */
+ old_state = object->purgable;
+ if (old_state == VM_PURGABLE_DENY)
+ return KERN_INVALID_ARGUMENT;
+
+ /* purgeable cant have delayed copies - now or in the future */
+ assert(object->copy == VM_OBJECT_NULL);
+ assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE);
+
+ /*
+ * Execute the desired operation.
+ */
+ if (control == VM_PURGABLE_GET_STATE) {
+ *state = old_state;
+ return KERN_SUCCESS;
+ }
+
+ if ((*state) & VM_PURGABLE_DEBUG_EMPTY) {
+ object->volatile_empty = TRUE;
+ }
+ if ((*state) & VM_PURGABLE_DEBUG_FAULT) {
+ object->volatile_fault = TRUE;
+ }
+
+ new_state = *state & VM_PURGABLE_STATE_MASK;
+ if (new_state == VM_PURGABLE_VOLATILE &&
+ object->volatile_empty) {
+ new_state = VM_PURGABLE_EMPTY;
+ }
+
+ switch (new_state) {
+ case VM_PURGABLE_DENY:
+ case VM_PURGABLE_NONVOLATILE:
+ object->purgable = new_state;
+
+ if (old_state == VM_PURGABLE_VOLATILE) {
+ unsigned int delta;
+
+ assert(object->resident_page_count >=
+ object->wired_page_count);
+ delta = (object->resident_page_count -
+ object->wired_page_count);
+
+ assert(vm_page_purgeable_count >= delta);
+
+ if (delta != 0) {
+ OSAddAtomic(-delta,
+ (SInt32 *)&vm_page_purgeable_count);
+ }
+ if (object->wired_page_count != 0) {
+ assert(vm_page_purgeable_wired_count >=
+ object->wired_page_count);
+ OSAddAtomic(-object->wired_page_count,
+ (SInt32 *)&vm_page_purgeable_wired_count);
+ }
+
+ vm_page_lock_queues();
+
+ /* object should be on a queue */
+ assert(object->objq.next != NULL &&
+ object->objq.prev != NULL);
+ purgeable_q_t queue;
+
+ /*
+ * Move object from its volatile queue to the
+ * non-volatile queue...
+ */
+ queue = vm_purgeable_object_remove(object);
+ assert(queue);
+
+ if (object->purgeable_when_ripe) {
+ vm_purgeable_token_delete_last(queue);
+ }
+ assert(queue->debug_count_objects>=0);
+
+ vm_page_unlock_queues();
+ }
+ if (old_state == VM_PURGABLE_VOLATILE ||
+ old_state == VM_PURGABLE_EMPTY) {
+ /*
+ * Transfer the object's pages from the volatile to
+ * non-volatile ledgers.
+ */
+ vm_purgeable_accounting(object, VM_PURGABLE_VOLATILE,
+ FALSE);
+ }
+
+ break;
+
+ case VM_PURGABLE_VOLATILE:
+ if (object->volatile_fault) {
+ vm_page_t p;
+ int refmod;
+
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+ if (p->busy ||
+ VM_PAGE_WIRED(p) ||
+ p->fictitious) {
+ continue;
+ }
+ refmod = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+ if ((refmod & VM_MEM_MODIFIED) &&
+ !p->dirty) {
+ SET_PAGE_DIRTY(p, FALSE);
+ }
+ }
+ }
+
+ if (old_state == VM_PURGABLE_EMPTY &&
+ object->resident_page_count == 0 &&
+ object->pager == NULL)
+ break;
+
+ purgeable_q_t queue;
+
+ /* find the correct queue */
+ if ((*state&VM_PURGABLE_ORDERING_MASK) == VM_PURGABLE_ORDERING_OBSOLETE)
+ queue = &purgeable_queues[PURGEABLE_Q_TYPE_OBSOLETE];
+ else {
+ if ((*state&VM_PURGABLE_BEHAVIOR_MASK) == VM_PURGABLE_BEHAVIOR_FIFO)
+ queue = &purgeable_queues[PURGEABLE_Q_TYPE_FIFO];
+ else
+ queue = &purgeable_queues[PURGEABLE_Q_TYPE_LIFO];
+ }
+
+ if (old_state == VM_PURGABLE_NONVOLATILE ||
+ old_state == VM_PURGABLE_EMPTY) {
+ unsigned int delta;
+
+ if ((*state & VM_PURGABLE_NO_AGING_MASK) ==
+ VM_PURGABLE_NO_AGING) {
+ object->purgeable_when_ripe = FALSE;
+ } else {
+ object->purgeable_when_ripe = TRUE;
+ }
+
+ if (object->purgeable_when_ripe) {
+ kern_return_t result;
+
+ /* try to add token... this can fail */
+ vm_page_lock_queues();
+
+ result = vm_purgeable_token_add(queue);
+ if (result != KERN_SUCCESS) {
+ vm_page_unlock_queues();
+ return result;
+ }
+ vm_page_unlock_queues();
+ }
+
+ assert(object->resident_page_count >=
+ object->wired_page_count);
+ delta = (object->resident_page_count -
+ object->wired_page_count);
+
+ if (delta != 0) {
+ OSAddAtomic(delta,
+ &vm_page_purgeable_count);
+ }
+ if (object->wired_page_count != 0) {
+ OSAddAtomic(object->wired_page_count,
+ &vm_page_purgeable_wired_count);
+ }
+
+ object->purgable = new_state;
+
+ /* object should be on "non-volatile" queue */
+ assert(object->objq.next != NULL);
+ assert(object->objq.prev != NULL);
+ }
+ else if (old_state == VM_PURGABLE_VOLATILE) {
+ purgeable_q_t old_queue;
+ boolean_t purgeable_when_ripe;
+
+ /*
+ * if reassigning priorities / purgeable groups, we don't change the
+ * token queue. So moving priorities will not make pages stay around longer.
+ * Reasoning is that the algorithm gives most priority to the most important
+ * object. If a new token is added, the most important object' priority is boosted.
+ * This biases the system already for purgeable queues that move a lot.
+ * It doesn't seem more biasing is neccessary in this case, where no new object is added.
+ */
+ assert(object->objq.next != NULL && object->objq.prev != NULL); /* object should be on a queue */
+
+ old_queue = vm_purgeable_object_remove(object);
+ assert(old_queue);
+
+ if ((*state & VM_PURGABLE_NO_AGING_MASK) ==
+ VM_PURGABLE_NO_AGING) {
+ purgeable_when_ripe = FALSE;
+ } else {
+ purgeable_when_ripe = TRUE;
+ }
+
+ if (old_queue != queue ||
+ (purgeable_when_ripe !=
+ object->purgeable_when_ripe)) {
+ kern_return_t result;
+
+ /* Changing queue. Have to move token. */
+ vm_page_lock_queues();
+ if (object->purgeable_when_ripe) {
+ vm_purgeable_token_delete_last(old_queue);
+ }
+ object->purgeable_when_ripe = purgeable_when_ripe;
+ if (object->purgeable_when_ripe) {
+ result = vm_purgeable_token_add(queue);
+ assert(result==KERN_SUCCESS); /* this should never fail since we just freed a token */
+ }
+ vm_page_unlock_queues();
+
+ }
+ };
+ vm_purgeable_object_add(object, queue, (*state&VM_VOLATILE_GROUP_MASK)>>VM_VOLATILE_GROUP_SHIFT );
+ if (old_state == VM_PURGABLE_NONVOLATILE) {
+ vm_purgeable_accounting(object, VM_PURGABLE_NONVOLATILE,
+ FALSE);
+ }
+
+ assert(queue->debug_count_objects>=0);
+
+ break;
+
+
+ case VM_PURGABLE_EMPTY:
+ if (object->volatile_fault) {
+ vm_page_t p;
+ int refmod;
+
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+ if (p->busy ||
+ VM_PAGE_WIRED(p) ||
+ p->fictitious) {
+ continue;
+ }
+ refmod = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+ if ((refmod & VM_MEM_MODIFIED) &&
+ !p->dirty) {
+ SET_PAGE_DIRTY(p, FALSE);
+ }
+ }
+ }
+
+ if (old_state == new_state) {
+ /* nothing changes */
+ break;
+ }
+
+ assert(old_state == VM_PURGABLE_NONVOLATILE ||
+ old_state == VM_PURGABLE_VOLATILE);
+ if (old_state == VM_PURGABLE_VOLATILE) {
+ purgeable_q_t old_queue;
+
+ /* object should be on a queue */
+ assert(object->objq.next != NULL &&
+ object->objq.prev != NULL);
+
+ old_queue = vm_purgeable_object_remove(object);
+ assert(old_queue);
+ if (object->purgeable_when_ripe) {
+ vm_page_lock_queues();
+ vm_purgeable_token_delete_first(old_queue);
+ vm_page_unlock_queues();
+ }
+ }
+
+ if (old_state == VM_PURGABLE_NONVOLATILE) {
+ /*
+ * This object's pages were previously accounted as
+ * "non-volatile" and now need to be accounted as
+ * "volatile".
+ */
+ vm_purgeable_accounting(object, VM_PURGABLE_NONVOLATILE,
+ FALSE);
+ /*
+ * Set to VM_PURGABLE_EMPTY because the pages are no
+ * longer accounted in the "non-volatile" ledger
+ * and are also not accounted for in
+ * "vm_page_purgeable_count".
+ */
+ object->purgable = VM_PURGABLE_EMPTY;
+ }
+
+ (void) vm_object_purge(object, 0);
+ assert(object->purgable == VM_PURGABLE_EMPTY);
+
+ break;
+ }
+
+ *state = old_state;
+
+ vm_object_lock_assert_exclusive(object);
+
+ return KERN_SUCCESS;
+}
+
+kern_return_t
+vm_object_get_page_counts(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ vm_object_size_t size,
+ unsigned int *resident_page_count,
+ unsigned int *dirty_page_count)
+{
+
+ kern_return_t kr = KERN_SUCCESS;
+ boolean_t count_dirty_pages = FALSE;
+ vm_page_t p = VM_PAGE_NULL;
+ unsigned int local_resident_count = 0;
+ unsigned int local_dirty_count = 0;
+ vm_object_offset_t cur_offset = 0;
+ vm_object_offset_t end_offset = 0;
+
+ if (object == VM_OBJECT_NULL)
+ return KERN_INVALID_ARGUMENT;
+
+
+ cur_offset = offset;
+
+ end_offset = offset + size;
+
+ vm_object_lock_assert_exclusive(object);
+
+ if (dirty_page_count != NULL) {
+
+ count_dirty_pages = TRUE;
+ }
+
+ if (resident_page_count != NULL && count_dirty_pages == FALSE) {
+ /*
+ * Fast path when:
+ * - we only want the resident page count, and,
+ * - the entire object is exactly covered by the request.
+ */
+ if (offset == 0 && (object->vo_size == size)) {
+
+ *resident_page_count = object->resident_page_count;
+ goto out;
+ }
+ }
+
+ if (object->resident_page_count <= (size >> PAGE_SHIFT)) {
+
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+
+ if (p->offset >= cur_offset && p->offset < end_offset) {
+
+ local_resident_count++;
+
+ if (count_dirty_pages) {
+
+ if (p->dirty || (p->wpmapped && pmap_is_modified(VM_PAGE_GET_PHYS_PAGE(p)))) {
+
+ local_dirty_count++;
+ }
+ }
+ }
+ }
+ } else {
+
+ for (cur_offset = offset; cur_offset < end_offset; cur_offset += PAGE_SIZE_64) {
+
+ p = vm_page_lookup(object, cur_offset);
+
+ if (p != VM_PAGE_NULL) {
+
+ local_resident_count++;
+
+ if (count_dirty_pages) {
+
+ if (p->dirty || (p->wpmapped && pmap_is_modified(VM_PAGE_GET_PHYS_PAGE(p)))) {
+
+ local_dirty_count++;
+ }
+ }
+ }
+ }
+
+ }
+
+ if (resident_page_count != NULL) {
+ *resident_page_count = local_resident_count;
+ }
+
+ if (dirty_page_count != NULL) {
+ *dirty_page_count = local_dirty_count;
+ }
+
+out:
+ return kr;
+}
+
+
+#if TASK_SWAPPER
+/*
+ * vm_object_res_deallocate
+ *
+ * (recursively) decrement residence counts on vm objects and their shadows.
+ * Called from vm_object_deallocate and when swapping out an object.
+ *
+ * The object is locked, and remains locked throughout the function,
+ * even as we iterate down the shadow chain. Locks on intermediate objects
+ * will be dropped, but not the original object.
+ *
+ * NOTE: this function used to use recursion, rather than iteration.
+ */
+
+__private_extern__ void
+vm_object_res_deallocate(
+ vm_object_t object)
+{
+ vm_object_t orig_object = object;
+ /*
+ * Object is locked so it can be called directly
+ * from vm_object_deallocate. Original object is never
+ * unlocked.
+ */
+ assert(object->res_count > 0);
+ while (--object->res_count == 0) {
+ assert(object->ref_count >= object->res_count);
+ vm_object_deactivate_all_pages(object);
+ /* iterate on shadow, if present */
+ if (object->shadow != VM_OBJECT_NULL) {
+ vm_object_t tmp_object = object->shadow;
+ vm_object_lock(tmp_object);
+ if (object != orig_object)
+ vm_object_unlock(object);
+ object = tmp_object;
+ assert(object->res_count > 0);
+ } else
+ break;
+ }
+ if (object != orig_object)
+ vm_object_unlock(object);
+}
+
+/*
+ * vm_object_res_reference
+ *
+ * Internal function to increment residence count on a vm object
+ * and its shadows. It is called only from vm_object_reference, and
+ * when swapping in a vm object, via vm_map_swap.
+ *
+ * The object is locked, and remains locked throughout the function,
+ * even as we iterate down the shadow chain. Locks on intermediate objects
+ * will be dropped, but not the original object.
+ *
+ * NOTE: this function used to use recursion, rather than iteration.
+ */
+
+__private_extern__ void
+vm_object_res_reference(
+ vm_object_t object)
+{
+ vm_object_t orig_object = object;
+ /*
+ * Object is locked, so this can be called directly
+ * from vm_object_reference. This lock is never released.
+ */
+ while ((++object->res_count == 1) &&
+ (object->shadow != VM_OBJECT_NULL)) {
+ vm_object_t tmp_object = object->shadow;
+
+ assert(object->ref_count >= object->res_count);
+ vm_object_lock(tmp_object);
+ if (object != orig_object)
+ vm_object_unlock(object);
+ object = tmp_object;
+ }
+ if (object != orig_object)
+ vm_object_unlock(object);
+ assert(orig_object->ref_count >= orig_object->res_count);
+}
+#endif /* TASK_SWAPPER */
+
+/*
+ * vm_object_reference:
+ *
+ * Gets another reference to the given object.
+ */
+#ifdef vm_object_reference
+#undef vm_object_reference
+#endif
+__private_extern__ void
+vm_object_reference(
+ vm_object_t object)
+{
+ if (object == VM_OBJECT_NULL)
+ return;
+
+ vm_object_lock(object);
+ assert(object->ref_count > 0);
+ vm_object_reference_locked(object);
+ vm_object_unlock(object);
+}
+
+#ifdef MACH_BSD
+/*
+ * Scale the vm_object_cache
+ * This is required to make sure that the vm_object_cache is big
+ * enough to effectively cache the mapped file.
+ * This is really important with UBC as all the regular file vnodes
+ * have memory object associated with them. Havving this cache too
+ * small results in rapid reclaim of vnodes and hurts performance a LOT!
+ *
+ * This is also needed as number of vnodes can be dynamically scaled.
+ */
+kern_return_t
+adjust_vm_object_cache(
+ __unused vm_size_t oval,
+ __unused vm_size_t nval)
+{
+#if VM_OBJECT_CACHE
+ vm_object_cached_max = nval;
+ vm_object_cache_trim(FALSE);
+#endif
+ return (KERN_SUCCESS);
+}
+#endif /* MACH_BSD */
+
+
+/*
+ * vm_object_transpose
+ *
+ * This routine takes two VM objects of the same size and exchanges
+ * their backing store.
+ * The objects should be "quiesced" via a UPL operation with UPL_SET_IO_WIRE
+ * and UPL_BLOCK_ACCESS if they are referenced anywhere.
+ *
+ * The VM objects must not be locked by caller.
*/
-void
-vm_object_purge(vm_object_t object)
+unsigned int vm_object_transpose_count = 0;
+kern_return_t
+vm_object_transpose(
+ vm_object_t object1,
+ vm_object_t object2,
+ vm_object_size_t transpose_size)
{
- vm_object_lock_assert_exclusive(object);
+ vm_object_t tmp_object;
+ kern_return_t retval;
+ boolean_t object1_locked, object2_locked;
+ vm_page_t page;
+ vm_object_offset_t page_offset;
+ lck_mtx_t *hash_lck;
+ vm_object_hash_entry_t hash_entry;
+
+ tmp_object = VM_OBJECT_NULL;
+ object1_locked = FALSE; object2_locked = FALSE;
+
+ if (object1 == object2 ||
+ object1 == VM_OBJECT_NULL ||
+ object2 == VM_OBJECT_NULL) {
+ /*
+ * If the 2 VM objects are the same, there's
+ * no point in exchanging their backing store.
+ */
+ retval = KERN_INVALID_VALUE;
+ goto done;
+ }
+
+ /*
+ * Since we need to lock both objects at the same time,
+ * make sure we always lock them in the same order to
+ * avoid deadlocks.
+ */
+ if (object1 > object2) {
+ tmp_object = object1;
+ object1 = object2;
+ object2 = tmp_object;
+ }
+
+ /*
+ * Allocate a temporary VM object to hold object1's contents
+ * while we copy object2 to object1.
+ */
+ tmp_object = vm_object_allocate(transpose_size);
+ vm_object_lock(tmp_object);
+ tmp_object->can_persist = FALSE;
+
+
+ /*
+ * Grab control of the 1st VM object.
+ */
+ vm_object_lock(object1);
+ object1_locked = TRUE;
+ if (!object1->alive || object1->terminating ||
+ object1->copy || object1->shadow || object1->shadowed ||
+ object1->purgable != VM_PURGABLE_DENY) {
+ /*
+ * We don't deal with copy or shadow objects (yet).
+ */
+ retval = KERN_INVALID_VALUE;
+ goto done;
+ }
+ /*
+ * We're about to mess with the object's backing store and
+ * taking a "paging_in_progress" reference wouldn't be enough
+ * to prevent any paging activity on this object, so the caller should
+ * have "quiesced" the objects beforehand, via a UPL operation with
+ * UPL_SET_IO_WIRE (to make sure all the pages are there and wired)
+ * and UPL_BLOCK_ACCESS (to mark the pages "busy").
+ *
+ * Wait for any paging operation to complete (but only paging, not
+ * other kind of activities not linked to the pager). After we're
+ * statisfied that there's no more paging in progress, we keep the
+ * object locked, to guarantee that no one tries to access its pager.
+ */
+ vm_object_paging_only_wait(object1, THREAD_UNINT);
+
+ /*
+ * Same as above for the 2nd object...
+ */
+ vm_object_lock(object2);
+ object2_locked = TRUE;
+ if (! object2->alive || object2->terminating ||
+ object2->copy || object2->shadow || object2->shadowed ||
+ object2->purgable != VM_PURGABLE_DENY) {
+ retval = KERN_INVALID_VALUE;
+ goto done;
+ }
+ vm_object_paging_only_wait(object2, THREAD_UNINT);
+
+
+ if (object1->vo_size != object2->vo_size ||
+ object1->vo_size != transpose_size) {
+ /*
+ * If the 2 objects don't have the same size, we can't
+ * exchange their backing stores or one would overflow.
+ * If their size doesn't match the caller's
+ * "transpose_size", we can't do it either because the
+ * transpose operation will affect the entire span of
+ * the objects.
+ */
+ retval = KERN_INVALID_VALUE;
+ goto done;
+ }
+
+
+ /*
+ * Transpose the lists of resident pages.
+ * This also updates the resident_page_count and the memq_hint.
+ */
+ if (object1->phys_contiguous || vm_page_queue_empty(&object1->memq)) {
+ /*
+ * No pages in object1, just transfer pages
+ * from object2 to object1. No need to go through
+ * an intermediate object.
+ */
+ while (!vm_page_queue_empty(&object2->memq)) {
+ page = (vm_page_t) vm_page_queue_first(&object2->memq);
+ vm_page_rename(page, object1, page->offset, FALSE);
+ }
+ assert(vm_page_queue_empty(&object2->memq));
+ } else if (object2->phys_contiguous || vm_page_queue_empty(&object2->memq)) {
+ /*
+ * No pages in object2, just transfer pages
+ * from object1 to object2. No need to go through
+ * an intermediate object.
+ */
+ while (!vm_page_queue_empty(&object1->memq)) {
+ page = (vm_page_t) vm_page_queue_first(&object1->memq);
+ vm_page_rename(page, object2, page->offset, FALSE);
+ }
+ assert(vm_page_queue_empty(&object1->memq));
+ } else {
+ /* transfer object1's pages to tmp_object */
+ while (!vm_page_queue_empty(&object1->memq)) {
+ page = (vm_page_t) vm_page_queue_first(&object1->memq);
+ page_offset = page->offset;
+ vm_page_remove(page, TRUE);
+ page->offset = page_offset;
+ vm_page_queue_enter(&tmp_object->memq, page, vm_page_t, listq);
+ }
+ assert(vm_page_queue_empty(&object1->memq));
+ /* transfer object2's pages to object1 */
+ while (!vm_page_queue_empty(&object2->memq)) {
+ page = (vm_page_t) vm_page_queue_first(&object2->memq);
+ vm_page_rename(page, object1, page->offset, FALSE);
+ }
+ assert(vm_page_queue_empty(&object2->memq));
+ /* transfer tmp_object's pages to object2 */
+ while (!vm_page_queue_empty(&tmp_object->memq)) {
+ page = (vm_page_t) vm_page_queue_first(&tmp_object->memq);
+ vm_page_queue_remove(&tmp_object->memq, page,
+ vm_page_t, listq);
+ vm_page_insert(page, object2, page->offset);
+ }
+ assert(vm_page_queue_empty(&tmp_object->memq));
+ }
+
+#define __TRANSPOSE_FIELD(field) \
+MACRO_BEGIN \
+ tmp_object->field = object1->field; \
+ object1->field = object2->field; \
+ object2->field = tmp_object->field; \
+MACRO_END
+
+ /* "Lock" refers to the object not its contents */
+ /* "size" should be identical */
+ assert(object1->vo_size == object2->vo_size);
+ /* "memq_hint" was updated above when transposing pages */
+ /* "ref_count" refers to the object not its contents */
+#if TASK_SWAPPER
+ /* "res_count" refers to the object not its contents */
+#endif
+ /* "resident_page_count" was updated above when transposing pages */
+ /* "wired_page_count" was updated above when transposing pages */
+ /* "reusable_page_count" was updated above when transposing pages */
+ /* there should be no "copy" */
+ assert(!object1->copy);
+ assert(!object2->copy);
+ /* there should be no "shadow" */
+ assert(!object1->shadow);
+ assert(!object2->shadow);
+ __TRANSPOSE_FIELD(vo_shadow_offset); /* used by phys_contiguous objects */
+ __TRANSPOSE_FIELD(pager);
+ __TRANSPOSE_FIELD(paging_offset);
+ __TRANSPOSE_FIELD(pager_control);
+ /* update the memory_objects' pointers back to the VM objects */
+ if (object1->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
+ memory_object_control_collapse(object1->pager_control,
+ object1);
+ }
+ if (object2->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
+ memory_object_control_collapse(object2->pager_control,
+ object2);
+ }
+ __TRANSPOSE_FIELD(copy_strategy);
+ /* "paging_in_progress" refers to the object not its contents */
+ assert(!object1->paging_in_progress);
+ assert(!object2->paging_in_progress);
+ assert(object1->activity_in_progress);
+ assert(object2->activity_in_progress);
+ /* "all_wanted" refers to the object not its contents */
+ __TRANSPOSE_FIELD(pager_created);
+ __TRANSPOSE_FIELD(pager_initialized);
+ __TRANSPOSE_FIELD(pager_ready);
+ __TRANSPOSE_FIELD(pager_trusted);
+ __TRANSPOSE_FIELD(can_persist);
+ __TRANSPOSE_FIELD(internal);
+ __TRANSPOSE_FIELD(temporary);
+ __TRANSPOSE_FIELD(private);
+ __TRANSPOSE_FIELD(pageout);
+ /* "alive" should be set */
+ assert(object1->alive);
+ assert(object2->alive);
+ /* "purgeable" should be non-purgeable */
+ assert(object1->purgable == VM_PURGABLE_DENY);
+ assert(object2->purgable == VM_PURGABLE_DENY);
+ /* "shadowed" refers to the the object not its contents */
+ __TRANSPOSE_FIELD(purgeable_when_ripe);
+ __TRANSPOSE_FIELD(advisory_pageout);
+ __TRANSPOSE_FIELD(true_share);
+ /* "terminating" should not be set */
+ assert(!object1->terminating);
+ assert(!object2->terminating);
+ __TRANSPOSE_FIELD(named);
+ /* "shadow_severed" refers to the object not its contents */
+ __TRANSPOSE_FIELD(phys_contiguous);
+ __TRANSPOSE_FIELD(nophyscache);
+ /* "cached_list.next" points to transposed object */
+ object1->cached_list.next = (queue_entry_t) object2;
+ object2->cached_list.next = (queue_entry_t) object1;
+ /* "cached_list.prev" should be NULL */
+ assert(object1->cached_list.prev == NULL);
+ assert(object2->cached_list.prev == NULL);
+ /* "msr_q" is linked to the object not its contents */
+ assert(queue_empty(&object1->msr_q));
+ assert(queue_empty(&object2->msr_q));
+ __TRANSPOSE_FIELD(last_alloc);
+ __TRANSPOSE_FIELD(sequential);
+ __TRANSPOSE_FIELD(pages_created);
+ __TRANSPOSE_FIELD(pages_used);
+ __TRANSPOSE_FIELD(scan_collisions);
+ __TRANSPOSE_FIELD(cow_hint);
+#if MACH_ASSERT
+ __TRANSPOSE_FIELD(paging_object);
+#endif
+ __TRANSPOSE_FIELD(wimg_bits);
+ __TRANSPOSE_FIELD(set_cache_attr);
+ __TRANSPOSE_FIELD(code_signed);
+ if (object1->hashed) {
+ hash_lck = vm_object_hash_lock_spin(object2->pager);
+ hash_entry = vm_object_hash_lookup(object2->pager, FALSE);
+ assert(hash_entry != VM_OBJECT_HASH_ENTRY_NULL);
+ hash_entry->object = object2;
+ vm_object_hash_unlock(hash_lck);
+ }
+ if (object2->hashed) {
+ hash_lck = vm_object_hash_lock_spin(object1->pager);
+ hash_entry = vm_object_hash_lookup(object1->pager, FALSE);
+ assert(hash_entry != VM_OBJECT_HASH_ENTRY_NULL);
+ hash_entry->object = object1;
+ vm_object_hash_unlock(hash_lck);
+ }
+ __TRANSPOSE_FIELD(hashed);
+ object1->transposed = TRUE;
+ object2->transposed = TRUE;
+ __TRANSPOSE_FIELD(mapping_in_progress);
+ __TRANSPOSE_FIELD(volatile_empty);
+ __TRANSPOSE_FIELD(volatile_fault);
+ __TRANSPOSE_FIELD(all_reusable);
+ assert(object1->blocked_access);
+ assert(object2->blocked_access);
+ assert(object1->__object2_unused_bits == 0);
+ assert(object2->__object2_unused_bits == 0);
+#if UPL_DEBUG
+ /* "uplq" refers to the object not its contents (see upl_transpose()) */
+#endif
+ assert((object1->purgable == VM_PURGABLE_DENY) || (object1->objq.next == NULL));
+ assert((object1->purgable == VM_PURGABLE_DENY) || (object1->objq.prev == NULL));
+ assert((object2->purgable == VM_PURGABLE_DENY) || (object2->objq.next == NULL));
+ assert((object2->purgable == VM_PURGABLE_DENY) || (object2->objq.prev == NULL));
- if (object->purgable == VM_PURGABLE_DENY)
- return;
+#undef __TRANSPOSE_FIELD
- assert(object->copy == VM_OBJECT_NULL);
- assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE);
+ retval = KERN_SUCCESS;
- if(object->purgable == VM_PURGABLE_VOLATILE) {
- unsigned int delta;
- assert(object->resident_page_count >=
- object->wired_page_count);
- delta = (object->resident_page_count -
- object->wired_page_count);
- if (delta != 0) {
- assert(vm_page_purgeable_count >=
- delta);
- OSAddAtomic(-delta,
- (SInt32 *)&vm_page_purgeable_count);
- }
- if (object->wired_page_count != 0) {
- assert(vm_page_purgeable_wired_count >=
- object->wired_page_count);
- OSAddAtomic(-object->wired_page_count,
- (SInt32 *)&vm_page_purgeable_wired_count);
- }
+done:
+ /*
+ * Cleanup.
+ */
+ if (tmp_object != VM_OBJECT_NULL) {
+ vm_object_unlock(tmp_object);
+ /*
+ * Re-initialize the temporary object to avoid
+ * deallocating a real pager.
+ */
+ _vm_object_allocate(transpose_size, tmp_object);
+ vm_object_deallocate(tmp_object);
+ tmp_object = VM_OBJECT_NULL;
}
- object->purgable = VM_PURGABLE_EMPTY;
-
- vm_object_reap_pages(object, REAP_PURGEABLE);
+
+ if (object1_locked) {
+ vm_object_unlock(object1);
+ object1_locked = FALSE;
+ }
+ if (object2_locked) {
+ vm_object_unlock(object2);
+ object2_locked = FALSE;
+ }
+
+ vm_object_transpose_count++;
+
+ return retval;
}
-
+
/*
- * vm_object_purgeable_control() allows the caller to control and investigate the
- * state of a purgeable object. A purgeable object is created via a call to
- * vm_allocate() with VM_FLAGS_PURGABLE specified. A purgeable object will
- * never be coalesced with any other object -- even other purgeable objects --
- * and will thus always remain a distinct object. A purgeable object has
- * special semantics when its reference count is exactly 1. If its reference
- * count is greater than 1, then a purgeable object will behave like a normal
- * object and attempts to use this interface will result in an error return
- * of KERN_INVALID_ARGUMENT.
- *
- * A purgeable object may be put into a "volatile" state which will make the
- * object's pages elligable for being reclaimed without paging to backing
- * store if the system runs low on memory. If the pages in a volatile
- * purgeable object are reclaimed, the purgeable object is said to have been
- * "emptied." When a purgeable object is emptied the system will reclaim as
- * many pages from the object as it can in a convenient manner (pages already
- * en route to backing store or busy for other reasons are left as is). When
- * a purgeable object is made volatile, its pages will generally be reclaimed
- * before other pages in the application's working set. This semantic is
- * generally used by applications which can recreate the data in the object
- * faster than it can be paged in. One such example might be media assets
- * which can be reread from a much faster RAID volume.
- *
- * A purgeable object may be designated as "non-volatile" which means it will
- * behave like all other objects in the system with pages being written to and
- * read from backing store as needed to satisfy system memory needs. If the
- * object was emptied before the object was made non-volatile, that fact will
- * be returned as the old state of the purgeable object (see
- * VM_PURGABLE_SET_STATE below). In this case, any pages of the object which
- * were reclaimed as part of emptying the object will be refaulted in as
- * zero-fill on demand. It is up to the application to note that an object
- * was emptied and recreate the objects contents if necessary. When a
- * purgeable object is made non-volatile, its pages will generally not be paged
- * out to backing store in the immediate future. A purgeable object may also
- * be manually emptied.
- *
- * Finally, the current state (non-volatile, volatile, volatile & empty) of a
- * volatile purgeable object may be queried at any time. This information may
- * be used as a control input to let the application know when the system is
- * experiencing memory pressure and is reclaiming memory.
+ * vm_object_cluster_size
*
- * The specified address may be any address within the purgeable object. If
- * the specified address does not represent any object in the target task's
- * virtual address space, then KERN_INVALID_ADDRESS will be returned. If the
- * object containing the specified address is not a purgeable object, then
- * KERN_INVALID_ARGUMENT will be returned. Otherwise, KERN_SUCCESS will be
- * returned.
+ * Determine how big a cluster we should issue an I/O for...
*
- * The control parameter may be any one of VM_PURGABLE_SET_STATE or
- * VM_PURGABLE_GET_STATE. For VM_PURGABLE_SET_STATE, the in/out parameter
- * state is used to set the new state of the purgeable object and return its
- * old state. For VM_PURGABLE_GET_STATE, the current state of the purgeable
- * object is returned in the parameter state.
+ * Inputs: *start == offset of page needed
+ * *length == maximum cluster pager can handle
+ * Outputs: *start == beginning offset of cluster
+ * *length == length of cluster to try
*
- * The in/out parameter state may be one of VM_PURGABLE_NONVOLATILE,
- * VM_PURGABLE_VOLATILE or VM_PURGABLE_EMPTY. These, respectively, represent
- * the non-volatile, volatile and volatile/empty states described above.
- * Setting the state of a purgeable object to VM_PURGABLE_EMPTY will
- * immediately reclaim as many pages in the object as can be conveniently
- * collected (some may have already been written to backing store or be
- * otherwise busy).
+ * The original *start will be encompassed by the cluster
*
- * The process of making a purgeable object non-volatile and determining its
- * previous state is atomic. Thus, if a purgeable object is made
- * VM_PURGABLE_NONVOLATILE and the old state is returned as
- * VM_PURGABLE_VOLATILE, then the purgeable object's previous contents are
- * completely intact and will remain so until the object is made volatile
- * again. If the old state is returned as VM_PURGABLE_EMPTY then the object
- * was reclaimed while it was in a volatile state and its previous contents
- * have been lost.
*/
+extern int speculative_reads_disabled;
+extern int ignore_is_ssd;
+
/*
- * The object must be locked.
+ * Try to always keep these values an even multiple of PAGE_SIZE. We use these values
+ * to derive min_ph_bytes and max_ph_bytes (IMP: bytes not # of pages) and expect those values to
+ * always be page-aligned. The derivation could involve operations (e.g. division)
+ * that could give us non-page-size aligned values if we start out with values that
+ * are odd multiples of PAGE_SIZE.
*/
-kern_return_t
-vm_object_purgable_control(
- vm_object_t object,
- vm_purgable_t control,
- int *state)
+ unsigned int preheat_max_bytes = MAX_UPL_TRANSFER_BYTES;
+unsigned int preheat_min_bytes = (1024 * 32);
+
+
+__private_extern__ void
+vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
+ vm_size_t *length, vm_object_fault_info_t fault_info, uint32_t *io_streaming)
{
- int old_state;
- int new_state;
+ vm_size_t pre_heat_size;
+ vm_size_t tail_size;
+ vm_size_t head_size;
+ vm_size_t max_length;
+ vm_size_t cluster_size;
+ vm_object_offset_t object_size;
+ vm_object_offset_t orig_start;
+ vm_object_offset_t target_start;
+ vm_object_offset_t offset;
+ vm_behavior_t behavior;
+ boolean_t look_behind = TRUE;
+ boolean_t look_ahead = TRUE;
+ boolean_t isSSD = FALSE;
+ uint32_t throttle_limit;
+ int sequential_run;
+ int sequential_behavior = VM_BEHAVIOR_SEQUENTIAL;
+ vm_size_t max_ph_size;
+ vm_size_t min_ph_size;
- if (object == VM_OBJECT_NULL) {
- /*
- * Object must already be present or it can't be purgeable.
- */
- return KERN_INVALID_ARGUMENT;
- }
+ assert( !(*length & PAGE_MASK));
+ assert( !(*start & PAGE_MASK_64));
/*
- * Get current state of the purgeable object.
+ * remember maxiumum length of run requested
*/
- old_state = object->purgable;
- if (old_state == VM_PURGABLE_DENY)
- return KERN_INVALID_ARGUMENT;
-
- /* purgeable cant have delayed copies - now or in the future */
- assert(object->copy == VM_OBJECT_NULL);
- assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE);
-
+ max_length = *length;
/*
- * Execute the desired operation.
+ * we'll always return a cluster size of at least
+ * 1 page, since the original fault must always
+ * be processed
*/
- if (control == VM_PURGABLE_GET_STATE) {
- *state = old_state;
- return KERN_SUCCESS;
- }
-
- if ((*state) & VM_PURGABLE_DEBUG_EMPTY) {
- object->volatile_empty = TRUE;
- }
- if ((*state) & VM_PURGABLE_DEBUG_FAULT) {
- object->volatile_fault = TRUE;
- }
+ *length = PAGE_SIZE;
+ *io_streaming = 0;
- new_state = *state & VM_PURGABLE_STATE_MASK;
- if (new_state == VM_PURGABLE_VOLATILE &&
- object->volatile_empty) {
- new_state = VM_PURGABLE_EMPTY;
+ if (speculative_reads_disabled || fault_info == NULL) {
+ /*
+ * no cluster... just fault the page in
+ */
+ return;
}
+ orig_start = *start;
+ target_start = orig_start;
+ cluster_size = round_page(fault_info->cluster_size);
+ behavior = fault_info->behavior;
- switch (new_state) {
- case VM_PURGABLE_DENY:
- case VM_PURGABLE_NONVOLATILE:
- object->purgable = new_state;
-
- if (old_state == VM_PURGABLE_VOLATILE) {
- unsigned int delta;
-
- assert(object->resident_page_count >=
- object->wired_page_count);
- delta = (object->resident_page_count -
- object->wired_page_count);
-
- assert(vm_page_purgeable_count >= delta);
-
- if (delta != 0) {
- OSAddAtomic(-delta,
- (SInt32 *)&vm_page_purgeable_count);
- }
- if (object->wired_page_count != 0) {
- assert(vm_page_purgeable_wired_count >=
- object->wired_page_count);
- OSAddAtomic(-object->wired_page_count,
- (SInt32 *)&vm_page_purgeable_wired_count);
- }
-
- vm_page_lock_queues();
-
- assert(object->objq.next != NULL && object->objq.prev != NULL); /* object should be on a queue */
- purgeable_q_t queue = vm_purgeable_object_remove(object);
- assert(queue);
-
- vm_purgeable_token_delete_first(queue);
- assert(queue->debug_count_objects>=0);
-
- vm_page_unlock_queues();
- }
- break;
+ vm_object_lock(object);
- case VM_PURGABLE_VOLATILE:
- if (object->volatile_fault) {
- vm_page_t p;
- int refmod;
+ if (object->pager == MEMORY_OBJECT_NULL)
+ goto out; /* pager is gone for this object, nothing more to do */
- queue_iterate(&object->memq, p, vm_page_t, listq) {
- if (p->busy ||
- VM_PAGE_WIRED(p) ||
- p->fictitious) {
- continue;
- }
- refmod = pmap_disconnect(p->phys_page);
- if ((refmod & VM_MEM_MODIFIED) &&
- !p->dirty) {
- p->dirty = TRUE;
- }
- }
+ if (!ignore_is_ssd)
+ vnode_pager_get_isSSD(object->pager, &isSSD);
+
+ min_ph_size = round_page(preheat_min_bytes);
+ max_ph_size = round_page(preheat_max_bytes);
+
+ if (isSSD) {
+ min_ph_size /= 2;
+ max_ph_size /= 8;
+
+ if (min_ph_size & PAGE_MASK_64) {
+ min_ph_size = trunc_page(min_ph_size);
}
-
- if (old_state == VM_PURGABLE_EMPTY &&
- object->resident_page_count == 0)
- break;
- purgeable_q_t queue;
-
- /* find the correct queue */
- if ((*state&VM_PURGABLE_ORDERING_MASK) == VM_PURGABLE_ORDERING_OBSOLETE)
- queue = &purgeable_queues[PURGEABLE_Q_TYPE_OBSOLETE];
- else {
- if ((*state&VM_PURGABLE_BEHAVIOR_MASK) == VM_PURGABLE_BEHAVIOR_FIFO)
- queue = &purgeable_queues[PURGEABLE_Q_TYPE_FIFO];
- else
- queue = &purgeable_queues[PURGEABLE_Q_TYPE_LIFO];
+ if (max_ph_size & PAGE_MASK_64) {
+ max_ph_size = trunc_page(max_ph_size);
}
-
- if (old_state == VM_PURGABLE_NONVOLATILE ||
- old_state == VM_PURGABLE_EMPTY) {
- unsigned int delta;
+ }
- /* try to add token... this can fail */
- vm_page_lock_queues();
+ if (min_ph_size < PAGE_SIZE)
+ min_ph_size = PAGE_SIZE;
- kern_return_t result = vm_purgeable_token_add(queue);
- if (result != KERN_SUCCESS) {
- vm_page_unlock_queues();
- return result;
- }
- vm_page_unlock_queues();
+ if (max_ph_size < PAGE_SIZE)
+ max_ph_size = PAGE_SIZE;
+ else if (max_ph_size > MAX_UPL_TRANSFER_BYTES)
+ max_ph_size = MAX_UPL_TRANSFER_BYTES;
- assert(object->resident_page_count >=
- object->wired_page_count);
- delta = (object->resident_page_count -
- object->wired_page_count);
+ if (max_length > max_ph_size)
+ max_length = max_ph_size;
- if (delta != 0) {
- OSAddAtomic(delta,
- &vm_page_purgeable_count);
- }
- if (object->wired_page_count != 0) {
- OSAddAtomic(object->wired_page_count,
- &vm_page_purgeable_wired_count);
- }
+ if (max_length <= PAGE_SIZE)
+ goto out;
- object->purgable = new_state;
+ if (object->internal)
+ object_size = object->vo_size;
+ else
+ vnode_pager_get_object_size(object->pager, &object_size);
- /* object should not be on a queue */
- assert(object->objq.next == NULL && object->objq.prev == NULL);
- }
- else if (old_state == VM_PURGABLE_VOLATILE) {
- /*
- * if reassigning priorities / purgeable groups, we don't change the
- * token queue. So moving priorities will not make pages stay around longer.
- * Reasoning is that the algorithm gives most priority to the most important
- * object. If a new token is added, the most important object' priority is boosted.
- * This biases the system already for purgeable queues that move a lot.
- * It doesn't seem more biasing is neccessary in this case, where no new object is added.
- */
- assert(object->objq.next != NULL && object->objq.prev != NULL); /* object should be on a queue */
-
- purgeable_q_t old_queue=vm_purgeable_object_remove(object);
- assert(old_queue);
-
- if (old_queue != queue) {
- kern_return_t result;
+ object_size = round_page_64(object_size);
- /* Changing queue. Have to move token. */
- vm_page_lock_queues();
- vm_purgeable_token_delete_first(old_queue);
- result = vm_purgeable_token_add(queue);
- vm_page_unlock_queues();
+ if (orig_start >= object_size) {
+ /*
+ * fault occurred beyond the EOF...
+ * we need to punt w/o changing the
+ * starting offset
+ */
+ goto out;
+ }
+ if (object->pages_used > object->pages_created) {
+ /*
+ * must have wrapped our 32 bit counters
+ * so reset
+ */
+ object->pages_used = object->pages_created = 0;
+ }
+ if ((sequential_run = object->sequential)) {
+ if (sequential_run < 0) {
+ sequential_behavior = VM_BEHAVIOR_RSEQNTL;
+ sequential_run = 0 - sequential_run;
+ } else {
+ sequential_behavior = VM_BEHAVIOR_SEQUENTIAL;
+ }
- assert(result==KERN_SUCCESS); /* this should never fail since we just freed a token */
- }
- };
- vm_purgeable_object_add(object, queue, (*state&VM_VOLATILE_GROUP_MASK)>>VM_VOLATILE_GROUP_SHIFT );
+ }
+ switch (behavior) {
- assert(queue->debug_count_objects>=0);
-
- break;
+ default:
+ behavior = VM_BEHAVIOR_DEFAULT;
+ case VM_BEHAVIOR_DEFAULT:
+ if (object->internal && fault_info->user_tag == VM_MEMORY_STACK)
+ goto out;
- case VM_PURGABLE_EMPTY:
- if (object->volatile_fault) {
- vm_page_t p;
- int refmod;
+ if (sequential_run >= (3 * PAGE_SIZE)) {
+ pre_heat_size = sequential_run + PAGE_SIZE;
- queue_iterate(&object->memq, p, vm_page_t, listq) {
- if (p->busy ||
- VM_PAGE_WIRED(p) ||
- p->fictitious) {
- continue;
- }
- refmod = pmap_disconnect(p->phys_page);
- if ((refmod & VM_MEM_MODIFIED) &&
- !p->dirty) {
- p->dirty = TRUE;
- }
- }
- }
+ if (sequential_behavior == VM_BEHAVIOR_SEQUENTIAL)
+ look_behind = FALSE;
+ else
+ look_ahead = FALSE;
- if (old_state != new_state) {
- assert(old_state == VM_PURGABLE_NONVOLATILE ||
- old_state == VM_PURGABLE_VOLATILE);
- if (old_state == VM_PURGABLE_VOLATILE) {
- purgeable_q_t old_queue;
+ *io_streaming = 1;
+ } else {
- /* object should be on a queue */
- assert(object->objq.next != NULL &&
- object->objq.prev != NULL);
- old_queue = vm_purgeable_object_remove(object);
- assert(old_queue);
- vm_page_lock_queues();
- vm_purgeable_token_delete_first(old_queue);
- vm_page_unlock_queues();
+ if (object->pages_created < (20 * (min_ph_size >> PAGE_SHIFT))) {
+ /*
+ * prime the pump
+ */
+ pre_heat_size = min_ph_size;
+ } else {
+ /*
+ * Linear growth in PH size: The maximum size is max_length...
+ * this cacluation will result in a size that is neither a
+ * power of 2 nor a multiple of PAGE_SIZE... so round
+ * it up to the nearest PAGE_SIZE boundary
+ */
+ pre_heat_size = (max_length * (uint64_t)object->pages_used) / object->pages_created;
+
+ if (pre_heat_size < min_ph_size)
+ pre_heat_size = min_ph_size;
+ else
+ pre_heat_size = round_page(pre_heat_size);
}
- (void) vm_object_purge(object);
}
break;
+ case VM_BEHAVIOR_RANDOM:
+ if ((pre_heat_size = cluster_size) <= PAGE_SIZE)
+ goto out;
+ break;
+
+ case VM_BEHAVIOR_SEQUENTIAL:
+ if ((pre_heat_size = cluster_size) == 0)
+ pre_heat_size = sequential_run + PAGE_SIZE;
+ look_behind = FALSE;
+ *io_streaming = 1;
+
+ break;
+
+ case VM_BEHAVIOR_RSEQNTL:
+ if ((pre_heat_size = cluster_size) == 0)
+ pre_heat_size = sequential_run + PAGE_SIZE;
+ look_ahead = FALSE;
+ *io_streaming = 1;
+
+ break;
+
}
- *state = old_state;
+ throttle_limit = (uint32_t) max_length;
+ assert(throttle_limit == max_length);
- return KERN_SUCCESS;
-}
+ if (vnode_pager_get_throttle_io_limit(object->pager, &throttle_limit) == KERN_SUCCESS) {
+ if (max_length > throttle_limit)
+ max_length = throttle_limit;
+ }
+ if (pre_heat_size > max_length)
+ pre_heat_size = max_length;
-#if TASK_SWAPPER
-/*
- * vm_object_res_deallocate
- *
- * (recursively) decrement residence counts on vm objects and their shadows.
- * Called from vm_object_deallocate and when swapping out an object.
- *
- * The object is locked, and remains locked throughout the function,
- * even as we iterate down the shadow chain. Locks on intermediate objects
- * will be dropped, but not the original object.
- *
- * NOTE: this function used to use recursion, rather than iteration.
- */
+ if (behavior == VM_BEHAVIOR_DEFAULT && (pre_heat_size > min_ph_size)) {
-__private_extern__ void
-vm_object_res_deallocate(
- vm_object_t object)
-{
- vm_object_t orig_object = object;
- /*
- * Object is locked so it can be called directly
- * from vm_object_deallocate. Original object is never
- * unlocked.
- */
- assert(object->res_count > 0);
- while (--object->res_count == 0) {
- assert(object->ref_count >= object->res_count);
- vm_object_deactivate_all_pages(object);
- /* iterate on shadow, if present */
- if (object->shadow != VM_OBJECT_NULL) {
- vm_object_t tmp_object = object->shadow;
- vm_object_lock(tmp_object);
- if (object != orig_object)
- vm_object_unlock(object);
- object = tmp_object;
- assert(object->res_count > 0);
- } else
- break;
+ unsigned int consider_free = vm_page_free_count + vm_page_cleaned_count;
+
+ if (consider_free < vm_page_throttle_limit) {
+ pre_heat_size = trunc_page(pre_heat_size / 16);
+ } else if (consider_free < vm_page_free_target) {
+ pre_heat_size = trunc_page(pre_heat_size / 4);
+ }
+
+ if (pre_heat_size < min_ph_size)
+ pre_heat_size = min_ph_size;
}
- if (object != orig_object)
- vm_object_unlock(object);
-}
+ if (look_ahead == TRUE) {
+ if (look_behind == TRUE) {
+ /*
+ * if we get here its due to a random access...
+ * so we want to center the original fault address
+ * within the cluster we will issue... make sure
+ * to calculate 'head_size' as a multiple of PAGE_SIZE...
+ * 'pre_heat_size' is a multiple of PAGE_SIZE but not
+ * necessarily an even number of pages so we need to truncate
+ * the result to a PAGE_SIZE boundary
+ */
+ head_size = trunc_page(pre_heat_size / 2);
-/*
- * vm_object_res_reference
- *
- * Internal function to increment residence count on a vm object
- * and its shadows. It is called only from vm_object_reference, and
- * when swapping in a vm object, via vm_map_swap.
- *
- * The object is locked, and remains locked throughout the function,
- * even as we iterate down the shadow chain. Locks on intermediate objects
- * will be dropped, but not the original object.
- *
- * NOTE: this function used to use recursion, rather than iteration.
- */
+ if (target_start > head_size)
+ target_start -= head_size;
+ else
+ target_start = 0;
+
+ /*
+ * 'target_start' at this point represents the beginning offset
+ * of the cluster we are considering... 'orig_start' will be in
+ * the center of this cluster if we didn't have to clip the start
+ * due to running into the start of the file
+ */
+ }
+ if ((target_start + pre_heat_size) > object_size)
+ pre_heat_size = (vm_size_t)(round_page_64(object_size - target_start));
+ /*
+ * at this point caclulate the number of pages beyond the original fault
+ * address that we want to consider... this is guaranteed not to extend beyond
+ * the current EOF...
+ */
+ assert((vm_size_t)(orig_start - target_start) == (orig_start - target_start));
+ tail_size = pre_heat_size - (vm_size_t)(orig_start - target_start) - PAGE_SIZE;
+ } else {
+ if (pre_heat_size > target_start) {
+ /*
+ * since pre_heat_size is always smaller then 2^32,
+ * if it is larger then target_start (a 64 bit value)
+ * it is safe to clip target_start to 32 bits
+ */
+ pre_heat_size = (vm_size_t) target_start;
+ }
+ tail_size = 0;
+ }
+ assert( !(target_start & PAGE_MASK_64));
+ assert( !(pre_heat_size & PAGE_MASK_64));
+
+ if (pre_heat_size <= PAGE_SIZE)
+ goto out;
-__private_extern__ void
-vm_object_res_reference(
- vm_object_t object)
-{
- vm_object_t orig_object = object;
- /*
- * Object is locked, so this can be called directly
- * from vm_object_reference. This lock is never released.
- */
- while ((++object->res_count == 1) &&
- (object->shadow != VM_OBJECT_NULL)) {
- vm_object_t tmp_object = object->shadow;
+ if (look_behind == TRUE) {
+ /*
+ * take a look at the pages before the original
+ * faulting offset... recalculate this in case
+ * we had to clip 'pre_heat_size' above to keep
+ * from running past the EOF.
+ */
+ head_size = pre_heat_size - tail_size - PAGE_SIZE;
- assert(object->ref_count >= object->res_count);
- vm_object_lock(tmp_object);
- if (object != orig_object)
- vm_object_unlock(object);
- object = tmp_object;
+ for (offset = orig_start - PAGE_SIZE_64; head_size; offset -= PAGE_SIZE_64, head_size -= PAGE_SIZE) {
+ /*
+ * don't poke below the lowest offset
+ */
+ if (offset < fault_info->lo_offset)
+ break;
+ /*
+ * for external objects or internal objects w/o a pager,
+ * VM_COMPRESSOR_PAGER_STATE_GET will return VM_EXTERNAL_STATE_UNKNOWN
+ */
+ if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset) == VM_EXTERNAL_STATE_ABSENT) {
+ break;
+ }
+ if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
+ /*
+ * don't bridge resident pages
+ */
+ break;
+ }
+ *start = offset;
+ *length += PAGE_SIZE;
+ }
}
- if (object != orig_object)
- vm_object_unlock(object);
- assert(orig_object->ref_count >= orig_object->res_count);
-}
-#endif /* TASK_SWAPPER */
+ if (look_ahead == TRUE) {
+ for (offset = orig_start + PAGE_SIZE_64; tail_size; offset += PAGE_SIZE_64, tail_size -= PAGE_SIZE) {
+ /*
+ * don't poke above the highest offset
+ */
+ if (offset >= fault_info->hi_offset)
+ break;
+ assert(offset < object_size);
-/*
- * vm_object_reference:
- *
- * Gets another reference to the given object.
- */
-#ifdef vm_object_reference
-#undef vm_object_reference
-#endif
-__private_extern__ void
-vm_object_reference(
- register vm_object_t object)
-{
- if (object == VM_OBJECT_NULL)
- return;
+ /*
+ * for external objects or internal objects w/o a pager,
+ * VM_COMPRESSOR_PAGER_STATE_GET will return VM_EXTERNAL_STATE_UNKNOWN
+ */
+ if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset) == VM_EXTERNAL_STATE_ABSENT) {
+ break;
+ }
+ if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
+ /*
+ * don't bridge resident pages
+ */
+ break;
+ }
+ *length += PAGE_SIZE;
+ }
+ }
+out:
+ if (*length > max_length)
+ *length = max_length;
- vm_object_lock(object);
- assert(object->ref_count > 0);
- vm_object_reference_locked(object);
vm_object_unlock(object);
+
+ DTRACE_VM1(clustersize, vm_size_t, *length);
}
-#ifdef MACH_BSD
-/*
- * Scale the vm_object_cache
- * This is required to make sure that the vm_object_cache is big
- * enough to effectively cache the mapped file.
- * This is really important with UBC as all the regular file vnodes
- * have memory object associated with them. Havving this cache too
- * small results in rapid reclaim of vnodes and hurts performance a LOT!
- *
- * This is also needed as number of vnodes can be dynamically scaled.
- */
-kern_return_t
-adjust_vm_object_cache(
- __unused vm_size_t oval,
- __unused vm_size_t nval)
-{
-#if VM_OBJECT_CACHE
- vm_object_cached_max = nval;
- vm_object_cache_trim(FALSE);
-#endif
- return (KERN_SUCCESS);
-}
-#endif /* MACH_BSD */
-
/*
- * vm_object_transpose
- *
- * This routine takes two VM objects of the same size and exchanges
- * their backing store.
- * The objects should be "quiesced" via a UPL operation with UPL_SET_IO_WIRE
- * and UPL_BLOCK_ACCESS if they are referenced anywhere.
- *
- * The VM objects must not be locked by caller.
+ * Allow manipulation of individual page state. This is actually part of
+ * the UPL regimen but takes place on the VM object rather than on a UPL
*/
-unsigned int vm_object_transpose_count = 0;
+
kern_return_t
-vm_object_transpose(
- vm_object_t object1,
- vm_object_t object2,
- vm_object_size_t transpose_size)
+vm_object_page_op(
+ vm_object_t object,
+ vm_object_offset_t offset,
+ int ops,
+ ppnum_t *phys_entry,
+ int *flags)
{
- vm_object_t tmp_object;
- kern_return_t retval;
- boolean_t object1_locked, object2_locked;
- vm_page_t page;
- vm_object_offset_t page_offset;
- lck_mtx_t *hash_lck;
- vm_object_hash_entry_t hash_entry;
-
- tmp_object = VM_OBJECT_NULL;
- object1_locked = FALSE; object2_locked = FALSE;
+ vm_page_t dst_page;
- if (object1 == object2 ||
- object1 == VM_OBJECT_NULL ||
- object2 == VM_OBJECT_NULL) {
- /*
- * If the 2 VM objects are the same, there's
- * no point in exchanging their backing store.
- */
- retval = KERN_INVALID_VALUE;
- goto done;
- }
+ vm_object_lock(object);
- /*
- * Since we need to lock both objects at the same time,
- * make sure we always lock them in the same order to
- * avoid deadlocks.
- */
- if (object1 > object2) {
- tmp_object = object1;
- object1 = object2;
- object2 = tmp_object;
+ if(ops & UPL_POP_PHYSICAL) {
+ if(object->phys_contiguous) {
+ if (phys_entry) {
+ *phys_entry = (ppnum_t)
+ (object->vo_shadow_offset >> PAGE_SHIFT);
+ }
+ vm_object_unlock(object);
+ return KERN_SUCCESS;
+ } else {
+ vm_object_unlock(object);
+ return KERN_INVALID_OBJECT;
+ }
}
-
- /*
- * Allocate a temporary VM object to hold object1's contents
- * while we copy object2 to object1.
- */
- tmp_object = vm_object_allocate(transpose_size);
- vm_object_lock(tmp_object);
- tmp_object->can_persist = FALSE;
-
-
- /*
- * Grab control of the 1st VM object.
- */
- vm_object_lock(object1);
- object1_locked = TRUE;
- if (!object1->alive || object1->terminating ||
- object1->copy || object1->shadow || object1->shadowed ||
- object1->purgable != VM_PURGABLE_DENY) {
- /*
- * We don't deal with copy or shadow objects (yet).
- */
- retval = KERN_INVALID_VALUE;
- goto done;
+ if(object->phys_contiguous) {
+ vm_object_unlock(object);
+ return KERN_INVALID_OBJECT;
}
- /*
- * We're about to mess with the object's backing store and
- * taking a "paging_in_progress" reference wouldn't be enough
- * to prevent any paging activity on this object, so the caller should
- * have "quiesced" the objects beforehand, via a UPL operation with
- * UPL_SET_IO_WIRE (to make sure all the pages are there and wired)
- * and UPL_BLOCK_ACCESS (to mark the pages "busy").
- *
- * Wait for any paging operation to complete (but only paging, not
- * other kind of activities not linked to the pager). After we're
- * statisfied that there's no more paging in progress, we keep the
- * object locked, to guarantee that no one tries to access its pager.
- */
- vm_object_paging_only_wait(object1, THREAD_UNINT);
- /*
- * Same as above for the 2nd object...
- */
- vm_object_lock(object2);
- object2_locked = TRUE;
- if (! object2->alive || object2->terminating ||
- object2->copy || object2->shadow || object2->shadowed ||
- object2->purgable != VM_PURGABLE_DENY) {
- retval = KERN_INVALID_VALUE;
- goto done;
- }
- vm_object_paging_only_wait(object2, THREAD_UNINT);
+ while(TRUE) {
+ if((dst_page = vm_page_lookup(object,offset)) == VM_PAGE_NULL) {
+ vm_object_unlock(object);
+ return KERN_FAILURE;
+ }
+ /* Sync up on getting the busy bit */
+ if((dst_page->busy || dst_page->cleaning) &&
+ (((ops & UPL_POP_SET) &&
+ (ops & UPL_POP_BUSY)) || (ops & UPL_POP_DUMP))) {
+ /* someone else is playing with the page, we will */
+ /* have to wait */
+ PAGE_SLEEP(object, dst_page, THREAD_UNINT);
+ continue;
+ }
- if (object1->size != object2->size ||
- object1->size != transpose_size) {
- /*
- * If the 2 objects don't have the same size, we can't
- * exchange their backing stores or one would overflow.
- * If their size doesn't match the caller's
- * "transpose_size", we can't do it either because the
- * transpose operation will affect the entire span of
- * the objects.
- */
- retval = KERN_INVALID_VALUE;
- goto done;
- }
+ if (ops & UPL_POP_DUMP) {
+ if (dst_page->pmapped == TRUE)
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page));
+ VM_PAGE_FREE(dst_page);
+ break;
+ }
- /*
- * Transpose the lists of resident pages.
- * This also updates the resident_page_count and the memq_hint.
- */
- if (object1->phys_contiguous || queue_empty(&object1->memq)) {
- /*
- * No pages in object1, just transfer pages
- * from object2 to object1. No need to go through
- * an intermediate object.
- */
- while (!queue_empty(&object2->memq)) {
- page = (vm_page_t) queue_first(&object2->memq);
- vm_page_rename(page, object1, page->offset, FALSE);
+ if (flags) {
+ *flags = 0;
+
+ /* Get the condition of flags before requested ops */
+ /* are undertaken */
+
+ if(dst_page->dirty) *flags |= UPL_POP_DIRTY;
+ if(dst_page->free_when_done) *flags |= UPL_POP_PAGEOUT;
+ if(dst_page->precious) *flags |= UPL_POP_PRECIOUS;
+ if(dst_page->absent) *flags |= UPL_POP_ABSENT;
+ if(dst_page->busy) *flags |= UPL_POP_BUSY;
}
- assert(queue_empty(&object2->memq));
- } else if (object2->phys_contiguous || queue_empty(&object2->memq)) {
- /*
- * No pages in object2, just transfer pages
- * from object1 to object2. No need to go through
- * an intermediate object.
- */
- while (!queue_empty(&object1->memq)) {
- page = (vm_page_t) queue_first(&object1->memq);
- vm_page_rename(page, object2, page->offset, FALSE);
+
+ /* The caller should have made a call either contingent with */
+ /* or prior to this call to set UPL_POP_BUSY */
+ if(ops & UPL_POP_SET) {
+ /* The protection granted with this assert will */
+ /* not be complete. If the caller violates the */
+ /* convention and attempts to change page state */
+ /* without first setting busy we may not see it */
+ /* because the page may already be busy. However */
+ /* if such violations occur we will assert sooner */
+ /* or later. */
+ assert(dst_page->busy || (ops & UPL_POP_BUSY));
+ if (ops & UPL_POP_DIRTY) {
+ SET_PAGE_DIRTY(dst_page, FALSE);
+ }
+ if (ops & UPL_POP_PAGEOUT) dst_page->free_when_done = TRUE;
+ if (ops & UPL_POP_PRECIOUS) dst_page->precious = TRUE;
+ if (ops & UPL_POP_ABSENT) dst_page->absent = TRUE;
+ if (ops & UPL_POP_BUSY) dst_page->busy = TRUE;
}
- assert(queue_empty(&object1->memq));
- } else {
- /* transfer object1's pages to tmp_object */
- while (!queue_empty(&object1->memq)) {
- page = (vm_page_t) queue_first(&object1->memq);
- page_offset = page->offset;
- vm_page_remove(page, TRUE);
- page->offset = page_offset;
- queue_enter(&tmp_object->memq, page, vm_page_t, listq);
+
+ if(ops & UPL_POP_CLR) {
+ assert(dst_page->busy);
+ if (ops & UPL_POP_DIRTY) dst_page->dirty = FALSE;
+ if (ops & UPL_POP_PAGEOUT) dst_page->free_when_done = FALSE;
+ if (ops & UPL_POP_PRECIOUS) dst_page->precious = FALSE;
+ if (ops & UPL_POP_ABSENT) dst_page->absent = FALSE;
+ if (ops & UPL_POP_BUSY) {
+ dst_page->busy = FALSE;
+ PAGE_WAKEUP(dst_page);
+ }
}
- assert(queue_empty(&object1->memq));
- /* transfer object2's pages to object1 */
- while (!queue_empty(&object2->memq)) {
- page = (vm_page_t) queue_first(&object2->memq);
- vm_page_rename(page, object1, page->offset, FALSE);
+
+ if (dst_page->encrypted) {
+ /*
+ * ENCRYPTED SWAP:
+ * We need to decrypt this encrypted page before the
+ * caller can access its contents.
+ * But if the caller really wants to access the page's
+ * contents, they have to keep the page "busy".
+ * Otherwise, the page could get recycled or re-encrypted
+ * at any time.
+ */
+ if ((ops & UPL_POP_SET) && (ops & UPL_POP_BUSY) &&
+ dst_page->busy) {
+ /*
+ * The page is stable enough to be accessed by
+ * the caller, so make sure its contents are
+ * not encrypted.
+ */
+ vm_page_decrypt(dst_page, 0);
+ } else {
+ /*
+ * The page is not busy, so don't bother
+ * decrypting it, since anything could
+ * happen to it between now and when the
+ * caller wants to access it.
+ * We should not give the caller access
+ * to this page.
+ */
+ assert(!phys_entry);
+ }
}
- assert(queue_empty(&object2->memq));
- /* transfer tmp_object's pages to object1 */
- while (!queue_empty(&tmp_object->memq)) {
- page = (vm_page_t) queue_first(&tmp_object->memq);
- queue_remove(&tmp_object->memq, page,
- vm_page_t, listq);
- vm_page_insert(page, object2, page->offset);
+
+ if (phys_entry) {
+ /*
+ * The physical page number will remain valid
+ * only if the page is kept busy.
+ * ENCRYPTED SWAP: make sure we don't let the
+ * caller access an encrypted page.
+ */
+ assert(dst_page->busy);
+ assert(!dst_page->encrypted);
+ *phys_entry = VM_PAGE_GET_PHYS_PAGE(dst_page);
}
- assert(queue_empty(&tmp_object->memq));
+
+ break;
}
-#define __TRANSPOSE_FIELD(field) \
-MACRO_BEGIN \
- tmp_object->field = object1->field; \
- object1->field = object2->field; \
- object2->field = tmp_object->field; \
-MACRO_END
+ vm_object_unlock(object);
+ return KERN_SUCCESS;
+
+}
- /* "Lock" refers to the object not its contents */
- /* "size" should be identical */
- assert(object1->size == object2->size);
- /* "memq_hint" was updated above when transposing pages */
- /* "ref_count" refers to the object not its contents */
-#if TASK_SWAPPER
- /* "res_count" refers to the object not its contents */
-#endif
- /* "resident_page_count" was updated above when transposing pages */
- /* "wired_page_count" was updated above when transposing pages */
- /* "reusable_page_count" was updated above when transposing pages */
- /* there should be no "copy" */
- assert(!object1->copy);
- assert(!object2->copy);
- /* there should be no "shadow" */
- assert(!object1->shadow);
- assert(!object2->shadow);
- __TRANSPOSE_FIELD(shadow_offset); /* used by phys_contiguous objects */
- __TRANSPOSE_FIELD(pager);
- __TRANSPOSE_FIELD(paging_offset);
- __TRANSPOSE_FIELD(pager_control);
- /* update the memory_objects' pointers back to the VM objects */
- if (object1->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
- memory_object_control_collapse(object1->pager_control,
- object1);
+/*
+ * vm_object_range_op offers performance enhancement over
+ * vm_object_page_op for page_op functions which do not require page
+ * level state to be returned from the call. Page_op was created to provide
+ * a low-cost alternative to page manipulation via UPLs when only a single
+ * page was involved. The range_op call establishes the ability in the _op
+ * family of functions to work on multiple pages where the lack of page level
+ * state handling allows the caller to avoid the overhead of the upl structures.
+ */
+
+kern_return_t
+vm_object_range_op(
+ vm_object_t object,
+ vm_object_offset_t offset_beg,
+ vm_object_offset_t offset_end,
+ int ops,
+ uint32_t *range)
+{
+ vm_object_offset_t offset;
+ vm_page_t dst_page;
+
+ if (offset_end - offset_beg > (uint32_t) -1) {
+ /* range is too big and would overflow "*range" */
+ return KERN_INVALID_ARGUMENT;
+ }
+ if (object->resident_page_count == 0) {
+ if (range) {
+ if (ops & UPL_ROP_PRESENT) {
+ *range = 0;
+ } else {
+ *range = (uint32_t) (offset_end - offset_beg);
+ assert(*range == (offset_end - offset_beg));
+ }
+ }
+ return KERN_SUCCESS;
}
- if (object2->pager_control != MEMORY_OBJECT_CONTROL_NULL) {
- memory_object_control_collapse(object2->pager_control,
- object2);
+ vm_object_lock(object);
+
+ if (object->phys_contiguous) {
+ vm_object_unlock(object);
+ return KERN_INVALID_OBJECT;
}
- __TRANSPOSE_FIELD(copy_strategy);
- /* "paging_in_progress" refers to the object not its contents */
- assert(!object1->paging_in_progress);
- assert(!object2->paging_in_progress);
- assert(object1->activity_in_progress);
- assert(object2->activity_in_progress);
- /* "all_wanted" refers to the object not its contents */
- __TRANSPOSE_FIELD(pager_created);
- __TRANSPOSE_FIELD(pager_initialized);
- __TRANSPOSE_FIELD(pager_ready);
- __TRANSPOSE_FIELD(pager_trusted);
- __TRANSPOSE_FIELD(can_persist);
- __TRANSPOSE_FIELD(internal);
- __TRANSPOSE_FIELD(temporary);
- __TRANSPOSE_FIELD(private);
- __TRANSPOSE_FIELD(pageout);
- /* "alive" should be set */
- assert(object1->alive);
- assert(object2->alive);
- /* "purgeable" should be non-purgeable */
- assert(object1->purgable == VM_PURGABLE_DENY);
- assert(object2->purgable == VM_PURGABLE_DENY);
- /* "shadowed" refers to the the object not its contents */
- __TRANSPOSE_FIELD(silent_overwrite);
- __TRANSPOSE_FIELD(advisory_pageout);
- __TRANSPOSE_FIELD(true_share);
- /* "terminating" should not be set */
- assert(!object1->terminating);
- assert(!object2->terminating);
- __TRANSPOSE_FIELD(named);
- /* "shadow_severed" refers to the object not its contents */
- __TRANSPOSE_FIELD(phys_contiguous);
- __TRANSPOSE_FIELD(nophyscache);
- /* "cached_list.next" points to transposed object */
- object1->cached_list.next = (queue_entry_t) object2;
- object2->cached_list.next = (queue_entry_t) object1;
- /* "cached_list.prev" should be NULL */
- assert(object1->cached_list.prev == NULL);
- assert(object2->cached_list.prev == NULL);
- /* "msr_q" is linked to the object not its contents */
- assert(queue_empty(&object1->msr_q));
- assert(queue_empty(&object2->msr_q));
- __TRANSPOSE_FIELD(last_alloc);
- __TRANSPOSE_FIELD(sequential);
- __TRANSPOSE_FIELD(pages_created);
- __TRANSPOSE_FIELD(pages_used);
-#if MACH_PAGEMAP
- __TRANSPOSE_FIELD(existence_map);
-#endif
- __TRANSPOSE_FIELD(cow_hint);
-#if MACH_ASSERT
- __TRANSPOSE_FIELD(paging_object);
-#endif
- __TRANSPOSE_FIELD(wimg_bits);
- __TRANSPOSE_FIELD(code_signed);
- if (object1->hashed) {
- hash_lck = vm_object_hash_lock_spin(object2->pager);
- hash_entry = vm_object_hash_lookup(object2->pager, FALSE);
- assert(hash_entry != VM_OBJECT_HASH_ENTRY_NULL);
- hash_entry->object = object2;
- vm_object_hash_unlock(hash_lck);
+
+ offset = offset_beg & ~PAGE_MASK_64;
+
+ while (offset < offset_end) {
+ dst_page = vm_page_lookup(object, offset);
+ if (dst_page != VM_PAGE_NULL) {
+ if (ops & UPL_ROP_DUMP) {
+ if (dst_page->busy || dst_page->cleaning) {
+ /*
+ * someone else is playing with the
+ * page, we will have to wait
+ */
+ PAGE_SLEEP(object, dst_page, THREAD_UNINT);
+ /*
+ * need to relook the page up since it's
+ * state may have changed while we slept
+ * it might even belong to a different object
+ * at this point
+ */
+ continue;
+ }
+ if (dst_page->laundry)
+ vm_pageout_steal_laundry(dst_page, FALSE);
+
+ if (dst_page->pmapped == TRUE)
+ pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page));
+
+ VM_PAGE_FREE(dst_page);
+
+ } else if ((ops & UPL_ROP_ABSENT)
+ && (!dst_page->absent || dst_page->busy)) {
+ break;
+ }
+ } else if (ops & UPL_ROP_PRESENT)
+ break;
+
+ offset += PAGE_SIZE;
}
- if (object2->hashed) {
- hash_lck = vm_object_hash_lock_spin(object1->pager);
- hash_entry = vm_object_hash_lookup(object1->pager, FALSE);
- assert(hash_entry != VM_OBJECT_HASH_ENTRY_NULL);
- hash_entry->object = object1;
- vm_object_hash_unlock(hash_lck);
+ vm_object_unlock(object);
+
+ if (range) {
+ if (offset > offset_end)
+ offset = offset_end;
+ if(offset > offset_beg) {
+ *range = (uint32_t) (offset - offset_beg);
+ assert(*range == (offset - offset_beg));
+ } else {
+ *range = 0;
+ }
}
- __TRANSPOSE_FIELD(hashed);
- object1->transposed = TRUE;
- object2->transposed = TRUE;
- __TRANSPOSE_FIELD(mapping_in_progress);
- __TRANSPOSE_FIELD(volatile_empty);
- __TRANSPOSE_FIELD(volatile_fault);
- __TRANSPOSE_FIELD(all_reusable);
- assert(object1->blocked_access);
- assert(object2->blocked_access);
- assert(object1->__object2_unused_bits == 0);
- assert(object2->__object2_unused_bits == 0);
-#if UPL_DEBUG
- /* "uplq" refers to the object not its contents (see upl_transpose()) */
-#endif
- assert(object1->objq.next == NULL);
- assert(object1->objq.prev == NULL);
- assert(object2->objq.next == NULL);
- assert(object2->objq.prev == NULL);
+ return KERN_SUCCESS;
+}
-#undef __TRANSPOSE_FIELD
+/*
+ * Used to point a pager directly to a range of memory (when the pager may be associated
+ * with a non-device vnode). Takes a virtual address, an offset, and a size. We currently
+ * expect that the virtual address will denote the start of a range that is physically contiguous.
+ */
+kern_return_t pager_map_to_phys_contiguous(
+ memory_object_control_t object,
+ memory_object_offset_t offset,
+ addr64_t base_vaddr,
+ vm_size_t size)
+{
+ ppnum_t page_num;
+ boolean_t clobbered_private;
+ kern_return_t retval;
+ vm_object_t pager_object;
- retval = KERN_SUCCESS;
+ page_num = pmap_find_phys(kernel_pmap, base_vaddr);
-done:
- /*
- * Cleanup.
- */
- if (tmp_object != VM_OBJECT_NULL) {
- vm_object_unlock(tmp_object);
- /*
- * Re-initialize the temporary object to avoid
- * deallocating a real pager.
- */
- _vm_object_allocate(transpose_size, tmp_object);
- vm_object_deallocate(tmp_object);
- tmp_object = VM_OBJECT_NULL;
+ if (!page_num) {
+ retval = KERN_FAILURE;
+ goto out;
}
- if (object1_locked) {
- vm_object_unlock(object1);
- object1_locked = FALSE;
+ pager_object = memory_object_control_to_vm_object(object);
+
+ if (!pager_object) {
+ retval = KERN_FAILURE;
+ goto out;
}
- if (object2_locked) {
- vm_object_unlock(object2);
- object2_locked = FALSE;
+
+ clobbered_private = pager_object->private;
+ if (pager_object->private != TRUE) {
+ vm_object_lock(pager_object);
+ pager_object->private = TRUE;
+ vm_object_unlock(pager_object);
}
+ retval = vm_object_populate_with_private(pager_object, offset, page_num, size);
- vm_object_transpose_count++;
+ if (retval != KERN_SUCCESS) {
+ if (pager_object->private != clobbered_private) {
+ vm_object_lock(pager_object);
+ pager_object->private = clobbered_private;
+ vm_object_unlock(pager_object);
+ }
+ }
+out:
return retval;
}
+uint32_t scan_object_collision = 0;
-/*
- * vm_object_cluster_size
- *
- * Determine how big a cluster we should issue an I/O for...
- *
- * Inputs: *start == offset of page needed
- * *length == maximum cluster pager can handle
- * Outputs: *start == beginning offset of cluster
- * *length == length of cluster to try
- *
- * The original *start will be encompassed by the cluster
- *
- */
-extern int speculative_reads_disabled;
-#if CONFIG_EMBEDDED
-unsigned int preheat_pages_max = MAX_UPL_TRANSFER;
-unsigned int preheat_pages_min = 8;
-unsigned int preheat_pages_mult = 4;
-#else
-unsigned int preheat_pages_max = MAX_UPL_TRANSFER;
-unsigned int preheat_pages_min = 8;
-unsigned int preheat_pages_mult = 4;
+void
+vm_object_lock(vm_object_t object)
+{
+ if (object == vm_pageout_scan_wants_object) {
+ scan_object_collision++;
+ mutex_pause(2);
+ }
+ lck_rw_lock_exclusive(&object->Lock);
+#if DEVELOPMENT || DEBUG
+ object->Lock_owner = current_thread();
#endif
+}
-uint32_t pre_heat_scaling[MAX_UPL_TRANSFER + 1];
-uint32_t pre_heat_cluster[MAX_UPL_TRANSFER + 1];
-
-
-__private_extern__ void
-vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
- vm_size_t *length, vm_object_fault_info_t fault_info, uint32_t *io_streaming)
+boolean_t
+vm_object_lock_avoid(vm_object_t object)
{
- vm_size_t pre_heat_size;
- vm_size_t tail_size;
- vm_size_t head_size;
- vm_size_t max_length;
- vm_size_t cluster_size;
- vm_object_offset_t object_size;
- vm_object_offset_t orig_start;
- vm_object_offset_t target_start;
- vm_object_offset_t offset;
- vm_behavior_t behavior;
- boolean_t look_behind = TRUE;
- boolean_t look_ahead = TRUE;
- uint32_t throttle_limit;
- int sequential_run;
- int sequential_behavior = VM_BEHAVIOR_SEQUENTIAL;
- unsigned int max_ph_size;
- unsigned int min_ph_size;
- unsigned int ph_mult;
+ if (object == vm_pageout_scan_wants_object) {
+ scan_object_collision++;
+ return TRUE;
+ }
+ return FALSE;
+}
- assert( !(*length & PAGE_MASK));
- assert( !(*start & PAGE_MASK_64));
+boolean_t
+_vm_object_lock_try(vm_object_t object)
+{
+ boolean_t retval;
- if ( (ph_mult = preheat_pages_mult) < 1 )
- ph_mult = 1;
- if ( (min_ph_size = preheat_pages_min) < 1 )
- min_ph_size = 1;
- if ( (max_ph_size = preheat_pages_max) > MAX_UPL_TRANSFER )
- max_ph_size = MAX_UPL_TRANSFER;
-
- if ( (max_length = *length) > (max_ph_size * PAGE_SIZE) )
- max_length = (max_ph_size * PAGE_SIZE);
+ retval = lck_rw_try_lock_exclusive(&object->Lock);
+#if DEVELOPMENT || DEBUG
+ if (retval == TRUE)
+ object->Lock_owner = current_thread();
+#endif
+ return (retval);
+}
+boolean_t
+vm_object_lock_try(vm_object_t object)
+{
/*
- * we'll always return a cluster size of at least
- * 1 page, since the original fault must always
- * be processed
+ * Called from hibernate path so check before blocking.
*/
- *length = PAGE_SIZE;
- *io_streaming = 0;
+ if (vm_object_lock_avoid(object) && ml_get_interrupts_enabled() && get_preemption_level()==0) {
+ mutex_pause(2);
+ }
+ return _vm_object_lock_try(object);
+}
- if (speculative_reads_disabled || fault_info == NULL || max_length == 0) {
- /*
- * no cluster... just fault the page in
- */
- return;
+void
+vm_object_lock_shared(vm_object_t object)
+{
+ if (vm_object_lock_avoid(object)) {
+ mutex_pause(2);
}
- orig_start = *start;
- target_start = orig_start;
- cluster_size = round_page(fault_info->cluster_size);
- behavior = fault_info->behavior;
+ lck_rw_lock_shared(&object->Lock);
+}
- vm_object_lock(object);
+boolean_t
+vm_object_lock_try_shared(vm_object_t object)
+{
+ if (vm_object_lock_avoid(object)) {
+ mutex_pause(2);
+ }
+ return (lck_rw_try_lock_shared(&object->Lock));
+}
- if (object->internal)
- object_size = object->size;
- else if (object->pager != MEMORY_OBJECT_NULL)
- vnode_pager_get_object_size(object->pager, &object_size);
- else
- goto out; /* pager is gone for this object, nothing more to do */
+boolean_t
+vm_object_lock_upgrade(vm_object_t object)
+{ boolean_t retval;
- object_size = round_page_64(object_size);
+ retval = lck_rw_lock_shared_to_exclusive(&object->Lock);
+#if DEVELOPMENT || DEBUG
+ if (retval == TRUE)
+ object->Lock_owner = current_thread();
+#endif
+ return (retval);
+}
- if (orig_start >= object_size) {
- /*
- * fault occurred beyond the EOF...
- * we need to punt w/o changing the
- * starting offset
- */
- goto out;
+void
+vm_object_unlock(vm_object_t object)
+{
+#if DEVELOPMENT || DEBUG
+ if (object->Lock_owner) {
+ if (object->Lock_owner != current_thread())
+ panic("vm_object_unlock: not owner - %p\n", object);
+ object->Lock_owner = 0;
}
- if (object->pages_used > object->pages_created) {
- /*
- * must have wrapped our 32 bit counters
- * so reset
- */
- object->pages_used = object->pages_created = 0;
+#endif
+ lck_rw_done(&object->Lock);
+}
+
+
+unsigned int vm_object_change_wimg_mode_count = 0;
+
+/*
+ * The object must be locked
+ */
+void
+vm_object_change_wimg_mode(vm_object_t object, unsigned int wimg_mode)
+{
+ vm_page_t p;
+
+ vm_object_lock_assert_exclusive(object);
+
+ vm_object_paging_wait(object, THREAD_UNINT);
+
+ vm_page_queue_iterate(&object->memq, p, vm_page_t, listq) {
+
+ if (!p->fictitious)
+ pmap_set_cache_attributes(VM_PAGE_GET_PHYS_PAGE(p), wimg_mode);
}
- if ((sequential_run = object->sequential)) {
- if (sequential_run < 0) {
- sequential_behavior = VM_BEHAVIOR_RSEQNTL;
- sequential_run = 0 - sequential_run;
- } else {
- sequential_behavior = VM_BEHAVIOR_SEQUENTIAL;
- }
+ if (wimg_mode == VM_WIMG_USE_DEFAULT)
+ object->set_cache_attr = FALSE;
+ else
+ object->set_cache_attr = TRUE;
+
+ object->wimg_bits = wimg_mode;
+
+ vm_object_change_wimg_mode_count++;
+}
+
+#if CONFIG_FREEZE
+
+/*
+ * This routine does the "relocation" of previously
+ * compressed pages belonging to this object that are
+ * residing in a number of compressed segments into
+ * a set of compressed segments dedicated to hold
+ * compressed pages belonging to this object.
+ */
+
+extern void *freezer_chead;
+extern char *freezer_compressor_scratch_buf;
+extern int c_freezer_compression_count;
+extern AbsoluteTime c_freezer_last_yield_ts;
+
+#define MAX_FREE_BATCH 32
+#define FREEZER_DUTY_CYCLE_ON_MS 5
+#define FREEZER_DUTY_CYCLE_OFF_MS 5
+
+static int c_freezer_should_yield(void);
+
+
+static int
+c_freezer_should_yield()
+{
+ AbsoluteTime cur_time;
+ uint64_t nsecs;
+
+ assert(c_freezer_last_yield_ts);
+ clock_get_uptime(&cur_time);
+
+ SUB_ABSOLUTETIME(&cur_time, &c_freezer_last_yield_ts);
+ absolutetime_to_nanoseconds(cur_time, &nsecs);
+
+ if (nsecs > 1000 * 1000 * FREEZER_DUTY_CYCLE_ON_MS)
+ return (1);
+ return (0);
+}
+
+
+void
+vm_object_compressed_freezer_done()
+{
+ vm_compressor_finished_filling(&freezer_chead);
+}
+
+
+void
+vm_object_compressed_freezer_pageout(
+ vm_object_t object)
+{
+ vm_page_t p;
+ vm_page_t local_freeq = NULL;
+ int local_freed = 0;
+ kern_return_t retval = KERN_SUCCESS;
+ int obj_resident_page_count_snapshot = 0;
+
+ assert(object != VM_OBJECT_NULL);
+ assert(object->internal);
+
+ vm_object_lock(object);
+
+ if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) {
+
+ if (!object->pager_initialized) {
- }
- switch(behavior) {
+ vm_object_collapse(object, (vm_object_offset_t) 0, TRUE);
- default:
- behavior = VM_BEHAVIOR_DEFAULT;
+ if (!object->pager_initialized)
+ vm_object_compressor_pager_create(object);
+ }
- case VM_BEHAVIOR_DEFAULT:
- if (object->internal && fault_info->user_tag == VM_MEMORY_STACK)
- goto out;
+ if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) {
+ vm_object_unlock(object);
+ return;
+ }
+ }
+
+ if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
+ vm_object_offset_t curr_offset = 0;
- if (sequential_run >= (3 * PAGE_SIZE)) {
- pre_heat_size = sequential_run + PAGE_SIZE;
+ /*
+ * Go through the object and make sure that any
+ * previously compressed pages are relocated into
+ * a compressed segment associated with our "freezer_chead".
+ */
+ while (curr_offset < object->vo_size) {
- if (sequential_behavior == VM_BEHAVIOR_SEQUENTIAL)
- look_behind = FALSE;
- else
- look_ahead = FALSE;
+ curr_offset = vm_compressor_pager_next_compressed(object->pager, curr_offset);
+
+ if (curr_offset == (vm_object_offset_t) -1)
+ break;
- *io_streaming = 1;
- } else {
+ retval = vm_compressor_pager_relocate(object->pager, curr_offset, &freezer_chead);
- if (object->pages_created < 32 * ph_mult) {
- /*
- * prime the pump
- */
- pre_heat_size = PAGE_SIZE * 8 * ph_mult;
- break;
- }
- /*
- * Linear growth in PH size: The maximum size is max_length...
- * this cacluation will result in a size that is neither a
- * power of 2 nor a multiple of PAGE_SIZE... so round
- * it up to the nearest PAGE_SIZE boundary
- */
- pre_heat_size = (ph_mult * (max_length * object->pages_used) / object->pages_created);
-
- if (pre_heat_size < PAGE_SIZE * min_ph_size)
- pre_heat_size = PAGE_SIZE * min_ph_size;
- else
- pre_heat_size = round_page(pre_heat_size);
+ if (retval != KERN_SUCCESS)
+ break;
+
+ curr_offset += PAGE_SIZE_64;
}
- break;
+ }
- case VM_BEHAVIOR_RANDOM:
- if ((pre_heat_size = cluster_size) <= PAGE_SIZE)
- goto out;
- break;
+ /*
+ * We can't hold the object lock while heading down into the compressed pager
+ * layer because we might need the kernel map lock down there to allocate new
+ * compressor data structures. And if this same object is mapped in the kernel
+ * and there's a fault on it, then that thread will want the object lock while
+ * holding the kernel map lock.
+ *
+ * Since we are going to drop/grab the object lock repeatedly, we must make sure
+ * we won't be stuck in an infinite loop if the same page(s) keep getting
+ * decompressed. So we grab a snapshot of the number of pages in the object and
+ * we won't process any more than that number of pages.
+ */
- case VM_BEHAVIOR_SEQUENTIAL:
- if ((pre_heat_size = cluster_size) == 0)
- pre_heat_size = sequential_run + PAGE_SIZE;
- look_behind = FALSE;
- *io_streaming = 1;
+ obj_resident_page_count_snapshot = object->resident_page_count;
- break;
+ vm_object_activity_begin(object);
- case VM_BEHAVIOR_RSEQNTL:
- if ((pre_heat_size = cluster_size) == 0)
- pre_heat_size = sequential_run + PAGE_SIZE;
- look_ahead = FALSE;
- *io_streaming = 1;
+ while ((obj_resident_page_count_snapshot--) && !vm_page_queue_empty(&object->memq)) {
- break;
+ p = (vm_page_t)vm_page_queue_first(&object->memq);
- }
- throttle_limit = (uint32_t) max_length;
- assert(throttle_limit == max_length);
+ KERNEL_DEBUG(0xe0430004 | DBG_FUNC_START, object, local_freed, 0, 0, 0);
- if (vnode_pager_check_hard_throttle(object->pager, &throttle_limit, *io_streaming) == KERN_SUCCESS) {
- if (max_length > throttle_limit)
- max_length = throttle_limit;
- }
- if (pre_heat_size > max_length)
- pre_heat_size = max_length;
+ vm_page_lockspin_queues();
- if (behavior == VM_BEHAVIOR_DEFAULT) {
- if (vm_page_free_count < vm_page_throttle_limit)
- pre_heat_size = trunc_page(pre_heat_size / 8);
- else if (vm_page_free_count < vm_page_free_target)
- pre_heat_size = trunc_page(pre_heat_size / 2);
+ if (p->cleaning || p->fictitious || p->busy || p->absent || p->unusual || p->error || VM_PAGE_WIRED(p)) {
- if (pre_heat_size <= PAGE_SIZE)
- goto out;
- }
- if (look_ahead == TRUE) {
- if (look_behind == TRUE) {
- /*
- * if we get here its due to a random access...
- * so we want to center the original fault address
- * within the cluster we will issue... make sure
- * to calculate 'head_size' as a multiple of PAGE_SIZE...
- * 'pre_heat_size' is a multiple of PAGE_SIZE but not
- * necessarily an even number of pages so we need to truncate
- * the result to a PAGE_SIZE boundary
- */
- head_size = trunc_page(pre_heat_size / 2);
+ vm_page_unlock_queues();
- if (target_start > head_size)
- target_start -= head_size;
- else
- target_start = 0;
+ KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 1, 0, 0);
+
+ vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+ vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
+
+ continue;
+ }
+ if (p->pmapped == TRUE) {
+ int refmod_state, pmap_flags;
+
+ if (p->dirty || p->precious) {
+ pmap_flags = PMAP_OPTIONS_COMPRESSOR;
+ } else {
+ pmap_flags = PMAP_OPTIONS_COMPRESSOR_IFF_MODIFIED;
+ }
+
+ refmod_state = pmap_disconnect_options(VM_PAGE_GET_PHYS_PAGE(p), pmap_flags, NULL);
+ if (refmod_state & VM_MEM_MODIFIED) {
+ SET_PAGE_DIRTY(p, FALSE);
+ }
+ }
+
+ if (p->dirty == FALSE && p->precious == FALSE) {
/*
- * 'target_start' at this point represents the beginning offset
- * of the cluster we are considering... 'orig_start' will be in
- * the center of this cluster if we didn't have to clip the start
- * due to running into the start of the file
+ * Clean and non-precious page.
*/
+ vm_page_unlock_queues();
+ VM_PAGE_FREE(p);
+
+ KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 2, 0, 0);
+ continue;
}
- if ((target_start + pre_heat_size) > object_size)
- pre_heat_size = (vm_size_t)(round_page_64(object_size - target_start));
+
+ if (p->laundry)
+ vm_pageout_steal_laundry(p, TRUE);
+
+ vm_page_queues_remove(p, TRUE);
+
+ vm_page_unlock_queues();
+
+
/*
- * at this point caclulate the number of pages beyond the original fault
- * address that we want to consider... this is guaranteed not to extend beyond
- * the current EOF...
+ * In case the compressor fails to compress this page, we need it at
+ * the back of the object memq so that we don't keep trying to process it.
+ * Make the move here while we have the object lock held.
*/
- assert((vm_size_t)(orig_start - target_start) == (orig_start - target_start));
- tail_size = pre_heat_size - (vm_size_t)(orig_start - target_start) - PAGE_SIZE;
- } else {
- if (pre_heat_size > target_start)
- pre_heat_size = (vm_size_t) target_start; /* XXX: 32-bit vs 64-bit ? Joe ? */
- tail_size = 0;
- }
- assert( !(target_start & PAGE_MASK_64));
- assert( !(pre_heat_size & PAGE_MASK));
-
- pre_heat_scaling[pre_heat_size / PAGE_SIZE]++;
- if (pre_heat_size <= PAGE_SIZE)
- goto out;
+ vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+ vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
- if (look_behind == TRUE) {
- /*
- * take a look at the pages before the original
- * faulting offset... recalculate this in case
- * we had to clip 'pre_heat_size' above to keep
- * from running past the EOF.
+ /*
+ * Grab an activity_in_progress here for vm_pageout_compress_page() to consume.
+ *
+ * Mark the page busy so no one messes with it while we have the object lock dropped.
*/
- head_size = pre_heat_size - tail_size - PAGE_SIZE;
- for (offset = orig_start - PAGE_SIZE_64; head_size; offset -= PAGE_SIZE_64, head_size -= PAGE_SIZE) {
- /*
- * don't poke below the lowest offset
- */
- if (offset < fault_info->lo_offset)
- break;
- /*
- * for external objects and internal objects w/o an existence map
- * vm_externl_state_get will return VM_EXTERNAL_STATE_UNKNOWN
+ p->busy = TRUE;
+
+ vm_object_activity_begin(object);
+
+ vm_object_unlock(object);
+
+ /*
+ * arg3 == FALSE tells vm_pageout_compress_page that we don't hold the object lock and the pager may not be initialized.
+ */
+ if (vm_pageout_compress_page(&freezer_chead, freezer_compressor_scratch_buf, p, FALSE) == KERN_SUCCESS) {
+ /*
+ * page has already been un-tabled from the object via 'vm_page_remove'
*/
-#if MACH_PAGEMAP
- if (vm_external_state_get(object->existence_map, offset) == VM_EXTERNAL_STATE_ABSENT) {
- /*
- * we know for a fact that the pager can't provide the page
- * so don't include it or any pages beyond it in this cluster
- */
- break;
- }
-#endif
- if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
- /*
- * don't bridge resident pages
- */
- break;
+ p->snext = local_freeq;
+ local_freeq = p;
+ local_freed++;
+
+ if (local_freed >= MAX_FREE_BATCH) {
+
+ vm_page_free_list(local_freeq, TRUE);
+
+ local_freeq = NULL;
+ local_freed = 0;
}
- *start = offset;
- *length += PAGE_SIZE;
+ c_freezer_compression_count++;
}
- }
- if (look_ahead == TRUE) {
- for (offset = orig_start + PAGE_SIZE_64; tail_size; offset += PAGE_SIZE_64, tail_size -= PAGE_SIZE) {
- /*
- * don't poke above the highest offset
- */
- if (offset >= fault_info->hi_offset)
- break;
- assert(offset < object_size);
+ KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 0, 0, 0);
- /*
- * for external objects and internal objects w/o an existence map
- * vm_externl_state_get will return VM_EXTERNAL_STATE_UNKNOWN
- */
-#if MACH_PAGEMAP
- if (vm_external_state_get(object->existence_map, offset) == VM_EXTERNAL_STATE_ABSENT) {
- /*
- * we know for a fact that the pager can't provide the page
- * so don't include it or any pages beyond it in this cluster
- */
- break;
- }
-#endif
- if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
- /*
- * don't bridge resident pages
- */
- break;
- }
- *length += PAGE_SIZE;
+ if (local_freed == 0 && c_freezer_should_yield()) {
+
+ thread_yield_internal(FREEZER_DUTY_CYCLE_OFF_MS);
+ clock_get_uptime(&c_freezer_last_yield_ts);
}
+
+ vm_object_lock(object);
}
-out:
- if (*length > max_length)
- *length = max_length;
- pre_heat_cluster[*length / PAGE_SIZE]++;
+ if (local_freeq) {
+ vm_page_free_list(local_freeq, TRUE);
+
+ local_freeq = NULL;
+ local_freed = 0;
+ }
+
+ vm_object_activity_end(object);
vm_object_unlock(object);
+
+ if (c_freezer_should_yield()) {
+
+ thread_yield_internal(FREEZER_DUTY_CYCLE_OFF_MS);
+ clock_get_uptime(&c_freezer_last_yield_ts);
+ }
}
+#endif /* CONFIG_FREEZE */
-/*
- * Allow manipulation of individual page state. This is actually part of
- * the UPL regimen but takes place on the VM object rather than on a UPL
- */
-kern_return_t
-vm_object_page_op(
- vm_object_t object,
- vm_object_offset_t offset,
- int ops,
- ppnum_t *phys_entry,
- int *flags)
+void
+vm_object_pageout(
+ vm_object_t object)
{
- vm_page_t dst_page;
+ vm_page_t p, next;
+ struct vm_pageout_queue *iq;
+ boolean_t need_unlock = TRUE;
+
+ if (!VM_CONFIG_COMPRESSOR_IS_PRESENT)
+ return;
+ iq = &vm_pageout_queue_internal;
+
+ assert(object != VM_OBJECT_NULL );
+
vm_object_lock(object);
- if(ops & UPL_POP_PHYSICAL) {
- if(object->phys_contiguous) {
- if (phys_entry) {
- *phys_entry = (ppnum_t)
- (object->shadow_offset >> PAGE_SHIFT);
- }
- vm_object_unlock(object);
- return KERN_SUCCESS;
- } else {
- vm_object_unlock(object);
- return KERN_INVALID_OBJECT;
- }
- }
- if(object->phys_contiguous) {
+ if (!object->internal ||
+ object->terminating ||
+ !object->alive) {
vm_object_unlock(object);
- return KERN_INVALID_OBJECT;
+ return;
}
- while(TRUE) {
- if((dst_page = vm_page_lookup(object,offset)) == VM_PAGE_NULL) {
- vm_object_unlock(object);
- return KERN_FAILURE;
- }
+ if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) {
+
+ if (!object->pager_initialized) {
- /* Sync up on getting the busy bit */
- if((dst_page->busy || dst_page->cleaning) &&
- (((ops & UPL_POP_SET) &&
- (ops & UPL_POP_BUSY)) || (ops & UPL_POP_DUMP))) {
- /* someone else is playing with the page, we will */
- /* have to wait */
- PAGE_SLEEP(object, dst_page, THREAD_UNINT);
- continue;
+ vm_object_collapse(object, (vm_object_offset_t) 0, TRUE);
+
+ if (!object->pager_initialized)
+ vm_object_compressor_pager_create(object);
}
- if (ops & UPL_POP_DUMP) {
- if (dst_page->pmapped == TRUE)
- pmap_disconnect(dst_page->phys_page);
+ if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) {
+ vm_object_unlock(object);
+ return;
+ }
+ }
+
+ReScan:
+ next = (vm_page_t)vm_page_queue_first(&object->memq);
- VM_PAGE_FREE(dst_page);
- break;
+ while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next)) {
+ p = next;
+ next = (vm_page_t)vm_page_queue_next(&next->listq);
+
+ assert(p->vm_page_q_state != VM_PAGE_ON_FREE_Q);
+
+ if ((p->vm_page_q_state == VM_PAGE_ON_THROTTLED_Q) ||
+ p->encrypted_cleaning ||
+ p->cleaning ||
+ p->laundry ||
+ p->busy ||
+ p->absent ||
+ p->error ||
+ p->fictitious ||
+ VM_PAGE_WIRED(p)) {
+ /*
+ * Page is already being cleaned or can't be cleaned.
+ */
+ continue;
}
- if (flags) {
- *flags = 0;
+ /* Throw to the pageout queue */
- /* Get the condition of flags before requested ops */
- /* are undertaken */
+ vm_page_lockspin_queues();
+ need_unlock = TRUE;
- if(dst_page->dirty) *flags |= UPL_POP_DIRTY;
- if(dst_page->pageout) *flags |= UPL_POP_PAGEOUT;
- if(dst_page->precious) *flags |= UPL_POP_PRECIOUS;
- if(dst_page->absent) *flags |= UPL_POP_ABSENT;
- if(dst_page->busy) *flags |= UPL_POP_BUSY;
+ if (vm_compressor_low_on_space()) {
+ vm_page_unlock_queues();
+ break;
}
- /* The caller should have made a call either contingent with */
- /* or prior to this call to set UPL_POP_BUSY */
- if(ops & UPL_POP_SET) {
- /* The protection granted with this assert will */
- /* not be complete. If the caller violates the */
- /* convention and attempts to change page state */
- /* without first setting busy we may not see it */
- /* because the page may already be busy. However */
- /* if such violations occur we will assert sooner */
- /* or later. */
- assert(dst_page->busy || (ops & UPL_POP_BUSY));
- if (ops & UPL_POP_DIRTY) dst_page->dirty = TRUE;
- if (ops & UPL_POP_PAGEOUT) dst_page->pageout = TRUE;
- if (ops & UPL_POP_PRECIOUS) dst_page->precious = TRUE;
- if (ops & UPL_POP_ABSENT) dst_page->absent = TRUE;
- if (ops & UPL_POP_BUSY) dst_page->busy = TRUE;
- }
+ if (VM_PAGE_Q_THROTTLED(iq)) {
+
+ iq->pgo_draining = TRUE;
+
+ assert_wait((event_t) (&iq->pgo_laundry + 1),
+ THREAD_INTERRUPTIBLE);
+ vm_page_unlock_queues();
+ vm_object_unlock(object);
+
+ thread_block(THREAD_CONTINUE_NULL);
- if(ops & UPL_POP_CLR) {
- assert(dst_page->busy);
- if (ops & UPL_POP_DIRTY) dst_page->dirty = FALSE;
- if (ops & UPL_POP_PAGEOUT) dst_page->pageout = FALSE;
- if (ops & UPL_POP_PRECIOUS) dst_page->precious = FALSE;
- if (ops & UPL_POP_ABSENT) dst_page->absent = FALSE;
- if (ops & UPL_POP_BUSY) {
- dst_page->busy = FALSE;
- PAGE_WAKEUP(dst_page);
- }
+ vm_object_lock(object);
+ goto ReScan;
}
- if (dst_page->encrypted) {
+ assert(!p->fictitious);
+ assert(!p->busy);
+ assert(!p->absent);
+ assert(!p->unusual);
+ assert(!p->error);
+ assert(!VM_PAGE_WIRED(p));
+ assert(!p->cleaning);
+
+ if (p->pmapped == TRUE) {
+ int refmod_state;
+ int pmap_options;
+
/*
- * ENCRYPTED SWAP:
- * We need to decrypt this encrypted page before the
- * caller can access its contents.
- * But if the caller really wants to access the page's
- * contents, they have to keep the page "busy".
- * Otherwise, the page could get recycled or re-encrypted
- * at any time.
+ * Tell pmap the page should be accounted
+ * for as "compressed" if it's been modified.
*/
- if ((ops & UPL_POP_SET) && (ops & UPL_POP_BUSY) &&
- dst_page->busy) {
- /*
- * The page is stable enough to be accessed by
- * the caller, so make sure its contents are
- * not encrypted.
- */
- vm_page_decrypt(dst_page, 0);
- } else {
+ pmap_options =
+ PMAP_OPTIONS_COMPRESSOR_IFF_MODIFIED;
+ if (p->dirty || p->precious) {
/*
- * The page is not busy, so don't bother
- * decrypting it, since anything could
- * happen to it between now and when the
- * caller wants to access it.
- * We should not give the caller access
- * to this page.
+ * We already know it's been modified,
+ * so tell pmap to account for it
+ * as "compressed".
*/
- assert(!phys_entry);
+ pmap_options = PMAP_OPTIONS_COMPRESSOR;
+ }
+ refmod_state = pmap_disconnect_options(VM_PAGE_GET_PHYS_PAGE(p),
+ pmap_options,
+ NULL);
+ if (refmod_state & VM_MEM_MODIFIED) {
+ SET_PAGE_DIRTY(p, FALSE);
}
}
- if (phys_entry) {
- /*
- * The physical page number will remain valid
- * only if the page is kept busy.
- * ENCRYPTED SWAP: make sure we don't let the
- * caller access an encrypted page.
- */
- assert(dst_page->busy);
- assert(!dst_page->encrypted);
- *phys_entry = dst_page->phys_page;
+ if (!p->dirty && !p->precious) {
+ vm_page_unlock_queues();
+ VM_PAGE_FREE(p);
+ continue;
}
- break;
+ vm_page_queues_remove(p, TRUE);
+
+ if (vm_pageout_cluster(p, FALSE, TRUE))
+ need_unlock = FALSE;
+
+ if (need_unlock == TRUE)
+ vm_page_unlock_queues();
}
vm_object_unlock(object);
- return KERN_SUCCESS;
-
}
-/*
- * vm_object_range_op offers performance enhancement over
- * vm_object_page_op for page_op functions which do not require page
- * level state to be returned from the call. Page_op was created to provide
- * a low-cost alternative to page manipulation via UPLs when only a single
- * page was involved. The range_op call establishes the ability in the _op
- * family of functions to work on multiple pages where the lack of page level
- * state handling allows the caller to avoid the overhead of the upl structures.
- */
-kern_return_t
-vm_object_range_op(
- vm_object_t object,
- vm_object_offset_t offset_beg,
- vm_object_offset_t offset_end,
- int ops,
- uint32_t *range)
+#if CONFIG_IOSCHED
+void
+vm_page_request_reprioritize(vm_object_t o, uint64_t blkno, uint32_t len, int prio)
{
- vm_object_offset_t offset;
- vm_page_t dst_page;
+ io_reprioritize_req_t req;
+ struct vnode *devvp = NULL;
- if (offset_end - offset_beg > (uint32_t) -1) {
- /* range is too big and would overflow "*range" */
- return KERN_INVALID_ARGUMENT;
- }
- if (object->resident_page_count == 0) {
- if (range) {
- if (ops & UPL_ROP_PRESENT) {
- *range = 0;
- } else {
- *range = (uint32_t) (offset_end - offset_beg);
- assert(*range == (offset_end - offset_beg));
- }
- }
- return KERN_SUCCESS;
- }
- vm_object_lock(object);
+ if(vnode_pager_get_object_devvp(o->pager, (uintptr_t *)&devvp) != KERN_SUCCESS)
+ return;
+
+ /*
+ * Create the request for I/O reprioritization.
+ * We use the noblock variant of zalloc because we're holding the object
+ * lock here and we could cause a deadlock in low memory conditions.
+ */
+ req = (io_reprioritize_req_t)zalloc_noblock(io_reprioritize_req_zone);
+ if (req == NULL)
+ return;
+ req->blkno = blkno;
+ req->len = len;
+ req->priority = prio;
+ req->devvp = devvp;
- if (object->phys_contiguous) {
- vm_object_unlock(object);
- return KERN_INVALID_OBJECT;
+ /* Insert request into the reprioritization list */
+ IO_REPRIORITIZE_LIST_LOCK();
+ queue_enter(&io_reprioritize_list, req, io_reprioritize_req_t, io_reprioritize_list);
+ IO_REPRIORITIZE_LIST_UNLOCK();
+
+ /* Wakeup reprioritize thread */
+ IO_REPRIO_THREAD_WAKEUP();
+
+ return;
+}
+
+void
+vm_decmp_upl_reprioritize(upl_t upl, int prio)
+{
+ int offset;
+ vm_object_t object;
+ io_reprioritize_req_t req;
+ struct vnode *devvp = NULL;
+ uint64_t blkno;
+ uint32_t len;
+ upl_t io_upl;
+ uint64_t *io_upl_reprio_info;
+ int io_upl_size;
+
+ if ((upl->flags & UPL_TRACKED_BY_OBJECT) == 0 || (upl->flags & UPL_EXPEDITE_SUPPORTED) == 0)
+ return;
+
+ /*
+ * We dont want to perform any allocations with the upl lock held since that might
+ * result in a deadlock. If the system is low on memory, the pageout thread would
+ * try to pageout stuff and might wait on this lock. If we are waiting for the memory to
+ * be freed up by the pageout thread, it would be a deadlock.
+ */
+
+
+ /* First step is just to get the size of the upl to find out how big the reprio info is */
+ if(!upl_try_lock(upl))
+ return;
+
+ if (upl->decmp_io_upl == NULL) {
+ /* The real I/O upl was destroyed by the time we came in here. Nothing to do. */
+ upl_unlock(upl);
+ return;
}
+
+ io_upl = upl->decmp_io_upl;
+ assert((io_upl->flags & UPL_DECMP_REAL_IO) != 0);
+ io_upl_size = io_upl->size;
+ upl_unlock(upl);
- offset = offset_beg & ~PAGE_MASK_64;
+ /* Now perform the allocation */
+ io_upl_reprio_info = (uint64_t *)kalloc(sizeof(uint64_t) * (io_upl_size / PAGE_SIZE));
+ if (io_upl_reprio_info == NULL)
+ return;
- while (offset < offset_end) {
- dst_page = vm_page_lookup(object, offset);
- if (dst_page != VM_PAGE_NULL) {
- if (ops & UPL_ROP_DUMP) {
- if (dst_page->busy || dst_page->cleaning) {
- /*
- * someone else is playing with the
- * page, we will have to wait
- */
- PAGE_SLEEP(object, dst_page, THREAD_UNINT);
- /*
- * need to relook the page up since it's
- * state may have changed while we slept
- * it might even belong to a different object
- * at this point
- */
- continue;
- }
- if (dst_page->pmapped == TRUE)
- pmap_disconnect(dst_page->phys_page);
+ /* Now again take the lock, recheck the state and grab out the required info */
+ if(!upl_try_lock(upl))
+ goto out;
- VM_PAGE_FREE(dst_page);
+ if (upl->decmp_io_upl == NULL || upl->decmp_io_upl != io_upl) {
+ /* The real I/O upl was destroyed by the time we came in here. Nothing to do. */
+ upl_unlock(upl);
+ goto out;
+ }
+ memcpy(io_upl_reprio_info, io_upl->upl_reprio_info, sizeof(uint64_t) * (io_upl_size / PAGE_SIZE));
- } else if ((ops & UPL_ROP_ABSENT) && !dst_page->absent)
- break;
- } else if (ops & UPL_ROP_PRESENT)
- break;
+ /* Get the VM object for this UPL */
+ if (io_upl->flags & UPL_SHADOWED) {
+ object = io_upl->map_object->shadow;
+ } else {
+ object = io_upl->map_object;
+ }
- offset += PAGE_SIZE;
+ /* Get the dev vnode ptr for this object */
+ if(!object || !object->pager ||
+ vnode_pager_get_object_devvp(object->pager, (uintptr_t *)&devvp) != KERN_SUCCESS) {
+ upl_unlock(upl);
+ goto out;
}
- vm_object_unlock(object);
- if (range) {
- if (offset > offset_end)
- offset = offset_end;
- if(offset > offset_beg) {
- *range = (uint32_t) (offset - offset_beg);
- assert(*range == (offset - offset_beg));
+ upl_unlock(upl);
+
+ /* Now we have all the information needed to do the expedite */
+
+ offset = 0;
+ while (offset < io_upl_size) {
+ blkno = io_upl_reprio_info[(offset / PAGE_SIZE)] & UPL_REPRIO_INFO_MASK;
+ len = (io_upl_reprio_info[(offset / PAGE_SIZE)] >> UPL_REPRIO_INFO_SHIFT) & UPL_REPRIO_INFO_MASK;
+
+ /*
+ * This implementation may cause some spurious expedites due to the
+ * fact that we dont cleanup the blkno & len from the upl_reprio_info
+ * even after the I/O is complete.
+ */
+
+ if (blkno != 0 && len != 0) {
+ /* Create the request for I/O reprioritization */
+ req = (io_reprioritize_req_t)zalloc(io_reprioritize_req_zone);
+ assert(req != NULL);
+ req->blkno = blkno;
+ req->len = len;
+ req->priority = prio;
+ req->devvp = devvp;
+
+ /* Insert request into the reprioritization list */
+ IO_REPRIORITIZE_LIST_LOCK();
+ queue_enter(&io_reprioritize_list, req, io_reprioritize_req_t, io_reprioritize_list);
+ IO_REPRIORITIZE_LIST_UNLOCK();
+
+ offset += len;
} else {
- *range = 0;
+ offset += PAGE_SIZE;
}
}
- return KERN_SUCCESS;
-}
+ /* Wakeup reprioritize thread */
+ IO_REPRIO_THREAD_WAKEUP();
-uint32_t scan_object_collision = 0;
+out:
+ kfree(io_upl_reprio_info, sizeof(uint64_t) * (io_upl_size / PAGE_SIZE));
+ return;
+}
void
-vm_object_lock(vm_object_t object)
+vm_page_handle_prio_inversion(vm_object_t o, vm_page_t m)
{
- if (object == vm_pageout_scan_wants_object) {
- scan_object_collision++;
- mutex_pause(2);
- }
- lck_rw_lock_exclusive(&object->Lock);
-}
+ upl_t upl;
+ upl_page_info_t *pl;
+ unsigned int i, num_pages;
+ int cur_tier;
-boolean_t
-vm_object_lock_avoid(vm_object_t object)
-{
- if (object == vm_pageout_scan_wants_object) {
- scan_object_collision++;
- return TRUE;
+ cur_tier = proc_get_effective_thread_policy(current_thread(), TASK_POLICY_IO);
+
+ /*
+ Scan through all UPLs associated with the object to find the
+ UPL containing the contended page.
+ */
+ queue_iterate(&o->uplq, upl, upl_t, uplq) {
+ if (((upl->flags & UPL_EXPEDITE_SUPPORTED) == 0) || upl->upl_priority <= cur_tier)
+ continue;
+ pl = UPL_GET_INTERNAL_PAGE_LIST(upl);
+ num_pages = (upl->size / PAGE_SIZE);
+
+ /*
+ For each page in the UPL page list, see if it matches the contended
+ page and was issued as a low prio I/O.
+ */
+ for(i=0; i < num_pages; i++) {
+ if(UPL_PAGE_PRESENT(pl,i) && VM_PAGE_GET_PHYS_PAGE(m) == pl[i].phys_addr) {
+ if ((upl->flags & UPL_DECMP_REQ) && upl->decmp_io_upl) {
+ KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_VM, VM_PAGE_EXPEDITE)) | DBG_FUNC_NONE, VM_KERNEL_UNSLIDE_OR_PERM(upl->upl_creator), VM_KERNEL_UNSLIDE_OR_PERM(m),
+ VM_KERNEL_UNSLIDE_OR_PERM(upl), upl->upl_priority, 0);
+ vm_decmp_upl_reprioritize(upl, cur_tier);
+ break;
+ }
+ KERNEL_DEBUG_CONSTANT((MACHDBG_CODE(DBG_MACH_VM, VM_PAGE_EXPEDITE)) | DBG_FUNC_NONE, VM_KERNEL_UNSLIDE_OR_PERM(upl->upl_creator), VM_KERNEL_UNSLIDE_OR_PERM(m),
+ upl->upl_reprio_info[i], upl->upl_priority, 0);
+ if (UPL_REPRIO_INFO_BLKNO(upl, i) != 0 && UPL_REPRIO_INFO_LEN(upl, i) != 0)
+ vm_page_request_reprioritize(o, UPL_REPRIO_INFO_BLKNO(upl, i), UPL_REPRIO_INFO_LEN(upl, i), cur_tier);
+ break;
+ }
+ }
+ /* Check if we found any hits */
+ if (i != num_pages)
+ break;
}
- return FALSE;
-}
+
+ return;
+}
-boolean_t
-_vm_object_lock_try(vm_object_t object)
+wait_result_t
+vm_page_sleep(vm_object_t o, vm_page_t m, int interruptible)
{
- return (lck_rw_try_lock_exclusive(&object->Lock));
-}
+ wait_result_t ret;
-boolean_t
-vm_object_lock_try(vm_object_t object)
-{
- if (vm_object_lock_avoid(object)) {
- mutex_pause(2);
- }
- return _vm_object_lock_try(object);
-}
-void
-vm_object_lock_shared(vm_object_t object)
-{
- if (vm_object_lock_avoid(object)) {
- mutex_pause(2);
- }
- lck_rw_lock_shared(&object->Lock);
+ KERNEL_DEBUG((MACHDBG_CODE(DBG_MACH_VM, VM_PAGE_SLEEP)) | DBG_FUNC_START, o, m, 0, 0, 0);
+
+ if (o->io_tracking && ((m->busy == TRUE) || (m->cleaning == TRUE) || VM_PAGE_WIRED(m))) {
+ /*
+ Indicates page is busy due to an I/O. Issue a reprioritize request if necessary.
+ */
+ vm_page_handle_prio_inversion(o,m);
+ }
+ m->wanted = TRUE;
+ ret = thread_sleep_vm_object(o, m, interruptible);
+ KERNEL_DEBUG((MACHDBG_CODE(DBG_MACH_VM, VM_PAGE_SLEEP)) | DBG_FUNC_END, o, m, 0, 0, 0);
+ return ret;
}
-boolean_t
-vm_object_lock_try_shared(vm_object_t object)
+static void
+io_reprioritize_thread(void *param __unused, wait_result_t wr __unused)
{
- if (vm_object_lock_avoid(object)) {
- mutex_pause(2);
- }
- return (lck_rw_try_lock_shared(&object->Lock));
+ io_reprioritize_req_t req = NULL;
+
+ while(1) {
+
+ IO_REPRIORITIZE_LIST_LOCK();
+ if (queue_empty(&io_reprioritize_list)) {
+ IO_REPRIORITIZE_LIST_UNLOCK();
+ break;
+ }
+
+ queue_remove_first(&io_reprioritize_list, req, io_reprioritize_req_t, io_reprioritize_list);
+ IO_REPRIORITIZE_LIST_UNLOCK();
+
+ vnode_pager_issue_reprioritize_io(req->devvp, req->blkno, req->len, req->priority);
+ zfree(io_reprioritize_req_zone, req);
+ }
+
+ IO_REPRIO_THREAD_CONTINUATION();
}
+#endif
projects / apple / xnu.git / blobdiff