X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/935ed37a5c468c8a1c07408573c08b8b7ef80e8b..d190cdc3f5544636abb56dc1874be391d3e1b148:/osfmk/vm/vm_object.c diff --git a/osfmk/vm/vm_object.c b/osfmk/vm/vm_object.c index 680c07f12..72b525fdd 100644 --- a/osfmk/vm/vm_object.c +++ b/osfmk/vm/vm_object.c @@ -72,21 +72,25 @@ #include #include +#include + #include #include #include #include -#include #include #include +#include #include #include #include #include #include +#include #include +#include #include #include #include @@ -95,6 +99,40 @@ #include #include +#include + +#if CONFIG_PHANTOM_CACHE +#include +#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 @@ -175,12 +213,6 @@ static kern_return_t vm_object_terminate( extern void vm_object_remove( vm_object_t object); -static vm_object_t vm_object_cache_trim( - boolean_t called_from_vm_object_deallocate); - -static void vm_object_deactivate_all_pages( - vm_object_t object); - static kern_return_t vm_object_copy_call( vm_object_t src_object, vm_object_offset_t src_offset, @@ -196,7 +228,8 @@ static void vm_object_do_bypass( vm_object_t backing_object); static void vm_object_release_pager( - memory_object_t pager); + memory_object_t pager, + boolean_t hashed); static zone_t vm_object_zone; /* vm backing store zone */ @@ -204,9 +237,11 @@ static zone_t vm_object_zone; /* vm backing store zone */ * 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 @@ -214,7 +249,7 @@ vm_object_t kernel_object; * 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 @@ -226,6 +261,11 @@ static struct vm_object vm_submap_object_store; */ static struct vm_object vm_object_template; +unsigned int vm_page_purged_wired = 0; +unsigned int vm_page_purged_busy = 0; +unsigned int vm_page_purged_others = 0; + +#if VM_OBJECT_CACHE /* * Virtual memory objects that are not referenced by * any address maps, but that are allowed to persist @@ -254,23 +294,53 @@ static struct vm_object vm_object_template; * from the reference mechanism, so that the lock need * not be held to make simple references. */ -static queue_head_t vm_object_cached_list; -static int vm_object_cached_count=0; +static vm_object_t vm_object_cache_trim( + boolean_t called_from_vm_object_deallocate); + +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 decl_mutex_data(,vm_object_cached_lock_data) - #define vm_object_cache_lock() \ - mutex_lock(&vm_object_cached_lock_data) -#define vm_object_cache_lock_try() \ - mutex_try(&vm_object_cached_lock_data) + 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() \ - mutex_unlock(&vm_object_cached_lock_data) + lck_mtx_unlock(&vm_object_cached_lock_data) + +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_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; +static struct zone *vm_object_hash_zone; struct vm_object_hash_entry { queue_chain_t hash_link; /* hash chain link */ @@ -283,9 +353,12 @@ struct vm_object_hash_entry { typedef struct vm_object_hash_entry *vm_object_hash_entry_t; #define VM_OBJECT_HASH_ENTRY_NULL ((vm_object_hash_entry_t) 0) -#define VM_OBJECT_HASH_SHIFT 8 +#define VM_OBJECT_HASH_SHIFT 5 #define vm_object_hash(pager) \ - ((((unsigned)pager) >> VM_OBJECT_HASH_SHIFT) % VM_OBJECT_HASH_COUNT) + ((int)((((uintptr_t)pager) >> VM_OBJECT_HASH_SHIFT) % VM_OBJECT_HASH_COUNT)) + +#define vm_object_lock_hash(pager) \ + ((int)((((uintptr_t)pager) >> VM_OBJECT_HASH_SHIFT) % VM_OBJECT_HASH_LOCK_COUNT)) void vm_object_hash_entry_free( vm_object_hash_entry_t entry); @@ -293,38 +366,101 @@ void vm_object_hash_entry_free( static void vm_object_reap(vm_object_t object); static void vm_object_reap_async(vm_object_t object); static void vm_object_reaper_thread(void); -static queue_head_t vm_object_reaper_queue; /* protected by vm_object_cache_lock() */ + +static lck_mtx_t vm_object_reaper_lock_data; +static lck_mtx_ext_t vm_object_reaper_lock_data_ext; + +static queue_head_t vm_object_reaper_queue; /* protected by vm_object_reaper_lock() */ unsigned int vm_object_reap_count = 0; unsigned int vm_object_reap_count_async = 0; +#define vm_object_reaper_lock() \ + lck_mtx_lock(&vm_object_reaper_lock_data) +#define vm_object_reaper_lock_spin() \ + lck_mtx_lock_spin(&vm_object_reaper_lock_data) +#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 * +vm_object_hash_lock_spin( + memory_object_t pager) +{ + int index; + + index = vm_object_lock_hash(pager); + + lck_mtx_lock_spin(&vm_object_hashed_lock_data[index]); + + return (&vm_object_hashed_lock_data[index]); +} + +static void +vm_object_hash_unlock(lck_mtx_t *lck) +{ + lck_mtx_unlock(lck); +} + + /* * vm_object_hash_lookup looks up a pager in the hashtable * and returns the corresponding entry, with optional removal. */ - static vm_object_hash_entry_t vm_object_hash_lookup( memory_object_t pager, boolean_t remove_entry) { - register queue_t bucket; - register vm_object_hash_entry_t entry; + queue_t bucket; + vm_object_hash_entry_t entry; bucket = &vm_object_hashtable[vm_object_hash(pager)]; entry = (vm_object_hash_entry_t)queue_first(bucket); while (!queue_end(bucket, (queue_entry_t)entry)) { - if (entry->pager == pager && !remove_entry) - return(entry); - else if (entry->pager == pager) { - queue_remove(bucket, entry, - vm_object_hash_entry_t, hash_link); + if (entry->pager == pager) { + if (remove_entry) { + queue_remove(bucket, entry, + vm_object_hash_entry_t, hash_link); + } return(entry); } - entry = (vm_object_hash_entry_t)queue_next(&entry->hash_link); } - return(VM_OBJECT_HASH_ENTRY_NULL); } @@ -335,13 +471,31 @@ vm_object_hash_lookup( static void vm_object_hash_insert( - vm_object_hash_entry_t entry) + vm_object_hash_entry_t entry, + vm_object_t object) { - register queue_t bucket; + 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; } static vm_object_hash_entry_t @@ -378,23 +532,37 @@ _vm_object_allocate( { XPR(XPR_VM_OBJECT, "vm_object_allocate, object 0x%X size 0x%X\n", - (integer_t)object, size, 0,0,0); + object, size, 0,0,0); *object = vm_object_template; - queue_init(&object->memq); + vm_page_queue_init(&object->memq); queue_init(&object->msr_q); -#ifdef 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); @@ -407,10 +575,12 @@ vm_object_allocate( } -lck_grp_t vm_object_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_grp_t vm_object_lck_grp; +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: @@ -420,60 +590,95 @@ lck_attr_t kernel_object_lck_attr; __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_32(512*1024), - round_page_32(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(); - queue_init(&vm_object_reaper_queue); queue_init(&vm_object_cached_list); - mutex_init(&vm_object_cached_lock_data, 0); + + lck_mtx_init_ext(&vm_object_cached_lock_data, + &vm_object_cached_lock_data_ext, + &vm_object_cache_lck_grp, + &vm_object_lck_attr); + + queue_init(&vm_object_reaper_queue); + + for (i = 0; i < VM_OBJECT_HASH_LOCK_COUNT; i++) { + lck_mtx_init_ext(&vm_object_hashed_lock_data[i], + &vm_object_hashed_lock_data_ext[i], + &vm_object_lck_grp, + &vm_object_lck_attr); + } + lck_mtx_init_ext(&vm_object_reaper_lock_data, + &vm_object_reaper_lock_data_ext, + &vm_object_lck_grp, + &vm_object_lck_attr); vm_object_hash_zone = zinit((vm_size_t) sizeof (struct vm_object_hash_entry), - round_page_32(512*1024), - round_page_32(12*1024), + 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]); - vm_object_init_lck_grp(); /* * Fill in a template object, for quick initialization */ /* 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 * allocate some memory and VM is not fully initialized yet. - * The lock will be initialized for each allocate object in + * The lock will be initialized for each allocated object in * _vm_object_allocate(), so we don't need to initialize it in * the vm_object_template. */ 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.res_count = 1; #endif /* TASK_SWAPPER */ vm_object_template.resident_page_count = 0; + vm_object_template.wired_page_count = 0; + 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.all_wanted = 0; /* all bits FALSE */ @@ -488,8 +693,8 @@ vm_object_bootstrap(void) 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; @@ -508,20 +713,30 @@ vm_object_bootstrap(void) 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.not_in_use = 0; -#ifdef UPL_DEBUG + 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 CONFIG_IOSCHED || UPL_DEBUG vm_object_template.uplq.prev = NULL; vm_object_template.uplq.next = NULL; #endif /* UPL_DEBUG */ @@ -530,10 +745,33 @@ vm_object_bootstrap(void) 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" */ @@ -545,14 +783,13 @@ vm_object_bootstrap(void) * VM_MAX_KERNEL_ADDRESS (vm_last_addr) is a maximum address, not a size. */ -#ifdef ppc - _vm_object_allocate((vm_last_addr - VM_MIN_KERNEL_ADDRESS) + 1, - kernel_object); -#else - _vm_object_allocate((VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) + 1, - kernel_object); -#endif + _vm_object_allocate(VM_MAX_KERNEL_ADDRESS + 1, + kernel_object); + + _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 @@ -560,13 +797,8 @@ vm_object_bootstrap(void) */ vm_submap_object = &vm_submap_object_store; -#ifdef ppc - _vm_object_allocate((vm_last_addr - VM_MIN_KERNEL_ADDRESS) + 1, - vm_submap_object); -#else - _vm_object_allocate((VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) + 1, - vm_submap_object); -#endif + _vm_object_allocate(VM_MAX_KERNEL_ADDRESS + 1, + vm_submap_object); vm_submap_object->copy_strategy = MEMORY_OBJECT_COPY_NONE; /* @@ -575,11 +807,31 @@ vm_object_bootstrap(void) * 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) @@ -610,21 +862,25 @@ vm_object_init(void) __private_extern__ void vm_object_init_lck_grp(void) { - /* + /* * initialze the vm_object lock world */ - lck_grp_attr_setdefault(&vm_object_lck_grp_attr); + 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 #define MIGHT_NOT_CACHE_SHADOWS 1 #if MIGHT_NOT_CACHE_SHADOWS static int cache_shadows = TRUE; #endif /* MIGHT_NOT_CACHE_SHADOWS */ +#endif /* * vm_object_deallocate: @@ -640,13 +896,16 @@ static int cache_shadows = TRUE; 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; - vm_object_t shadow = VM_OBJECT_NULL; uint32_t try_failed_count = 0; +#endif + vm_object_t shadow = VM_OBJECT_NULL; // if(object)dbgLog(object, object->ref_count, object->can_persist, 3); /* (TEST/DEBUG) */ // else dbgLog(object, 0, 0, 3); /* (TEST/DEBUG) */ @@ -654,18 +913,38 @@ vm_object_deallocate( if (object == VM_OBJECT_NULL) return; - if (object == kernel_object) { - vm_object_lock(kernel_object); - kernel_object->ref_count--; - if (kernel_object->ref_count == 0) { - panic("vm_object_deallocate: losing kernel_object\n"); + if (object == kernel_object || object == compressor_object) { + vm_object_lock_shared(object); + + OSAddAtomic(-1, &object->ref_count); + + if (object->ref_count == 0) { + if (object == kernel_object) + panic("vm_object_deallocate: losing kernel_object\n"); + else + panic("vm_object_deallocate: losing compressor_object\n"); } - vm_object_unlock(kernel_object); + 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; @@ -686,23 +965,36 @@ vm_object_deallocate( * 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) { - /* ref_count was updated atomically ! */ + /* + * ref_count was updated atomically ! + */ vm_object_deallocate_shared_successes++; return; } @@ -717,28 +1009,8 @@ vm_object_deallocate( while (object != VM_OBJECT_NULL) { - /* - * The cache holds a reference (uncounted) to - * the object; we must lock it before removing - * the object. - */ - for (;;) { - vm_object_cache_lock(); - - /* - * if we try to take a regular lock here - * we risk deadlocking against someone - * holding a lock on this object while - * trying to vm_object_deallocate a different - * object - */ - if (vm_object_lock_try(object)) - break; - vm_object_cache_unlock(); - try_failed_count++; + vm_object_lock(object); - mutex_pause(try_failed_count); /* wait a bit */ - } assert(object->ref_count > 0); /* @@ -753,31 +1025,16 @@ vm_object_deallocate( /* more mappers for this object */ if (pager != MEMORY_OBJECT_NULL) { + vm_object_mapping_wait(object, THREAD_UNINT); + vm_object_mapping_begin(object); vm_object_unlock(object); - vm_object_cache_unlock(); - - memory_object_unmap(pager); - - try_failed_count = 0; - for (;;) { - vm_object_cache_lock(); - /* - * if we try to take a regular lock here - * we risk deadlocking against someone - * holding a lock on this object while - * trying to vm_object_deallocate a different - * object - */ - if (vm_object_lock_try(object)) - break; - vm_object_cache_unlock(); - try_failed_count++; + memory_object_last_unmap(pager); - mutex_pause(try_failed_count); /* wait a bit */ - } - assert(object->ref_count > 0); + vm_object_lock(object); + vm_object_mapping_end(object); } + assert(object->ref_count > 0); } /* @@ -796,7 +1053,6 @@ vm_object_deallocate( vm_object_lock_assert_exclusive(object); object->ref_count--; vm_object_res_deallocate(object); - vm_object_cache_unlock(); if (object->ref_count == 1 && object->shadow != VM_OBJECT_NULL) { @@ -818,13 +1074,14 @@ vm_object_deallocate( */ vm_object_collapse(object, 0, FALSE); } - vm_object_unlock(object); +#if VM_OBJECT_CACHE if (retry_cache_trim && ((object = vm_object_cache_trim(TRUE)) != VM_OBJECT_NULL)) { continue; } +#endif return; } @@ -839,11 +1096,12 @@ vm_object_deallocate( VM_OBJECT_EVENT_INITIALIZED, THREAD_UNINT); vm_object_unlock(object); - vm_object_cache_unlock(); + thread_block(THREAD_CONTINUE_NULL); continue; } +#if VM_OBJECT_CACHE /* * If this object can persist, then enter it in * the cache. Otherwise, terminate it. @@ -859,11 +1117,12 @@ vm_object_deallocate( * Now it is safe to decrement reference count, * and to return if reference count is > 0. */ + vm_object_lock_assert_exclusive(object); if (--object->ref_count > 0) { vm_object_res_deallocate(object); vm_object_unlock(object); - vm_object_cache_unlock(); + if (retry_cache_trim && ((object = vm_object_cache_trim(TRUE)) != VM_OBJECT_NULL)) { @@ -892,16 +1151,38 @@ vm_object_deallocate( VM_OBJ_RES_DECR(object); XPR(XPR_VM_OBJECT, "vm_o_deallocate: adding %x to cache, queue = (%x, %x)\n", - (integer_t)object, - (integer_t)vm_object_cached_list.next, - (integer_t)vm_object_cached_list.prev,0,0); + object, + vm_object_cached_list.next, + vm_object_cached_list.prev,0,0); + + vm_object_unlock(object); + + try_failed_count = 0; + for (;;) { + vm_object_cache_lock(); + + /* + * if we try to take a regular lock here + * we risk deadlocking against someone + * holding a lock on this object while + * trying to vm_object_deallocate a different + * object + */ + if (vm_object_lock_try(object)) + break; + vm_object_cache_unlock(); + try_failed_count++; + + mutex_pause(try_failed_count); /* wait a bit */ + } vm_object_cached_count++; if (vm_object_cached_count > vm_object_cached_high) vm_object_cached_high = vm_object_cached_count; queue_enter(&vm_object_cached_list, object, vm_object_t, cached_list); vm_object_cache_unlock(); + vm_object_deactivate_all_pages(object); vm_object_unlock(object); @@ -931,14 +1212,15 @@ vm_object_deallocate( return; } retry_cache_trim = TRUE; - - } else { + } else +#endif /* VM_OBJECT_CACHE */ + { /* * This object is not cachable; terminate it. */ XPR(XPR_VM_OBJECT, "vm_o_deallocate: !cacheable 0x%X res %d paging_ops %d thread 0x%p ref %d\n", - (integer_t)object, object->resident_page_count, + object, object->resident_page_count, object->paging_in_progress, (void *)current_thread(),object->ref_count); @@ -952,5506 +1234,7595 @@ vm_object_deallocate( * a normal reference. */ shadow = object->pageout?VM_OBJECT_NULL:object->shadow; - if(vm_object_terminate(object) != KERN_SUCCESS) { + + if (vm_object_terminate(object) != KERN_SUCCESS) { return; } if (shadow != VM_OBJECT_NULL) { object = shadow; continue; } +#if VM_OBJECT_CACHE if (retry_cache_trim && ((object = vm_object_cache_trim(TRUE)) != VM_OBJECT_NULL)) { continue; } +#endif return; } } +#if VM_OBJECT_CACHE assert(! retry_cache_trim); +#endif } -/* - * 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. - */ + 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", - (integer_t)vm_object_cached_list.next, - (integer_t)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; - /* - * 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; - if(vm_object_terminate(object) != KERN_SUCCESS) - continue; - if (shadow != VM_OBJECT_NULL) { - if (called_from_vm_object_deallocate) { - return shadow; - } else { - vm_object_deallocate(shadow); - } - } - } -} + vm_object_page_grab_pmapped++; -#define VM_OBJ_TERM_STATS DEBUG -#if VM_OBJ_TERM_STATS -uint32_t vm_object_terminate_pages_freed = 0; -uint32_t vm_object_terminate_pages_removed = 0; -uint32_t vm_object_terminate_batches = 0; -uint32_t vm_object_terminate_biggest_batch = 0; -#endif /* VM_OBJ_TERM_STATS */ + if (p->reference == FALSE || p->dirty == FALSE) { -#define V_O_T_MAX_BATCH 256 + refmod_state = pmap_get_refmod(VM_PAGE_GET_PHYS_PAGE(p)); -/* - * 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( - register vm_object_t object) -{ - register vm_page_t p; - vm_object_t shadow_object; - vm_page_t local_free_q; - int loop_count; -#if VM_OBJ_TERM_STATS - uint32_t local_free_count; - uint32_t pages_removed; -#endif /* VM_OBJ_TERM_STATS */ + 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) { -#if VM_OBJ_TERM_STATS -#define VM_OBJ_TERM_FREELIST_DEBUG(_pages_removed, _local_free_count) \ - MACRO_BEGIN \ - if (_pages_removed) { \ - hw_atomic_add(&vm_object_terminate_batches, 1); \ - hw_atomic_add(&vm_object_terminate_pages_removed, \ - _pages_removed); \ - hw_atomic_add(&vm_object_terminate_pages_freed, \ - _local_free_count); \ - if (_local_free_count > \ - vm_object_terminate_biggest_batch) { \ - vm_object_terminate_biggest_batch = \ - _local_free_count; \ - } \ - _local_free_count = 0; \ - } \ - MACRO_END -#else /* VM_OBJ_TERM_STATS */ -#define VM_OBJ_TERM_FREELIST_DEBUG(_pages_removed, _local_free_count) -#endif /* VM_OBJ_TERM_STATS */ + refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p)); -#define VM_OBJ_TERM_FREELIST(_pages_removed, _local_free_count, _local_free_q) \ - MACRO_BEGIN \ - VM_OBJ_TERM_FREELIST_DEBUG(_pages_removed, _local_free_count); \ - if (_local_free_q) { \ - vm_page_free_list(_local_free_q); \ - _local_free_q = VM_PAGE_NULL; \ - } \ - MACRO_END + 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); - XPR(XPR_VM_OBJECT, "vm_object_terminate, object 0x%X ref %d\n", - (integer_t)object, object->ref_count, 0, 0, 0); - - local_free_q = VM_PAGE_NULL; -#if VM_OBJ_TERM_STATS - local_free_count = 0; - pages_removed = 0; -#endif /* VM_OBJ_TERM_STATS */ - - if (!object->pageout && (!object->temporary || object->can_persist) - && (object->pager != NULL || object->shadow_severed)) { - vm_object_cache_unlock(); - loop_count = V_O_T_MAX_BATCH; - vm_page_lock_queues(); - while (!queue_empty(&object->memq)) { - if (--loop_count == 0) { - /* - * Free the pages we've reclaimed so far and - * take a little break to avoid hogging - * the page queues lock too long. - */ - VM_OBJ_TERM_FREELIST(pages_removed, - local_free_count, - local_free_q); - mutex_yield(&vm_page_queue_lock); - loop_count = V_O_T_MAX_BATCH; + p_skipped++; + continue; } - /* - * 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_page_lockspin_queues(); +take_page: + vm_page_free_prepare_queues(p); + vm_object_page_grab_returned++; + vm_object_page_grab_skipped += p_skipped; - p = (vm_page_t) queue_first(&object->memq); + vm_page_unlock_queues(); - VM_PAGE_CHECK(p); + vm_page_free_prepare_object(p, TRUE); + + return (p); + } + vm_object_page_grab_skipped += p_skipped; + vm_object_page_grab_failed++; - if (p->busy || p->cleaning) { - if(p->cleaning || p->absent) { - /* free the pages reclaimed so far */ - VM_OBJ_TERM_FREELIST(pages_removed, - local_free_count, - local_free_q); - vm_page_unlock_queues(); - vm_object_paging_wait(object, THREAD_UNINT); - vm_page_lock_queues(); - continue; - } else { - panic("vm_object_terminate.3 %p %p", object, p); - } - } + return (NULL); +} - p->busy = TRUE; - VM_PAGE_QUEUES_REMOVE(p); -#if VM_OBJ_TERM_STATS - pages_removed++; -#endif /* VM_OBJ_TERM_STATS */ - 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. - */ +#define EVICT_PREPARE_LIMIT 64 +#define EVICT_AGE 10 - goto free_page; - } +static clock_sec_t vm_object_cache_aging_ts = 0; - if (p->fictitious) { - if (p->phys_page == vm_page_guard_addr) { - goto free_page; - } - panic("vm_object_terminate.4 %p %p", object, p); - } +static void +vm_object_cache_remove_locked( + vm_object_t object) +{ + assert(object->purgable == VM_PURGABLE_DENY); + assert(object->wired_page_count == 0); - if (!p->dirty && p->wpmapped) - p->dirty = pmap_is_modified(p->phys_page); + queue_remove(&vm_object_cached_list, object, vm_object_t, objq); + object->objq.next = NULL; + object->objq.prev = NULL; - if ((p->dirty || p->precious) && !p->error && object->alive) { - /* free the pages reclaimed so far */ - VM_OBJ_TERM_FREELIST(pages_removed, - local_free_count, - local_free_q); - vm_page_unlock_queues(); - vm_pageout_cluster(p); /* flush page */ - vm_object_paging_wait(object, THREAD_UNINT); - XPR(XPR_VM_OBJECT, - "vm_object_terminate restart, object 0x%X ref %d\n", - (integer_t)object, object->ref_count, 0, 0, 0); - vm_page_lock_queues(); - } else { - free_page: - /* - * Add this page to our list of reclaimed pages, - * to be freed later. - */ - vm_page_free_prepare(p); - p->pageq.next = (queue_entry_t) local_free_q; - local_free_q = p; -#if VM_OBJ_TERM_STATS - local_free_count++; -#endif /* VM_OBJ_TERM_STATS */ - } - } - - /* - * Free the remaining reclaimed pages. - */ - VM_OBJ_TERM_FREELIST(pages_removed, - local_free_count, - local_free_q); - vm_page_unlock_queues(); - vm_object_unlock(object); - vm_object_cache_lock(); - vm_object_lock(object); + vm_object_cached_count--; +} + +void +vm_object_cache_remove( + vm_object_t object) +{ + vm_object_cache_lock_spin(); + + if (object->objq.next || object->objq.prev) + vm_object_cache_remove_locked(object); + + vm_object_cache_unlock(); +} + +void +vm_object_cache_add( + vm_object_t object) +{ + clock_sec_t sec; + clock_nsec_t nsec; + + assert(object->purgable == VM_PURGABLE_DENY); + assert(object->wired_page_count == 0); + + 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); /* - * Make sure the object isn't already being terminated + * do a couple of quick checks to see if it's + * worthwhile grabbing the lock */ - if(object->terminating) { - vm_object_lock_assert_exclusive(object); - object->ref_count--; - assert(object->ref_count > 0); - vm_object_cache_unlock(); - vm_object_unlock(object); - return KERN_FAILURE; + 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); /* - * Did somebody get a reference to the object while we were - * cleaning it? + * the object on the head of the queue has not + * yet sufficiently aged */ - 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_cache_unlock(); - vm_object_unlock(object); - return KERN_FAILURE; + if (sec < vm_object_cache_aging_ts) { + KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, 0, 0, 0, 0, 0); + return (0); } - /* - * Make sure no one can look us up now. + * don't need the queue lock to find + * and lock an object on the cached list */ + vm_page_unlock_queues(); - object->terminating = TRUE; - object->alive = FALSE; - vm_object_remove(object); + vm_object_cache_lock_spin(); - /* - * 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); - } + for (;;) { + next_obj = (vm_object_t)queue_first(&vm_object_cached_list); - if (object->paging_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); + while (!queue_end(&vm_object_cached_list, (queue_entry_t)next_obj) && object_cnt++ < max_objects_to_examine) { + + object = next_obj; + next_obj = (vm_object_t)queue_next(&next_obj->objq); + + 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); + + 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 = 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(); - vm_object_unlock(object); + + if (object == VM_OBJECT_NULL) + break; + /* - * 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. + * object is locked at this point and + * has resident pages */ - return KERN_FAILURE; - } + next_p = (vm_page_t)vm_page_queue_first(&object->memq); - /* complete the VM object termination */ - vm_object_reap(object); - object = VM_OBJECT_NULL; - /* cache lock and object lock were released by vm_object_reap() */ + /* + * 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; - /* - * 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; -} + while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next_p) && object->vo_cache_pages_to_scan && ep_count < ep_limit) { -/* - * 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 cache and the VM object must be locked by caller. - * The locks 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; - vm_page_t p; - vm_page_t local_free_q; - int loop_count; -#if VM_OBJ_TERM_STATS - uint32_t local_free_count; -#endif /* VM_OBJ_TERM_STATS */ + p = next_p; + next_p = (vm_page_t)vm_page_queue_next(&next_p->listq); -#if DEBUG - mutex_assert(&vm_object_cached_lock_data, MA_OWNED); -#endif /* DEBUG */ - vm_object_lock_assert_exclusive(object); - assert(object->paging_in_progress == 0); + object->vo_cache_pages_to_scan--; - vm_object_reap_count++; + 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); - local_free_q = VM_PAGE_NULL; -#if VM_OBJ_TERM_STATS - local_free_count = 0; -#endif /* VM_OBJ_TERM_STATS */ + 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); - pager = object->pager; - object->pager = MEMORY_OBJECT_NULL; + 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); - if (pager != MEMORY_OBJECT_NULL) - memory_object_control_disable(object->pager_control); - vm_object_cache_unlock(); + vm_page_lockspin_queues(); - vm_object_lock_assert_exclusive(object); - object->ref_count--; -#if TASK_SWAPPER - assert(object->res_count == 0); -#endif /* TASK_SWAPPER */ + for (ep_index = 0; ep_index < ep_count; ep_index++) { - assert (object->ref_count == 0); + p = ep_array[ep_index]; - /* 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); + if (p->wpmapped || p->dirty || p->precious) { + p->reference = FALSE; + p->no_cache = FALSE; - /* 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); + /* + * 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); - vm_pageout_object_terminate(object); + ep_moved++; + } else { +#if CONFIG_PHANTOM_CACHE + vm_phantom_cache_add_ghost(p); +#endif + vm_page_free_prepare_queues(p); - } else if ((object->temporary && !object->can_persist) || - (pager == MEMORY_OBJECT_NULL)) { - loop_count = V_O_T_MAX_BATCH; - vm_page_lock_queues(); - while (!queue_empty(&object->memq)) { - if (--loop_count == 0) { + assert(p->pageq.next == 0 && p->pageq.prev == 0); /* - * Free the pages we reclaimed so far - * and take a little break to avoid - * hogging the page queue lock too long + * Add this page to our list of reclaimed pages, + * to be freed later. */ - VM_OBJ_TERM_FREELIST(local_free_count, - local_free_count, - local_free_q); - mutex_yield(&vm_page_queue_lock); - loop_count = V_O_T_MAX_BATCH; + p->snext = local_free_q; + local_free_q = p; + + ep_freed++; } - p = (vm_page_t) queue_first(&object->memq); + } + vm_page_unlock_queues(); + + KERNEL_DEBUG(0x13001f4 | DBG_FUNC_END, object, object->resident_page_count, ep_freed, ep_moved, 0); - vm_page_free_prepare(p); + 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); - assert(p->pageq.next == NULL && p->pageq.prev == NULL); - p->pageq.next = (queue_entry_t) local_free_q; - local_free_q = p; -#if VM_OBJ_TERM_STATS - local_free_count++; -#endif /* VM_OBJ_TERM_STATS */ + KERNEL_DEBUG(0x13001fc, object, object->resident_page_count, ep_freed, ep_moved, 0); } /* - * Free the remaining reclaimed pages + * done with this object */ - VM_OBJ_TERM_FREELIST(local_free_count, - local_free_count, - local_free_q); - vm_page_unlock_queues(); - } else if (!queue_empty(&object->memq)) { - panic("vm_object_reap: queue just emptied isn't"); - } - - assert(object->paging_in_progress == 0); - assert(object->ref_count == 0); - - /* - * 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); - vm_object_lock(object); - } - - /* kick off anyone waiting on terminating */ - object->terminating = FALSE; - vm_object_paging_begin(object); - vm_object_paging_end(object); - vm_object_unlock(object); - -#if MACH_PAGEMAP - vm_external_destroy(object->existence_map, object->size); -#endif /* MACH_PAGEMAP */ - - object->shadow = VM_OBJECT_NULL; + object = VM_OBJECT_NULL; - vm_object_lock_destroy(object); + /* + * at this point, we are not holding any locks + */ + 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(); + } /* - * Free the space for the object. + * put the page queues lock back to the caller's + * idea of it */ - zfree(vm_object_zone, object); - object = VM_OBJECT_NULL; -} - -void -vm_object_reap_async( - vm_object_t object) -{ -#if DEBUG - mutex_assert(&vm_object_cached_lock_data, MA_OWNED); -#endif /* DEBUG */ - vm_object_lock_assert_exclusive(object); + vm_page_lock_queues(); - vm_object_reap_count_async++; + vm_object_cache_pages_freed += ep_freed; + vm_object_cache_pages_moved += ep_moved; + vm_object_cache_pages_skipped += ep_skipped; - /* enqueue the VM object... */ - queue_enter(&vm_object_reaper_queue, object, - vm_object_t, cached_list); - /* ... and wake up the reaper thread */ - thread_wakeup((event_t) &vm_object_reaper_queue); + KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, ep_freed, 0, 0, 0, 0); + return (ep_freed); } -void -vm_object_reaper_thread(void) + +#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, shadow_object; + vm_object_t object = VM_OBJECT_NULL; + vm_object_t shadow; - vm_object_cache_lock(); + for (;;) { - while (!queue_empty(&vm_object_reaper_queue)) { - queue_remove_first(&vm_object_reaper_queue, - object, - vm_object_t, - cached_list); - 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. + * If we no longer need to trim the cache, + * then we are done. */ - while (object->paging_in_progress != 0) { + if (vm_object_cached_count <= vm_object_cached_max) + return VM_OBJECT_NULL; + + vm_object_cache_lock(); + if (vm_object_cached_count <= vm_object_cached_max) { vm_object_cache_unlock(); - vm_object_wait(object, - VM_OBJECT_EVENT_PAGING_IN_PROGRESS, - THREAD_UNINT); - vm_object_cache_lock(); - vm_object_lock(object); + return VM_OBJECT_NULL; } - 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; + /* + * 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); - 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; + 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--; - vm_object_cache_lock(); - } + 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. + */ - /* wait for more work... */ - assert_wait((event_t) &vm_object_reaper_queue, THREAD_UNINT); - vm_object_cache_unlock(); - thread_block((thread_continue_t) vm_object_reaper_thread); - /*NOTREACHED*/ -} + assert(object->pager_initialized); + assert(object->ref_count == 0); + vm_object_lock_assert_exclusive(object); + object->ref_count++; -/* - * Routine: vm_object_pager_wakeup - * Purpose: Wake up anyone waiting for termination of a pager. - */ + /* + * 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; -static void -vm_object_pager_wakeup( - memory_object_t pager) -{ - vm_object_hash_entry_t entry; - boolean_t waiting = FALSE; + if(vm_object_terminate(object) != KERN_SUCCESS) + continue; - /* - * If anyone was waiting for the memory_object_terminate - * to be queued, wake them up now. - */ - vm_object_cache_lock(); - entry = vm_object_hash_lookup(pager, TRUE); - if (entry != VM_OBJECT_HASH_ENTRY_NULL) - waiting = entry->waiting; - vm_object_cache_unlock(); - if (entry != VM_OBJECT_HASH_ENTRY_NULL) { - if (waiting) - thread_wakeup((event_t) pager); - vm_object_hash_entry_free(entry); + if (shadow != VM_OBJECT_NULL) { + if (called_from_vm_object_deallocate) { + return shadow; + } else { + vm_object_deallocate(shadow); + } + } } } +#endif + /* - * 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. + * 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 void -vm_object_release_pager( - memory_object_t pager) +static kern_return_t +vm_object_terminate( + vm_object_t object) { + vm_object_t shadow_object; + + XPR(XPR_VM_OBJECT, "vm_object_terminate, object 0x%X ref %d\n", + object, object->ref_count, 0, 0, 0); + + vm_object_lock_assert_exclusive(object); + + 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_reap_pages(object, REAP_TERMINATE); + } /* - * Terminate the pager. + * Make sure the object isn't already being terminated */ - - (void) memory_object_terminate(pager); + if (object->terminating) { + vm_object_lock_assert_exclusive(object); + object->ref_count--; + assert(object->ref_count > 0); + vm_object_unlock(object); + return KERN_FAILURE; + } /* - * Wakeup anyone waiting for this terminate + * Did somebody get a reference to the object while we were + * cleaning it? */ - 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. + * Make sure no one can look us up now. */ - 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); + object->terminating = TRUE; + object->alive = FALSE; - /* - * 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.] - */ + if ( !object->internal && (object->objq.next || object->objq.prev)) + vm_object_cache_remove(object); - vm_object_cache_lock(); - vm_object_lock(object); - object->can_persist = FALSE; - object->named = FALSE; - object->alive = FALSE; + if (object->hashed) { + lck_mtx_t *lck; + lck = vm_object_hash_lock_spin(object->pager); + vm_object_remove(object); + vm_object_hash_unlock(lck); + } /* - * Rip out the pager from the vm_object now... + * 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_remove(object); - old_pager = object->pager; - object->pager = MEMORY_OBJECT_NULL; - if (old_pager != MEMORY_OBJECT_NULL) - memory_object_control_disable(object->pager_control); - vm_object_cache_unlock(); - + 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; + } /* - * Wait for the existing paging activity (that got - * through before we nulled out the pager) to subside. + * complete the VM object termination */ - - vm_object_paging_wait(object, THREAD_UNINT); - vm_object_unlock(object); + vm_object_reap(object); + object = VM_OBJECT_NULL; /* - * Terminate the object now. + * 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. */ - if (old_pager != MEMORY_OBJECT_NULL) { - vm_object_release_pager(old_pager); - - /* - * 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); - - } - return(KERN_SUCCESS); + 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_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) + +void +vm_object_reap( + 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 + memory_object_t pager; - 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 */ - mutex_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(); -} + vm_object_lock_assert_exclusive(object); + assert(object->paging_in_progress == 0); + assert(object->activity_in_progress == 0); -__private_extern__ void -vm_object_deactivate_pages( - vm_object_t object, - vm_object_offset_t offset, - vm_object_size_t size, - boolean_t kill_page) -{ - vm_object_t orig_object; - int pages_moved = 0; - int pages_found = 0; + vm_object_reap_count++; /* - * entered with object lock held, acquire a paging reference to - * prevent the memory_object and control ports from - * being destroyed. + * 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. */ - orig_object = object; - - for (;;) { - register vm_page_t m; - vm_object_offset_t toffset; - vm_object_size_t tsize; + if (object->internal && + object->purgable != VM_PURGABLE_DENY) { + vm_purgeable_accounting(object, + object->purgable, + TRUE); /* disown */ + } - vm_object_paging_begin(object); - vm_page_lock_queues(); + pager = object->pager; + object->pager = MEMORY_OBJECT_NULL; - for (tsize = size, toffset = offset; tsize; tsize -= PAGE_SIZE, toffset += PAGE_SIZE) { + if (pager != MEMORY_OBJECT_NULL) + memory_object_control_disable(object->pager_control); - if ((m = vm_page_lookup(object, toffset)) != VM_PAGE_NULL) { + object->ref_count--; +#if TASK_SWAPPER + assert(object->res_count == 0); +#endif /* TASK_SWAPPER */ - pages_found++; + assert (object->ref_count == 0); - if ((m->wire_count == 0) && (!m->private) && (!m->gobbled) && (!m->busy)) { + /* + * remove from purgeable queue if it's on + */ + if (object->internal) { + task_t owner; - assert(!m->laundry); + owner = object->vo_purgeable_owner; - m->reference = FALSE; - pmap_clear_reference(m->phys_page); + VM_OBJECT_UNWIRED(object); - if ((kill_page) && (object->internal)) { - m->precious = FALSE; - m->dirty = FALSE; - pmap_clear_modify(m->phys_page); -#if MACH_PAGEMAP - vm_external_state_clr(object->existence_map, offset); -#endif /* MACH_PAGEMAP */ - } + if (object->purgable == VM_PURGABLE_DENY) { + /* not purgeable: nothing to do */ + } else if (object->purgable == VM_PURGABLE_VOLATILE) { + purgeable_q_t queue; - if (!m->throttled) { - VM_PAGE_QUEUES_REMOVE(m); + assert(object->vo_purgeable_owner == NULL); - 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); - } + queue = vm_purgeable_object_remove(object); + assert(queue); - m->inactive = TRUE; - if (!m->fictitious) { - vm_page_inactive_count++; - token_new_pagecount++; - } else { - assert(m->phys_page == vm_page_fictitious_addr); - } + 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(); + } - pages_moved++; - } - } + /* + * 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; } - vm_page_unlock_queues(); - vm_object_paging_end(object); + 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); + } + + /* + * 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 (object->shadow) { - vm_object_t tmp_object; + vm_pageout_object_terminate(object); - kill_page = 0; + } else if (((object->temporary && !object->can_persist) || (pager == MEMORY_OBJECT_NULL))) { - offset += object->shadow_offset; + 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); - tmp_object = object->shadow; - vm_object_lock(tmp_object); + /* + * 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 (object != orig_object) - vm_object_unlock(object); - object = tmp_object; - } else - break; + /* 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; + +#if VM_OBJECT_TRACKING + if (vm_object_tracking_inited) { + btlog_remove_entries_for_element(vm_object_tracking_btlog, + object); } - if (object != orig_object) - vm_object_unlock(object); +#endif /* VM_OBJECT_TRACKING */ + + vm_object_lock_destroy(object); + /* + * Free the space for the object. + */ + zfree(vm_object_zone, object); + object = VM_OBJECT_NULL; } -/* - * 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 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__ 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); - - vm_object_lock(object); - - 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; - - 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); - - for (phys_addr = phys_start; - phys_addr < phys_end; - phys_addr += PAGE_SIZE_64) { - pmap_page_protect(phys_addr >> PAGE_SHIFT, prot); - } - } - return; - } - - 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; - } - - /* 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; - end = offset + size; +unsigned int vm_max_batch = 256; - 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 V_O_R_MAX_BATCH 128 - 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)) { +#define BATCH_LIMIT(max) (vm_max_batch >= max ? max : vm_max_batch) - pmap_page_protect(p->phys_page, prot); - } - } - } - } else { - vm_page_t p; - vm_object_offset_t end; - vm_object_offset_t target_off; - end = offset + size; +#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 = 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 - 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_offset_t start; - start = pmap_start + - (vm_offset_t)(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); - } - } - } - } - if (prot == VM_PROT_NONE) { +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; + + if (reap_type == REAP_DATA_FLUSH) { /* - * Must follow shadow chain to remove access - * to pages in shadowed objects. + * We need to disconnect pages from all pmaps before + * releasing them to the free list */ - register vm_object_t next_object; - - 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; - } - } - else { + disconnect_on_release = TRUE; + } else { /* - * Pages in shadowed objects may never have - * write permission - we may stop here. + * 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. */ - break; - } + disconnect_on_release = FALSE; } + +restart_after_sleep: + if (vm_page_queue_empty(&object->memq)) + return; + loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH); - vm_object_unlock(object); -} - -/* - * 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( - 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 (reap_type == REAP_PURGEABLE) + pmap_flush_context_init(&pmap_flush_context_storage); - 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); + vm_page_lockspin_queues(); - if (size == 0) { - vm_object_unlock(src_object); - *_result_object = VM_OBJECT_NULL; - return(KERN_INVALID_ARGUMENT); - } + next = (vm_page_t)vm_page_queue_first(&object->memq); - /* - * Prevent destruction of the source object while we copy. - */ + while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next)) { - vm_object_reference_locked(src_object); - vm_object_unlock(src_object); + p = next; + next = (vm_page_t)vm_page_queue_next(&next->listq); - /* - * 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. - */ + if (--loop_count == 0) { + + vm_page_unlock_queues(); - new_object = vm_object_allocate(size); - new_offset = 0; + if (local_free_q) { - assert(size == trunc_page_64(size)); /* Will the loop terminate? */ + 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); - 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; + loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH); - 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; + vm_page_lockspin_queues(); + } + if (reap_type == REAP_DATA_FLUSH || reap_type == REAP_TERMINATE) { - vm_object_lock(new_object); + if (p->busy || p->cleaning) { - while ((new_page = vm_page_alloc(new_object, new_offset)) - == VM_PAGE_NULL) { + vm_page_unlock_queues(); + /* + * free the pages reclaimed so far + */ + VM_OBJ_REAP_FREELIST(local_free_q, + disconnect_on_release); - vm_object_unlock(new_object); + PAGE_SLEEP(object, p, THREAD_UNINT); - if (!vm_page_wait(interruptible)) { - vm_object_deallocate(new_object); - vm_object_deallocate(src_object); - *_result_object = VM_OBJECT_NULL; - return(MACH_SEND_INTERRUPTED); + goto restart_after_sleep; } - vm_object_lock(new_object); + if (p->laundry) + vm_pageout_steal_laundry(p, TRUE); } - vm_object_unlock(new_object); + switch (reap_type) { - 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; + 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); - vm_object_lock(src_object); - vm_object_paging_begin(src_object); + 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; + } - fault_info.cluster_size = size; + assert(VM_PAGE_OBJECT(p) != kernel_object); - 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); + /* + * 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++; - switch(result) { - case VM_FAULT_SUCCESS: - result_page = _result_page; + break; - /* - * 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. - */ + 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)); - vm_object_unlock(result_page->object); - vm_page_copy(result_page, new_page); + if ((p->dirty || p->precious) && !p->error && object->alive) { - /* - * Let go of both pages (make them - * not busy, perform wakeup, activate). - */ - 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(); + assert(!object->internal); + + p->free_when_done = TRUE; + if (!p->laundry) { + vm_page_queues_remove(p, TRUE); /* - * Release paging references and - * top-level placeholder page, if any. + * 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); - vm_fault_cleanup(result_page->object, - top_page); + vm_object_paging_wait(object, THREAD_UNINT); - break; - - case VM_FAULT_RETRY: - break; + goto restart_after_sleep; + } + break; - case VM_FAULT_FICTITIOUS_SHORTAGE: - vm_page_more_fictitious(); - break; + case REAP_REAP: + break; + } + vm_page_free_prepare_queues(p); + 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; + } + vm_page_unlock_queues(); - case VM_FAULT_MEMORY_SHORTAGE: - if (vm_page_wait(interruptible)) - break; - /* fall thru */ + /* + * Free the remaining reclaimed pages + */ + if (reap_type == REAP_PURGEABLE) + pmap_flush(&pmap_flush_context_storage); - case VM_FAULT_INTERRUPTED: - vm_page_free(new_page); - vm_object_deallocate(new_object); - vm_object_deallocate(src_object); - *_result_object = VM_OBJECT_NULL; - return(MACH_SEND_INTERRUPTED); + VM_OBJ_REAP_FREELIST(local_free_q, + disconnect_on_release); +} - 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_page_lock_queues(); - vm_page_free(new_page); - vm_page_unlock_queues(); +void +vm_object_reap_async( + vm_object_t object) +{ + vm_object_lock_assert_exclusive(object); - vm_object_deallocate(new_object); - vm_object_deallocate(src_object); - *_result_object = VM_OBJECT_NULL; - return(error_code ? error_code: - KERN_MEMORY_ERROR); - } - } while (result != VM_FAULT_SUCCESS); - } + vm_object_reaper_lock_spin(); - /* - * Lose the extra reference, and return our object. - */ - vm_object_deallocate(src_object); - *_result_object = new_object; - return(KERN_SUCCESS); + vm_object_reap_count_async++; + + /* enqueue the VM object... */ + queue_enter(&vm_object_reaper_queue, object, + vm_object_t, cached_list); + + vm_object_reaper_unlock(); + + /* ... and wake up the reaper thread */ + thread_wakeup((event_t) &vm_object_reaper_queue); } -/* - * 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 */ +void +vm_object_reaper_thread(void) { - vm_object_t object = *_object; - memory_object_copy_strategy_t copy_strategy; - - 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); - } + vm_object_t object, shadow_object; - vm_object_lock(object); + vm_object_reaper_lock_spin(); - copy_strategy = object->copy_strategy; + while (!queue_empty(&vm_object_reaper_queue)) { + queue_remove_first(&vm_object_reaper_queue, + object, + vm_object_t, + cached_list); - switch (copy_strategy) { - case MEMORY_OBJECT_COPY_SYMMETRIC: + vm_object_reaper_unlock(); + vm_object_lock(object); + assert(object->terminating); + assert(!object->alive); + /* - * Symmetric copy strategy. - * Make another reference to the object. - * Leave object/offset unchanged. + * 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); + } - vm_object_reference_locked(object); - object->shadowed = TRUE; - vm_object_unlock(object); + shadow_object = + object->pageout ? VM_OBJECT_NULL : object->shadow; - /* - * Both source and destination must make - * shadows, and the source must be made - * read-only if not already. - */ + vm_object_reap(object); + /* cache is unlocked and object is no longer valid */ + object = VM_OBJECT_NULL; - *_src_needs_copy = TRUE; - *_dst_needs_copy = TRUE; + 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(); + } - break; + /* wait for more work... */ + assert_wait((event_t) &vm_object_reaper_queue, THREAD_UNINT); - case MEMORY_OBJECT_COPY_DELAY: - vm_object_unlock(object); - return(FALSE); + vm_object_reaper_unlock(); - default: - vm_object_unlock(object); - return(FALSE); - } - return(TRUE); + thread_block((thread_continue_t) vm_object_reaper_thread); + /*NOTREACHED*/ } -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. + * Routine: vm_object_pager_wakeup + * Purpose: Wake up anyone waiting for termination of a pager. */ -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 */ + +static void +vm_object_pager_wakeup( + memory_object_t pager) { - kern_return_t kr; - vm_object_t copy; - boolean_t check_ready = FALSE; - uint32_t try_failed_count = 0; + vm_object_hash_entry_t entry; + boolean_t waiting = FALSE; + lck_mtx_t *lck; /* - * 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. + * If anyone was waiting for the memory_object_terminate + * to be queued, wake them up now. */ - 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++; - } + 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); - /* - * 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.) - */ + if (entry != VM_OBJECT_HASH_ENTRY_NULL) { + if (waiting) + thread_wakeup((event_t) pager); + vm_object_hash_entry_free(entry); + } +} - vm_object_set_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL); - vm_object_unlock(src_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) +{ /* - * 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. + * Terminate the pager. */ - kr = KERN_FAILURE; /* XXX need to change memory_object.defs */ - if (kr != KERN_SUCCESS) { - return kr; - } + (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); + } /* - * Wait for the copy to arrive. + * Release reference to pager. */ - 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); + memory_object_deallocate(pager); +} - try_failed_count++; - mutex_pause(try_failed_count); /* wait a bit */ +/* + * 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; - vm_object_lock(src_object); - goto Retry; + 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.] + */ + + vm_object_lock(object); + object->can_persist = FALSE; + object->named = FALSE; + object->alive = 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); } - if (copy->size < src_offset+size) - copy->size = src_offset+size; + old_pager = object->pager; + object->pager = MEMORY_OBJECT_NULL; + if (old_pager != MEMORY_OBJECT_NULL) + memory_object_control_disable(object->pager_control); - if (!copy->pager_ready) - check_ready = TRUE; + /* + * Wait for the existing paging activity (that got + * through before we nulled out the pager) to subside. + */ + + vm_object_paging_wait(object, THREAD_UNINT); + vm_object_unlock(object); /* - * Return the copy. + * Terminate the object now. */ - *_result_object = copy; - vm_object_unlock(copy); - vm_object_unlock(src_object); + if (old_pager != MEMORY_OBJECT_NULL) { + vm_object_release_pager(old_pager, object->hashed); - /* 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); - } + /* + * 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); - return KERN_SUCCESS; + } + return(KERN_SUCCESS); } -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; +#if VM_OBJECT_CACHE + +#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 */ /* - * Routine: vm_object_copy_delayed [internal] - * - * Description: - * Copy the specified virtual memory object, using - * the asymmetric copy-on-write algorithm. + * vm_object_deactivate_all_pages * - * 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. + * Deactivate all pages in the specified object. (Keep its pages + * in memory even though it is no longer referenced.) * - * This routine will not block waiting for user-generated - * events. It is not interruptible. + * The object must be locked. */ -__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) +static void +vm_object_deactivate_all_pages( + vm_object_t object) { - 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; - - - 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. - */ + 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 - Retry: - - /* - * Wait for paging in progress. - */ - if (!src_object->true_share && src_object->paging_in_progress) { - if (src_object_shared == TRUE) { - vm_object_unlock(src_object); - - vm_object_lock(src_object); - src_object_shared = FALSE; + 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); + } + 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); } - vm_object_paging_wait(src_object, THREAD_UNINT); } - /* - * See whether we can reuse the result of a previous - * copy operation. - */ +#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 */ - old_copy = src_object->copy; - if (old_copy != VM_OBJECT_NULL) { - int lock_granted; - /* - * 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); - if (!lock_granted) { - vm_object_unlock(src_object); +/* + * 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 (collisions++ == 0) - copy_delayed_lock_contention++; - mutex_pause(collisions); +#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. */ - /* Heisenberg Rules */ - copy_delayed_lock_collisions++; +#define CHUNK_SIZE (PAGES_IN_A_CHUNK * PAGE_SIZE_64) /* Size of a chunk in bytes */ - if (collisions > copy_delayed_max_collisions) - copy_delayed_max_collisions = collisions; +typedef uint64_t chunk_state_t; - if (src_object_shared == TRUE) - vm_object_lock_shared(src_object); - else - vm_object_lock(src_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. + */ - goto Retry; - } +#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 - /* - * Determine whether the old copy object has - * been modified. - */ - 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). - */ +/* + * Return true if all pages in the chunk have not yet been processed. + */ - if (old_copy->size < copy_size) { - if (src_object_shared == TRUE) { - vm_object_unlock(old_copy); - vm_object_unlock(src_object); +#define CHUNK_NOT_COMPLETE(c) ((c) != 0) + +/* + * 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. + */ + +#define PAGE_ALREADY_HANDLED(c, p) (((c) & (1LL << (p))) == 0) + +/* + * Mark the page at offset 'p' in the bit map as having been processed. + */ + +#define MARK_PAGE_HANDLED(c, p) \ +MACRO_BEGIN \ + (c) = (c) & ~(1LL << (p)); \ +MACRO_END + + +/* + * Return true if the page at the given offset has been paged out. Object is + * locked upon entry and returned locked. + */ + +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) { + + if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset) + == VM_EXTERNAL_STATE_EXISTS) { + return TRUE; + } + } + return FALSE; +} + + + +/* + * madvise_free_debug + * + * 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. + */ +#if DEVELOPMENT || DEBUG +int madvise_free_debug = 1; +#else /* DEBUG */ +int madvise_free_debug = 0; +#endif /* DEBUG */ + +/* + * 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. + */ + +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; + + /* + * 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. + */ + + dwp = &dw_array[0]; + dw_count = 0; + dw_limit = DELAYED_WORK_LIMIT(DEFAULT_DELAYED_WORK_LIMIT); + + for(p = 0; size && CHUNK_NOT_COMPLETE(*chunk_state); p++, size -= PAGE_SIZE_64, offset += PAGE_SIZE_64, pmap_offset += PAGE_SIZE_64) { + + /* + * 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. + */ + + 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. + */ + + if ((m = vm_page_lookup(object, offset)) != VM_PAGE_NULL) { + + /* + * 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) && (!m->laundry)) { + int clear_refmod; + int pmap_options; + + dwp->dw_mask = 0; + + pmap_options = 0; + clear_refmod = VM_MEM_REFERENCED; + dwp->dw_mask |= DW_clear_reference; + + 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; + + 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; + } + + VM_COMPRESSOR_PAGER_STATE_CLR(object, offset); + + 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 ((m->vm_page_q_state != VM_PAGE_ON_THROTTLED_Q) && !(reusable_page || all_reusable)) + dwp->dw_mask |= DW_move_page; - vm_object_lock(src_object); - src_object_shared = FALSE; - goto Retry; + if (dwp->dw_mask) + VM_PAGE_ADD_DELAYED_WORK(dwp, m, + dw_count); + + 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); + + dwp = &dw_array[0]; + dw_count = 0; } + } + + } else { + + /* + * 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); + /* - * 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. + * 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. */ - copy_delayed_protect_iterate++; - queue_iterate(&src_object->memq, p, vm_page_t, listq) { - if (!p->fictitious && - p->offset >= old_copy->size && - p->offset < copy_size) { - if (p->wire_count > 0) { - vm_object_unlock(old_copy); - vm_object_unlock(src_object); + if ((kill_page) && (object->internal)) { - if (new_copy != VM_OBJECT_NULL) { - vm_object_unlock(new_copy); - vm_object_deallocate(new_copy); - } + VM_COMPRESSOR_PAGER_STATE_CLR(object, offset); - return VM_OBJECT_NULL; - } else { - pmap_page_protect(p->phys_page, - (VM_PROT_ALL & ~VM_PROT_WRITE)); - } + 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); } } - 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); - - if (new_copy != VM_OBJECT_NULL) { - vm_object_unlock(new_copy); - vm_object_deallocate(new_copy); } - return(old_copy); } + } + + 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); +} - /* - * 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->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); +/* + * 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. + */ - src_object_shared = FALSE; - goto Retry; - } - new_copy->size = copy_size; +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; - /* - * 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. - */ - assert((old_copy->shadow == src_object) && - (old_copy->shadow_offset == (vm_object_offset_t) 0)); + /* + * Get set to do a chunk. We'll do up to CHUNK_SIZE, but no more than the + * remaining size the caller asked for. + */ - } 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); + length = MIN(size, CHUNK_SIZE); - src_object_shared = FALSE; - goto Retry; - } + /* + * 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. + */ + + CHUNK_INIT(chunk_state, length); + object = orig_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. - * - * 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. + * 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. */ - copy_delayed_protect_iterate++; - queue_iterate(&src_object->memq, p, vm_page_t, listq) { - if (!p->fictitious && p->offset < copy_size) { - if (p->wire_count > 0) { - 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) { + 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, pfc, pmap, pmap_offset); + + vm_object_paging_end(object); + /* - * Make the old copy-object shadow the new one. - * It will receive no more pages from the original - * object. + * 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. */ - /* 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. */ + tmp_object = object->shadow; -#if TASK_SWAPPER - if (old_copy->res_count) { - VM_OBJ_RES_INCR(new_copy); - VM_OBJ_RES_DECR(src_object); + if (tmp_object) { + kill_page = FALSE; + reusable_page = FALSE; + all_reusable = FALSE; + offset += object->vo_shadow_offset; + vm_object_lock(tmp_object); } -#endif - vm_object_unlock(old_copy); /* done with old_copy */ + if (object != orig_object) + vm_object_unlock(object); + + object = tmp_object; } - /* - * Point the new copy at the existing object. - */ - 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 */ + if (object && object != orig_object) + vm_object_unlock(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); + return length; +} - XPR(XPR_VM_OBJECT, - "vm_object_copy_delayed: used copy object %X for source %X\n", - (integer_t)new_copy, (integer_t)src_object, 0, 0, 0); - return new_copy; -} /* - * 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. + * 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. */ -__private_extern__ kern_return_t -vm_object_copy_strategically( - register 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 *dst_object, /* OUT */ - vm_object_offset_t *dst_offset, /* OUT */ - boolean_t *dst_needs_copy) /* OUT */ + boolean_t kill_page, + boolean_t reusable_page, + struct pmap *pmap, + vm_map_offset_t pmap_offset) { - boolean_t result; - boolean_t interruptible = THREAD_ABORTSAFE; /* XXX */ - boolean_t object_lock_shared = FALSE; - memory_object_copy_strategy_t copy_strategy; + vm_object_size_t length; + boolean_t all_reusable; + pmap_flush_context pmap_flush_context_storage; - assert(src_object != VM_OBJECT_NULL); - - copy_strategy = src_object->copy_strategy; + /* + * 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. + */ - if (copy_strategy == MEMORY_OBJECT_COPY_DELAY) { - vm_object_lock_shared(src_object); - object_lock_shared = TRUE; - } else - vm_object_lock(src_object); + all_reusable = FALSE; +#if 11 /* - * The copy strategy is only valid if the memory manager - * is "ready". Internal objects are always ready. + * 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 - while (!src_object->internal && !src_object->pager_ready) { - wait_result_t wait_result; - - 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 ((reusable_page || all_reusable) && object->all_reusable) { + /* This means MADV_FREE_REUSABLE has been called twice, which + * is probably illegal. */ + return; } - /* - * Use the appropriate copy strategy. - */ + pmap_flush_context_init(&pmap_flush_context_storage); - 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 */ + while (size) { + length = deactivate_a_chunk(object, offset, size, kill_page, reusable_page, all_reusable, &pmap_flush_context_storage, pmap, pmap_offset); - 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; + size -= length; + offset += length; + pmap_offset += length; + } + pmap_flush(&pmap_flush_context_storage); + + if (all_reusable) { + if (!object->all_reusable) { + unsigned int reusable; + + 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++; } - break; + } else if (reusable_page) { + vm_page_stats_reusable.partial_reusable_calls++; + } +} - 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; +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; - case MEMORY_OBJECT_COPY_SYMMETRIC: - XPR(XPR_VM_OBJECT, "v_o_c_strategically obj 0x%x off 0x%x size 0x%x\n",(natural_t)src_object, src_offset, size, 0, 0); - vm_object_unlock(src_object); - result = KERN_MEMORY_RESTART_COPY; - break; +#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 - default: - panic("copy_strategically: bad strategy"); - result = KERN_INVALID_ARGUMENT; + 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); + } } - return(result); + + /* update global stats */ + OSAddAtomic(reusable-reused, &vm_page_stats_reusable.reusable_count); + vm_page_stats_reusable.reused += reused; + vm_page_stats_reusable.reusable += reusable; } /* - * vm_object_shadow: + * Routine: vm_object_pmap_protect * - * Create a new object which is backed by the - * specified existing object range. The source - * object reference is deallocated. + * Purpose: + * Reduces the permission for all physical + * pages in the specified object range. * - * The new object and offset into that object - * are returned in the source parameters. + * 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 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. */ -boolean_t vm_object_shadow_check = FALSE; -__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) +__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) { - register vm_object_t source; - register vm_object_t result; + vm_object_pmap_protect_options(object, offset, size, + pmap, pmap_start, prot, 0); +} - 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 +__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; - /* - * Determine if we really need a shadow. - */ + if (object == VM_OBJECT_NULL) + return; + size = vm_object_round_page(size); + offset = vm_object_trunc_page(offset); - 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_object_lock(object); + + 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; + + 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); + + pmap_flush_context_init(&pmap_flush_context_storage); + delayed_pmap_flush = FALSE; + + 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; } - /* - * Allocate a new object with the given length - */ + assert(object->internal); - if ((result = vm_object_allocate(length)) == VM_OBJECT_NULL) - panic("vm_object_shadow: no object for shadowing"); + 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; + } - /* - * 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. - */ + pmap_flush_context_init(&pmap_flush_context_storage); + delayed_pmap_flush = FALSE; - result->shadow_offset = *offset; + /* + * 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; - /* - * Return the new things - */ + end = offset + size; - *offset = 0; - *object = result; - return TRUE; -} + 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; + } + } -/* - * 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.] + } else { + vm_page_t p; + vm_object_offset_t end; + vm_object_offset_t target_off; + + end = offset + size; + + 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); + + 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) { + /* + * Must follow shadow chain to remove access + * to pages in shadowed objects. + */ + vm_object_t next_object; + + 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; + } + else { + /* + * End of chain - we are done. + */ + break; + } + } + else { + /* + * Pages in shadowed objects may never have + * write permission - we may stop here. + */ + break; + } + } + + vm_object_unlock(object); +} + +/* + * Routine: vm_object_copy_slowly * - * 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.] + * 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 addition to the lock on the object, the vm_object_cache_lock - * governs the associations. References gained through the - * association require use of the cache lock. + * 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*. * - * 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 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. * - * 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.] - */ - - -/* - * 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. + * 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. */ -vm_object_t -vm_object_enter( - memory_object_t pager, +__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 internal, - boolean_t init, - boolean_t named) + boolean_t interruptible, + vm_object_t *_result_object) /* 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; + vm_object_offset_t new_offset; - if (pager == MEMORY_OBJECT_NULL) - return(vm_object_allocate(size)); + struct vm_object_fault_info fault_info; - new_object = VM_OBJECT_NULL; - new_entry = VM_OBJECT_HASH_ENTRY_NULL; - must_init = init; + 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); + } /* - * Look for an object associated with this port. + * Prevent destruction of the source object while we copy. */ -Retry: - vm_object_cache_lock(); - do { - entry = vm_object_hash_lookup(pager, FALSE); - 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_cache_unlock(); - assert(new_entry == VM_OBJECT_HASH_ENTRY_NULL); - new_entry = vm_object_hash_entry_alloc(pager); - new_object = vm_object_allocate(size); - vm_object_cache_lock(); - } else { - /* - * Lookup failed twice, and we have something - * to insert; set the object. - */ - vm_object_hash_insert(new_entry); - entry = new_entry; - entry->object = new_object; - 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_cache_unlock(); - thread_block(THREAD_CONTINUE_NULL); - vm_object_cache_lock(); - } - } while (entry == VM_OBJECT_HASH_ENTRY_NULL); + vm_object_reference_locked(src_object); + vm_object_unlock(src_object); - object = entry->object; - assert(object != VM_OBJECT_NULL); + /* + * 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. + */ - if (!must_init) { - if (!vm_object_lock_try(object)) { + new_object = vm_object_allocate(size); + new_offset = 0; - vm_object_cache_unlock(); + assert(size == trunc_page_64(size)); /* Will the loop terminate? */ - try_failed_count++; - mutex_pause(try_failed_count); /* wait a bit */ + 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; - goto Retry; - } - assert(!internal || object->internal); - if (named) { - assert(!object->named); - object->named = TRUE; - } - if (object->ref_count == 0) { - XPR(XPR_VM_OBJECT_CACHE, - "vm_object_enter: removing %x from cache, head (%x, %x)\n", - (integer_t)object, - (integer_t)vm_object_cached_list.next, - (integer_t)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_lock_assert_exclusive(object); - object->ref_count++; - vm_object_res_reference(object); - vm_object_unlock(object); + 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; - VM_STAT_INCR(hits); - } - assert(object->ref_count > 0); + vm_object_lock(new_object); - VM_STAT_INCR(lookups); + while ((new_page = vm_page_alloc(new_object, new_offset)) + == VM_PAGE_NULL) { - vm_object_cache_unlock(); + vm_object_unlock(new_object); - XPR(XPR_VM_OBJECT, - "vm_o_enter: pager 0x%x obj 0x%x must_init %d\n", - (integer_t)pager, (integer_t)object, must_init, 0, 0); + 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); - /* - * If we raced to create a vm_object but lost, let's - * throw away ours. - */ + 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; - 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); + vm_object_lock(src_object); - if (must_init) { - memory_object_control_t control; + 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; + } - /* - * Allocate request port. - */ + vm_object_paging_begin(src_object); - control = memory_object_control_allocate(object); - assert (control != MEMORY_OBJECT_CONTROL_NULL); + 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); + } - vm_object_lock(object); - assert(object != kernel_object); + 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); - /* - * Copy the reference we were given. - */ + switch(result) { + case VM_FAULT_SUCCESS: + result_page = _result_page; + result_page_object = VM_PAGE_OBJECT(result_page); - 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; + /* + * Copy the page to the new object. + * + * POLICY DECISION: + * If result_page is clean, + * we could steal it instead + * of copying. + */ - vm_object_unlock(object); + vm_page_copy(result_page, new_page); + vm_object_unlock(result_page_object); - /* - * Let the pager know we're using it. - */ + /* + * 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); - (void) memory_object_init(pager, - object->pager_control, - PAGE_SIZE); + vm_object_lock(result_page_object); + PAGE_WAKEUP_DONE(result_page); - vm_object_lock(object); - if (named) - object->named = TRUE; - if (internal) { - object->pager_ready = TRUE; - vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY); - } + 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(); - object->pager_initialized = TRUE; - vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED); - } else { - vm_object_lock(object); - } + /* + * Release paging references and + * top-level placeholder page, if any. + */ - /* - * [At this point, the object must be locked] - */ + vm_fault_cleanup(result_page_object, + top_page); - /* - * Wait for the work above to be done by the first - * thread to map this object. - */ + break; + + case VM_FAULT_RETRY: + break; - while (!object->pager_initialized) { - vm_object_sleep(object, - VM_OBJECT_EVENT_INITIALIZED, - THREAD_UNINT); + 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); + + default: + panic("vm_object_copy_slowly: unexpected error" + " 0x%x from vm_fault_page()\n", result); + } + } while (result != VM_FAULT_SUCCESS); } - vm_object_unlock(object); - XPR(XPR_VM_OBJECT, - "vm_object_enter: vm_object %x, memory_object %x, internal %d\n", - (integer_t)object, (integer_t)object->pager, internal, 0,0); - return(object); + /* + * Lose the extra reference, and return our object. + */ + vm_object_deallocate(src_object); + *_result_object = new_object; + return(KERN_SUCCESS); } /* - * Routine: vm_object_pager_create + * Routine: vm_object_copy_quickly + * * Purpose: - * Create a memory object for an internal object. + * 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 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 object should be unlocked on entry and exit. */ -void -vm_object_pager_create( - register vm_object_t object) +/*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 */ { - memory_object_t pager; - vm_object_hash_entry_t entry; -#if MACH_PAGEMAP - vm_object_size_t size; - vm_external_map_t map; -#endif /* MACH_PAGEMAP */ + vm_object_t object = *_object; + memory_object_copy_strategy_t copy_strategy; - XPR(XPR_VM_OBJECT, "vm_object_pager_create, object 0x%X\n", - (integer_t)object, 0,0,0,0); + 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); + } - assert(object != kernel_object); + vm_object_lock(object); - if (memory_manager_default_check() != KERN_SUCCESS) - return; + copy_strategy = object->copy_strategy; - /* - * Prevent collapse or termination by holding a paging reference - */ + switch (copy_strategy) { + case MEMORY_OBJECT_COPY_SYMMETRIC: - vm_object_paging_begin(object); - if (object->pager_created) { /* - * Someone else got to it first... - * wait for them to finish initializing the ports + * Symmetric copy strategy. + * Make another reference to the object. + * Leave object/offset unchanged. */ - while (!object->pager_initialized) { - vm_object_sleep(object, - VM_OBJECT_EVENT_INITIALIZED, - THREAD_UNINT); - } - vm_object_paging_end(object); - return; - } - - /* - * Indicate that a memory object has been assigned - * before dropping the lock, to prevent a race. - */ - - object->pager_created = TRUE; - object->paging_offset = 0; - -#if MACH_PAGEMAP - size = object->size; -#endif /* MACH_PAGEMAP */ - vm_object_unlock(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 */ - - /* - * 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; + vm_object_reference_locked(object); + object->shadowed = TRUE; + vm_object_unlock(object); - /* acquire a reference for the default memory manager */ - dmm = memory_manager_default_reference(); + /* + * Both source and destination must make + * shadows, and the source must be made + * read-only if not already. + */ - assert(object->temporary); + *_src_needs_copy = TRUE; + *_dst_needs_copy = TRUE; - /* create our new memory object */ - (void) memory_object_create(dmm, object->size, &pager); + break; - memory_object_default_deallocate(dmm); - } + case MEMORY_OBJECT_COPY_DELAY: + vm_object_unlock(object); + return(FALSE); - entry = vm_object_hash_entry_alloc(pager); + default: + vm_object_unlock(object); + return(FALSE); + } + return(TRUE); +} - vm_object_cache_lock(); - vm_object_hash_insert(entry); +static int copy_call_count = 0; +static int copy_call_sleep_count = 0; +static int copy_call_restart_count = 0; - entry->object = object; - vm_object_cache_unlock(); +/* + * 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. + */ +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 */ +{ + kern_return_t kr; + vm_object_t copy; + boolean_t check_ready = FALSE; + uint32_t try_failed_count = 0; /* - * A reference was returned by - * memory_object_create(), and it is - * copied by vm_object_enter(). + * 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. */ - - if (vm_object_enter(pager, object->size, TRUE, TRUE, FALSE) != object) - panic("vm_object_pager_create: mismatch"); + 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++; + } /* - * Drop the reference we were passed. + * 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.) */ - memory_object_deallocate(pager); - vm_object_lock(object); + vm_object_set_wanted(src_object, VM_OBJECT_EVENT_COPY_CALL); + vm_object_unlock(src_object); /* - * Release the paging reference + * 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. */ - 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; + kr = KERN_FAILURE; /* XXX need to change memory_object.defs */ + if (kr != KERN_SUCCESS) { + return kr; + } - if ((pager = object->pager) != MEMORY_OBJECT_NULL) { - vm_object_hash_entry_t entry; + /* + * 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); - entry = vm_object_hash_lookup(pager, FALSE); - if (entry != VM_OBJECT_HASH_ENTRY_NULL) - entry->object = VM_OBJECT_NULL; + try_failed_count++; + mutex_pause(try_failed_count); /* wait a bit */ + + vm_object_lock(src_object); + goto Retry; } + if (copy->vo_size < src_offset+size) + copy->vo_size = src_offset+size; -} + if (!copy->pager_ready) + check_ready = TRUE; -/* - * 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; + /* + * Return the copy. + */ + *_result_object = copy; + vm_object_unlock(copy); + vm_object_unlock(src_object); -static boolean_t vm_object_collapse_allowed = TRUE; -static boolean_t vm_object_bypass_allowed = TRUE; + /* 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); + } -#if MACH_PAGEMAP -static int vm_external_discarded; -static int vm_external_collapsed; -#endif + return KERN_SUCCESS; +} -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; - backing_offset = object->shadow_offset; - size = object->size; + int collisions = 0; /* - * 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. + * 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. */ - - 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); + + copy_size = vm_object_round_page(copy_size); + 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. + */ + + 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; + + if (src_object_shared == TRUE) + vm_object_lock_shared(src_object); + else + vm_object_lock(src_object); + + goto Retry; + } + + /* + * Determine whether the old copy object has + * been modified. + */ + + 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 (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; + } /* - * Parent object has a real page. - * Throw away the backing object's - * page. + * 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. */ - VM_PAGE_FREE(p); + copy_delayed_protect_iterate++; + + pmap_flush_context_init(&pmap_flush_context_storage); + delayed_pmap_flush = FALSE; + + 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 !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_reference_shared(old_copy); + else + vm_object_reference_locked(old_copy); + vm_object_unlock(old_copy); + vm_object_unlock(src_object); - if (backing_object->pager != MEMORY_OBJECT_NULL) { - vm_object_hash_entry_t entry; + if (new_copy != VM_OBJECT_NULL) { + vm_object_unlock(new_copy); + vm_object_deallocate(new_copy); + } + return(old_copy); + } + + /* - * 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. + * 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; - assert(!object->paging_in_progress); - object->pager = backing_object->pager; - entry = vm_object_hash_lookup(object->pager, FALSE); - assert(entry != VM_OBJECT_HASH_ENTRY_NULL); - entry->object = object; - 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); + 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; - vm_object_cache_unlock(); + /* + * 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. + */ -#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 */ + assert((old_copy->shadow == src_object) && + (old_copy->vo_shadow_offset == (vm_object_offset_t) 0)); - /* - * 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; + } 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)); + 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", - (integer_t)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(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. - * [FBDP: that doesn't seem to be true any more] - * - * 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 > 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; - - vm_object_collapse_calls++; + boolean_t result; + boolean_t interruptible = THREAD_ABORTSAFE; /* XXX */ + boolean_t object_lock_shared = FALSE; + memory_object_copy_strategy_t copy_strategy; - if (! vm_object_collapse_allowed && - ! (can_bypass && vm_object_bypass_allowed)) { - return; - } + assert(src_object != VM_OBJECT_NULL); - XPR(XPR_VM_OBJECT, "vm_object_collapse, obj 0x%X\n", - (integer_t)object, 0,0,0,0); + copy_strategy = src_object->copy_strategy; - if (object == VM_OBJECT_NULL) - return; + if (copy_strategy == MEMORY_OBJECT_COPY_DELAY) { + vm_object_lock_shared(src_object); + object_lock_shared = TRUE; + } else + vm_object_lock(src_object); - original_object = object; + /* + * The copy strategy is only valid if the memory manager + * is "ready". Internal objects are always ready. + */ - 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; - } - - /* - * No pages in the object are currently - * being paged out, and - */ - if (object->paging_in_progress != 0) { - /* try and collapse the rest of the shadow chain */ - vm_object_lock(backing_object); - if (object != original_object) { - vm_object_unlock(object); - } - object = backing_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); + } + } - vm_object_lock(backing_object); + /* + * Use the appropriate copy strategy. + */ - /* - * ... - * 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) { - /* try and collapse the rest of the shadow chain */ - if (object != original_object) { - vm_object_unlock(object); - } - object = backing_object; - 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; - continue; + 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 */ - /* - * 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) { + 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; - XPR(XPR_VM_OBJECT, - "vm_object_collapse: %x to %x, pager %x, pager_control %x\n", - (integer_t)backing_object, (integer_t)object, - (integer_t)backing_object->pager, - (integer_t)backing_object->pager_control, 0); + 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 need the cache lock for collapsing, - * but we must not deadlock. - */ - - if (! vm_object_cache_lock_try()) { - if (object != original_object) { - vm_object_unlock(object); - } - vm_object_unlock(backing_object); - return; - } + 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; - /* - * 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; - 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 = 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; - - /* - * 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; - 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 -#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; - 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. - * - */ - - backing_offset = object->shadow_offset; - backing_rcount = backing_object->resident_page_count; - -#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 */ - - /* - * 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; - /* try and collapse the rest of the shadow chain */ - if (object != original_object) { - vm_object_unlock(object); - } - object = backing_object; - continue; - } + default: + panic("copy_strategically: bad strategy"); + result = KERN_INVALID_ARGUMENT; + } + return(result); +} - /* - * 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; +/* + * 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; - 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); - } +__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; - 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; - break; - } - p = (vm_page_t) queue_next(&p->listq); + source = *object; + assert(source != VM_OBJECT_NULL); + if (source == VM_OBJECT_NULL) + return FALSE; - } 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; - 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 - /* - * Walk through the offsets looking for pages in the - * backing object that show through to the object. - */ -#if MACH_PAGEMAP - if (backing_rcount || backing_object->existence_map) { -#else - if (backing_rcount) { -#endif /* MACH_PAGEMAP */ - offset = hint_offset; - - while((offset = - (offset + PAGE_SIZE_64 < object->size) ? - (offset + PAGE_SIZE_64) : 0) != hint_offset) { + /* + * 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). + */ - /* Until we get more than one lookup lock */ - if (lookups > 256) { - vm_object_collapse_delays++; - lookups = 0; - mutex_pause(0); - } + assert(source->copy_strategy != MEMORY_OBJECT_COPY_NONE); /* Purgeable objects shouldn't have shadow objects. */ - 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; - 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; - continue; - } - } + 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); + } - /* reset the offset hint for any objects deeper in the chain */ - object->cow_hint = (vm_offset_t)0; + /* + * Allocate a new object with the given length + */ - /* - * All interesting pages in the backing object - * already live in the parent or its pager. - * Thus we can bypass the backing object. - */ + if ((result = vm_object_allocate(length)) == VM_OBJECT_NULL) + panic("vm_object_shadow: no object for shadowing"); - vm_object_do_bypass(object, backing_object); - vm_object_collapse_do_bypass++; + /* + * 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. + */ - /* - * Try again with this object's new backing object. - */ + result->vo_shadow_offset = *offset; - continue; - } + /* + * Return the new things + */ - 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. + * All associations are created by memory_object_create_named + * for external pagers and vm_object_compressor_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.] + * + * 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.] */ -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) + +/* + * 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) { - register vm_page_t p, next; + 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; + + if (pager == MEMORY_OBJECT_NULL) + return(vm_object_allocate(size)); + + new_object = VM_OBJECT_NULL; + new_entry = VM_OBJECT_HASH_ENTRY_NULL; + must_init = init; /* - * One and two page removals are most popular. - * The factor of 16 here is somewhat arbitrary. - * It balances vm_object_lookup vs iteration. + * Look for an object associated with this port. */ +Retry: + lck = vm_object_hash_lock_spin(pager); + do { + entry = vm_object_hash_lookup(pager, FALSE); - 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); + 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); + + thread_block(THREAD_CONTINUE_NULL); + lck = vm_object_hash_lock_spin(pager); } - } else { - vm_object_page_remove_iterate++; + } while (entry == VM_OBJECT_HASH_ENTRY_NULL); - 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; + 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); -/* - * 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; + 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--; -__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; + 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); -#ifdef lint - next_offset++; -#endif /* lint */ + vm_object_hash_unlock(lck); + vm_object_unlock(object); - if (next_object != VM_OBJECT_NULL) { - return(FALSE); - } + VM_STAT_INCR(hits); + } else + vm_object_hash_unlock(lck); - if (prev_object == VM_OBJECT_NULL) { - return(TRUE); - } + assert(object->ref_count > 0); - XPR(XPR_VM_OBJECT, - "vm_object_coalesce: 0x%X prev_off 0x%X prev_size 0x%X next_size 0x%X\n", - (integer_t)prev_object, prev_offset, prev_size, next_size, 0); + VM_STAT_INCR(lookups); - vm_object_lock(prev_object); + XPR(XPR_VM_OBJECT, + "vm_o_enter: pager 0x%x obj 0x%x must_init %d\n", + pager, object, must_init, 0, 0); /* - * Try to collapse the object first + * If we raced to create a vm_object but lost, let's + * throw away ours. */ - 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 (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); + } - 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)) { - vm_object_unlock(prev_object); - return(FALSE); - } - - vm_object_coalesce_count++; + if (new_entry != VM_OBJECT_HASH_ENTRY_NULL) + vm_object_hash_entry_free(new_entry); - /* - * 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) { + memory_object_control_t control; - /* - * 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. + * Allocate request port. */ - assert(prev_object->existence_map == VM_EXTERNAL_NULL); -#endif /* MACH_PAGEMAP */ - prev_object->size = newsize; - } - vm_object_unlock(prev_object); - return(TRUE); -} + control = memory_object_control_allocate(object); + assert (control != MEMORY_OBJECT_CONTROL_NULL); -/* - * 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 */ -{ - int num_pages; - int i; - vm_page_t m; - vm_page_t old_page; - vm_object_offset_t addr; + vm_object_lock(object); + assert(object != kernel_object); - num_pages = atop_64(size); + /* + * Copy the reference we were given. + */ - for (i = 0; i < num_pages; i++, offset += PAGE_SIZE_64) { + 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; - addr = (*map_fn)(map_fn_data, offset); + vm_object_unlock(object); - while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL) - vm_page_more_fictitious(); + /* + * Let the pager know we're using it. + */ - vm_object_lock(object); - if ((old_page = vm_page_lookup(object, offset)) - != VM_PAGE_NULL) - { - vm_page_lock_queues(); - vm_page_free(old_page); - vm_page_unlock_queues(); - } + (void) memory_object_init(pager, + object->pager_control, + PAGE_SIZE); - vm_page_init(m, 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); + 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); + } - PAGE_WAKEUP_DONE(m); - vm_object_unlock(object); + object->pager_initialized = TRUE; + vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED); + } else { + vm_object_lock(object); } -} -#include - -#if MACH_KDB -#include -#include + /* + * [At this point, the object must be locked] + */ -#define printf kdbprintf + /* + * Wait for the work above to be done by the first + * thread to map this object. + */ -extern boolean_t vm_object_cached( - vm_object_t object); + while (!object->pager_initialized) { + vm_object_sleep(object, + VM_OBJECT_EVENT_INITIALIZED, + THREAD_UNINT); + } + vm_object_unlock(object); -extern void print_bitstring( - char byte); + XPR(XPR_VM_OBJECT, + "vm_object_enter: vm_object %x, memory_object %x, internal %d\n", + object, object->pager, internal, 0,0); + return(object); +} -boolean_t vm_object_print_pages = FALSE; +/* + * 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 -print_bitstring( - char byte) +vm_object_compressor_pager_create( + vm_object_t object) { - 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')); -} + memory_object_t pager; + vm_object_hash_entry_t entry; + lck_mtx_t *lck; + vm_object_t pager_object = VM_OBJECT_NULL; -boolean_t -vm_object_cached( - register vm_object_t object) -{ - register vm_object_t o; + assert(object != kernel_object); - queue_iterate(&vm_object_cached_list, o, vm_object_t, cached_list) { - if (object == o) { - return TRUE; + /* + * Prevent collapse or termination by holding a paging reference + */ + + 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; } - return FALSE; -} -#if MACH_PAGEMAP -/* - * vm_external_print: [ debug ] - */ -void -vm_external_print( - vm_external_map_t emap, - vm_size_t size) -{ - if (emap == VM_EXTERNAL_NULL) { - printf("0 "); - } else { - vm_size_t existence_size = stob(size); - printf("{ size=%d, map=[", 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"); + /* + * Indicate that a memory object has been assigned + * before dropping the lock, to prevent a race. + */ + + object->pager_created = TRUE; + object->paging_offset = 0; + + vm_object_unlock(object); + + 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); } - return; -} -#endif /* MACH_PAGEMAP */ -int -vm_follow_object( - vm_object_t object) -{ - int count = 0; - int orig_db_indent = db_indent; + /* + * 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); - while (TRUE) { - if (object == VM_OBJECT_NULL) { - db_indent = orig_db_indent; - return count; + /* 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); } + } + + entry = vm_object_hash_entry_alloc(pager); + + 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); - count += 1; + /* + * A reference was returned by + * memory_object_create(), and it is + * copied by vm_object_enter(). + */ - 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); + pager_object = vm_object_enter(pager, object->vo_size, TRUE, TRUE, FALSE); - db_indent += 2; - object = object->shadow; + 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); } + /* + * 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_print: [ debug ] + * Routine: vm_object_remove + * Purpose: + * Eliminate the pager/object association + * for this pager. + * Conditions: + * The object cache must be locked. */ -void -vm_object_print(db_expr_t db_addr, __unused boolean_t have_addr, - __unused db_expr_t arg_count, __unused char *modif) +__private_extern__ void +vm_object_remove( + vm_object_t object) { - vm_object_t object; - register vm_page_t p; - const char *s; - - register int count; + memory_object_t pager; - object = (vm_object_t) (long) db_addr; - if (object == VM_OBJECT_NULL) - return; + if ((pager = object->pager) != MEMORY_OBJECT_NULL) { + vm_object_hash_entry_t entry; - iprintf("object 0x%x\n", object); + entry = vm_object_hash_lookup(pager, FALSE); + if (entry != VM_OBJECT_HASH_ENTRY_NULL) + entry->object = VM_OBJECT_NULL; + } - db_indent += 2; +} - 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); +/* + * 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; - 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; +static boolean_t vm_object_collapse_allowed = TRUE; +static boolean_t vm_object_bypass_allowed = TRUE; - case MEMORY_OBJECT_COPY_CALL: - printf("copy_call"); - break; +unsigned long vm_object_collapse_encrypted = 0; - case MEMORY_OBJECT_COPY_DELAY: - printf("copy_delay"); - break; +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; - case MEMORY_OBJECT_COPY_SYMMETRIC: - printf("copy_symmetric"); - break; + vm_counters.do_collapse_compressor++; - case MEMORY_OBJECT_COPY_INVALID: - printf("copy_invalid"); - break; + vm_object_lock_assert_exclusive(object); + vm_object_lock_assert_exclusive(backing_object); - 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); - - 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 */ + size = object->vo_size; - 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++; + /* + * Move all compressed pages from backing_object + * to the parent. + */ - printf("(off=0x%llX,page=%p)", p->offset, p); - p = (vm_page_t) queue_next(&p->listq); - } - if (count != 0) { - printf("\n"); + 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; } - } - db_indent -= 2; -} + backing_offset = (backing_pager_offset - + backing_object->paging_offset); + new_offset = backing_offset - object->vo_shadow_offset; -/* - * vm_object_find [ debug ] - * - * Find all tasks which reference the given vm_object. - */ + if (new_offset >= object->vo_size) { + /* we're out of the scope of "object": done */ + break; + } -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) -{ - 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 ((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. */ - if (entry->is_sub_map) - continue; - if (entry) - obj = entry->object.vm_object; - else - continue; - - 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; - } + continue; } - } - return(found); + /* + * 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)); + } } -#endif /* MACH_KDB */ - -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) +/* + * 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. + * + */ +static void +vm_object_do_collapse( + vm_object_t object, + vm_object_t backing_object) { - ppnum_t base_page; - vm_object_offset_t base_offset; + vm_page_t p, pp; + vm_object_offset_t new_offset, backing_offset; + vm_object_size_t size; + vm_object_lock_assert_exclusive(object); + vm_object_lock_assert_exclusive(backing_object); - if(!object->private) - return KERN_FAILURE; + assert(object->purgable == VM_PURGABLE_DENY); + assert(backing_object->purgable == VM_PURGABLE_DENY); - base_page = phys_page; + backing_offset = object->vo_shadow_offset; + size = object->vo_size; - 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_page_lockspin_queues(); - m->fictitious = FALSE; - m->private = TRUE; - m->phys_page = base_page; - if(!m->busy) { - m->busy = TRUE; - } - if(!m->absent) { - m->absent = TRUE; - } - m->list_req_pending = TRUE; - vm_page_unlock_queues(); - } - } 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 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 { + /* + * 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_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); /* - * 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 ? + * Parent object has a real page. + * Throw away the backing object's + * page. */ - m->encrypted = FALSE; - - } else { - while ((m = vm_page_grab_fictitious()) - == VM_PAGE_NULL) - vm_page_more_fictitious(); - vm_page_lockspin_queues(); - m->fictitious = FALSE; - m->private = TRUE; - m->phys_page = base_page; - m->list_req_pending = TRUE; - m->absent = TRUE; - m->unusual = TRUE; - vm_page_unlock_queues(); - vm_page_insert(m, object, base_offset); + VM_PAGE_FREE(p); } - 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->shadow_offset = (vm_object_offset_t)phys_page << PAGE_SHIFT; - object->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. - */ + if (vm_object_collapse_compressor_allowed && + object->pager != MEMORY_OBJECT_NULL && + backing_object->pager != MEMORY_OBJECT_NULL) { -__private_extern__ kern_return_t -memory_object_free_from_cache( - __unused host_t host, - memory_object_pager_ops_t pager_ops, - int *count) -{ + /* move compressed pages from backing_object to object */ + vm_object_do_collapse_compressor(object, backing_object); - int object_released = 0; + } else if (backing_object->pager != MEMORY_OBJECT_NULL) { + vm_object_hash_entry_t entry; - register vm_object_t object = VM_OBJECT_NULL; - vm_object_t shadow; + 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. + */ -/* - if(host == HOST_NULL) - return(KERN_INVALID_ARGUMENT); -*/ + assert(!object->paging_in_progress); + assert(!object->activity_in_progress); + assert(!object->pager_created); + assert(object->pager == NULL); + object->pager = backing_object->pager; - try_again: - vm_object_cache_lock(); + if (backing_object->hashed) { + lck_mtx_t *lck; - 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--; + 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); - /* - * 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. - */ + 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. + */ + + 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)); - assert(object->pager_initialized); - assert(object->ref_count == 0); - vm_object_lock_assert_exclusive(object); - object->ref_count++; + /* + * 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); - /* - * 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; + 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++; } + return; } - vm_object_cache_unlock(); - *count = object_released; - return KERN_SUCCESS; -} + assert(backing_object->pager == NULL); + backing_object->alive = FALSE; + vm_object_unlock(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; + XPR(XPR_VM_OBJECT, "vm_object_collapse, collapsed 0x%X\n", + backing_object, 0,0,0,0); - *control = MEMORY_OBJECT_CONTROL_NULL; - if (pager == MEMORY_OBJECT_NULL) - return KERN_INVALID_ARGUMENT; +#if VM_OBJECT_TRACKING + if (vm_object_tracking_inited) { + btlog_remove_entries_for_element(vm_object_tracking_btlog, + backing_object); + } +#endif /* VM_OBJECT_TRACKING */ - vm_object_cache_lock(); - 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_lock_destroy(backing_object); - vm_object_cache_unlock(); - if ((object = vm_object_enter(pager, size, FALSE, FALSE, TRUE)) - == VM_OBJECT_NULL) { - return(KERN_INVALID_OBJECT); - } + zfree(vm_object_zone, backing_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) +static void +vm_object_do_bypass( + vm_object_t object, + vm_object_t backing_object) { - vm_object_t 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_cache_lock(); - object = memory_object_control_to_vm_object(control); - if (object == VM_OBJECT_NULL) { - vm_object_cache_unlock(); - return (KERN_INVALID_ARGUMENT); +#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 */ -restart: - vm_object_lock(object); - - if (object->terminating && wait_on_terminating) { - vm_object_cache_unlock(); - vm_object_wait(object, - VM_OBJECT_EVENT_PAGING_IN_PROGRESS, - THREAD_UNINT); - vm_object_cache_lock(); - goto restart; + 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; } - - if (!object->alive) { - vm_object_cache_unlock(); - vm_object_unlock(object); - return KERN_FAILURE; + + /* + * 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 { - if (object->named == TRUE) { - vm_object_cache_unlock(); + /* + * Drop locks so that we can deallocate + * the backing object. + */ + +#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); - return KERN_SUCCESS; - } - if((object->ref_count == 0) && (!object->terminating)){ - 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", - (integer_t)object, - (integer_t)vm_object_cached_list.next, - (integer_t)vm_object_cached_list.prev, 0,0); - } + vm_object_unlock(backing_object); + vm_object_deallocate(backing_object); - vm_object_cache_unlock(); + /* + * 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. + */ - 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_lock(object); + vm_object_activity_end(object); } - vm_object_unlock(object); - return (KERN_SUCCESS); + + object_bypasses++; } - + /* - * vm_object_release_name: + * vm_object_collapse: * - * 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. + * 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. * - * 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. */ +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_release_name( - vm_object_t object, - int flags) +__private_extern__ void +vm_object_collapse( + vm_object_t object, + vm_object_offset_t hint_offset, + boolean_t can_bypass) { - vm_object_t shadow; - boolean_t original_object = TRUE; + 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; - while (object != VM_OBJECT_NULL) { + vm_object_collapse_calls++; + + if (! vm_object_collapse_allowed && + ! (can_bypass && vm_object_bypass_allowed)) { + return; + } + + XPR(XPR_VM_OBJECT, "vm_object_collapse, obj 0x%X\n", + object, 0,0,0,0); + + if (object == VM_OBJECT_NULL) + return; + + original_object = 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. + */ + 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++; /* - * The cache holds a reference (uncounted) to - * the object. We must locke it before removing - * the object. - * + * Verify that the conditions are right for either + * collapse or bypass: */ - - vm_object_cache_lock(); - 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. + * 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); + } - 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); - vm_object_cache_unlock(); - thread_block(THREAD_CONTINUE_NULL); + /* + * 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; } - if (((object->ref_count > 1) - && (flags & MEMORY_OBJECT_TERMINATE_IDLE)) - || (object->terminating)) { - vm_object_unlock(object); - vm_object_cache_unlock(); - return KERN_FAILURE; - } else { - if (flags & MEMORY_OBJECT_RELEASE_NO_OP) { + /* + * ... + * 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); - vm_object_cache_unlock(); - return KERN_SUCCESS; } + object = backing_object; + object_lock_type = backing_object_lock_type; + continue; } - - if ((flags & MEMORY_OBJECT_RESPECT_CACHE) && - (object->ref_count == 1)) { - if(original_object) - object->named = FALSE; - vm_object_unlock(object); - vm_object_cache_unlock(); - /* 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; + + /* + * 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; } - 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; + + /* + * 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 (shadow != VM_OBJECT_NULL) { - original_object = FALSE; - object = shadow; + + /* + * 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; } - 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); - vm_object_cache_unlock(); - return KERN_SUCCESS; - } - } - /*NOTREACHED*/ - assert(0); - return KERN_FAILURE; -} + /* + * 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. + */ +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. + */ +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_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)); + +#undef __TRANSPOSE_FIELD + + retval = KERN_SUCCESS; + +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 (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; +} -__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; +/* + * 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; +extern int ignore_is_ssd; - XPR(XPR_MEMORY_OBJECT, - "vm_o_lock_request, obj 0x%X off 0x%X size 0x%X flags %X prot %X\n", - (integer_t)object, offset, size, - (((should_return&1)<<1)|should_flush), prot); +/* + * 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. + */ + unsigned int preheat_max_bytes = MAX_UPL_TRANSFER_BYTES; +unsigned int preheat_min_bytes = (1024 * 32); - /* - * 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); +__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) +{ + 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; - size = round_page_64(size); + assert( !(*length & PAGE_MASK)); + assert( !(*start & PAGE_MASK_64)); /* - * Lock the object, and acquire a paging reference to - * prevent the memory_object reference from being released. + * remember maxiumum length of run requested + */ + max_length = *length; + /* + * we'll always return a cluster size of at least + * 1 page, since the original fault must always + * be processed */ + *length = PAGE_SIZE; + *io_streaming = 0; + + 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; + vm_object_lock(object); - vm_object_paging_begin(object); - (void)vm_object_update(object, - offset, size, NULL, NULL, should_return, flags, prot); + if (object->pager == MEMORY_OBJECT_NULL) + goto out; /* pager is gone for this object, nothing more to do */ - vm_object_paging_end(object); - vm_object_unlock(object); + if (!ignore_is_ssd) + vnode_pager_get_isSSD(object->pager, &isSSD); - return (KERN_SUCCESS); -} + min_ph_size = round_page(preheat_min_bytes); + max_ph_size = round_page(preheat_max_bytes); -/* - * 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 and page queues are locked, the object must be a - * purgeable object with no delayed copies pending. - */ -unsigned int -vm_object_purge(vm_object_t object) -{ - vm_page_t p, next; - unsigned int num_purged_pages; - vm_page_t local_freeq; - unsigned long local_freed; - int purge_loop_quota; -/* free pages as soon as we gather PURGE_BATCH_FREE_LIMIT pages to free */ -#define PURGE_BATCH_FREE_LIMIT 50 -/* release page queues lock every PURGE_LOOP_QUOTA iterations */ -#define PURGE_LOOP_QUOTA 100 - - num_purged_pages = 0; - if (object->purgable == VM_PURGABLE_DENY) - return num_purged_pages; + 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); + } - assert(object->purgable != VM_PURGABLE_NONVOLATILE); - object->purgable = VM_PURGABLE_EMPTY; + if (max_ph_size & PAGE_MASK_64) { + max_ph_size = trunc_page(max_ph_size); + } + } - assert(object->copy == VM_OBJECT_NULL); - assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE); - purge_loop_quota = PURGE_LOOP_QUOTA; + if (min_ph_size < PAGE_SIZE) + min_ph_size = PAGE_SIZE; - local_freeq = VM_PAGE_NULL; - local_freed = 0; + 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; - /* - * Go through the object's resident pages and try and discard them. - */ - next = (vm_page_t)queue_first(&object->memq); - while (!queue_end(&object->memq, (queue_entry_t)next)) { - p = next; - next = (vm_page_t)queue_next(&next->listq); + if (max_length > max_ph_size) + max_length = max_ph_size; - if (purge_loop_quota-- == 0) { - /* - * Avoid holding the page queues lock for too long. - * Let someone else take it for a while if needed. - * Keep holding the object's lock to guarantee that - * the object's page list doesn't change under us - * while we yield. - */ - if (local_freeq != VM_PAGE_NULL) { + if (max_length <= PAGE_SIZE) + goto out; + + if (object->internal) + object_size = object->vo_size; + else + vnode_pager_get_object_size(object->pager, &object_size); + + object_size = round_page_64(object_size); + + 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; + } + + } + switch (behavior) { + + default: + behavior = VM_BEHAVIOR_DEFAULT; + + case VM_BEHAVIOR_DEFAULT: + if (object->internal && fault_info->user_tag == VM_MEMORY_STACK) + goto out; + + if (sequential_run >= (3 * PAGE_SIZE)) { + pre_heat_size = sequential_run + PAGE_SIZE; + + if (sequential_behavior == VM_BEHAVIOR_SEQUENTIAL) + look_behind = FALSE; + else + look_ahead = FALSE; + + *io_streaming = 1; + } else { + + if (object->pages_created < (20 * (min_ph_size >> PAGE_SHIFT))) { + /* + * prime the pump + */ + pre_heat_size = min_ph_size; + } else { /* - * Flush our queue of pages to free. + * 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 */ - vm_page_free_list(local_freeq); - local_freeq = VM_PAGE_NULL; - local_freed = 0; - } - mutex_yield(&vm_page_queue_lock); + pre_heat_size = (max_length * (uint64_t)object->pages_used) / object->pages_created; - /* resume with the current page and a new quota */ - purge_loop_quota = PURGE_LOOP_QUOTA; - } - - - if (p->busy || p->cleaning || p->laundry || - p->list_req_pending) { - /* page is being acted upon, so don't mess with it */ - continue; - } - if (p->wire_count) { - /* don't discard a wired page */ - continue; + if (pre_heat_size < min_ph_size) + pre_heat_size = min_ph_size; + else + pre_heat_size = round_page(pre_heat_size); + } } + break; - assert(!p->laundry); - assert(p->object != kernel_object); + case VM_BEHAVIOR_RANDOM: + if ((pre_heat_size = cluster_size) <= PAGE_SIZE) + goto out; + break; - /* we can discard this page */ + case VM_BEHAVIOR_SEQUENTIAL: + if ((pre_heat_size = cluster_size) == 0) + pre_heat_size = sequential_run + PAGE_SIZE; + look_behind = FALSE; + *io_streaming = 1; - /* advertize that this page is in a transition state */ - p->busy = TRUE; + break; - if (p->pmapped == TRUE) { - /* unmap the page */ - int refmod_state; + case VM_BEHAVIOR_RSEQNTL: + if ((pre_heat_size = cluster_size) == 0) + pre_heat_size = sequential_run + PAGE_SIZE; + look_ahead = FALSE; + *io_streaming = 1; - refmod_state = pmap_disconnect(p->phys_page); - if (refmod_state & VM_MEM_MODIFIED) { - p->dirty = TRUE; - } + break; + + } + throttle_limit = (uint32_t) max_length; + assert(throttle_limit == max_length); + + 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 (behavior == VM_BEHAVIOR_DEFAULT && (pre_heat_size > min_ph_size)) { + + 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 (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); - if (p->dirty || p->precious) { - /* we saved the cost of cleaning this page ! */ - num_purged_pages++; - vm_page_purged_count++; + 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; - vm_page_free_prepare(p); + 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; - /* ... and put it on our queue of pages to free */ - assert(p->pageq.next == NULL && - p->pageq.prev == NULL); - p->pageq.next = (queue_entry_t) local_freeq; - local_freeq = p; - if (++local_freed >= PURGE_BATCH_FREE_LIMIT) { - /* flush our queue of pages to free */ - vm_page_free_list(local_freeq); - local_freeq = VM_PAGE_NULL; - local_freed = 0; + 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 (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); - /* flush our local queue of pages to free one last time */ - if (local_freeq != VM_PAGE_NULL) { - vm_page_free_list(local_freeq); - local_freeq = VM_PAGE_NULL; - local_freed = 0; + /* + * 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; - return num_purged_pages; + vm_object_unlock(object); + + DTRACE_VM1(clustersize, vm_size_t, *length); } + /* - * 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. + * 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_purgable_control( - vm_object_t object, - vm_purgable_t control, - int *state) +vm_object_page_op( + vm_object_t object, + vm_object_offset_t offset, + int ops, + ppnum_t *phys_entry, + int *flags) { - 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_page_t dst_page; - /* - * 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); + vm_object_lock(object); - /* - * Execute the desired operation. - */ - if (control == VM_PURGABLE_GET_STATE) { - *state = old_state; - return KERN_SUCCESS; + 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; + } + } + if(object->phys_contiguous) { + vm_object_unlock(object); + return KERN_INVALID_OBJECT; } - new_state = *state & VM_PURGABLE_STATE_MASK; - switch (new_state) { - case VM_PURGABLE_DENY: - case VM_PURGABLE_NONVOLATILE: - object->purgable = new_state; - - if (old_state != VM_PURGABLE_NONVOLATILE) { - vm_page_lock_queues(); - assert(vm_page_purgeable_count >= - object->resident_page_count); - vm_page_purgeable_count -= object->resident_page_count; - - if (old_state==VM_PURGABLE_VOLATILE) { - 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); + while(TRUE) { + if((dst_page = vm_page_lookup(object,offset)) == VM_PAGE_NULL) { + vm_object_unlock(object); + return KERN_FAILURE; + } - vm_purgeable_token_delete_first(queue); - assert(queue->debug_count_objects>=0); - }; - vm_page_unlock_queues(); + /* 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; } - break; - case VM_PURGABLE_VOLATILE: + if (ops & UPL_POP_DUMP) { + if (dst_page->pmapped == TRUE) + pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page)); - if ((old_state != VM_PURGABLE_NONVOLATILE) && (old_state != VM_PURGABLE_VOLATILE)) + VM_PAGE_FREE(dst_page); 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_FIFO]; - 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) { - /* try to add token... this can fail */ - vm_page_lock_queues(); - - kern_return_t result = vm_purgeable_token_add(queue); - if (result != KERN_SUCCESS) { - vm_page_unlock_queues(); - return result; - } - vm_page_purgeable_count += object->resident_page_count; - vm_page_unlock_queues(); + if (flags) { + *flags = 0; - object->purgable = new_state; + /* Get the condition of flags before requested ops */ + /* are undertaken */ - /* object should not be on a queue */ - assert(object->objq.next == NULL && object->objq.prev == NULL); + 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; } - 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; - - /* 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(); - assert(result==KERN_SUCCESS); /* this should never fail since we just freed a token */ + /* 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); } - }; - vm_purgeable_object_add(object, queue, (*state&VM_VOLATILE_GROUP_MASK)>>VM_VOLATILE_GROUP_SHIFT ); - - assert(queue->debug_count_objects>=0); - - break; + 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; + } + 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); + } + } - case VM_PURGABLE_EMPTY: - if (old_state != new_state) - { - assert(old_state==VM_PURGABLE_NONVOLATILE || old_state==VM_PURGABLE_VOLATILE); - if(old_state==VM_PURGABLE_VOLATILE) { - 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); - vm_page_lock_queues(); - vm_purgeable_token_delete_first(old_queue); + 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); } + } - if (old_state==VM_PURGABLE_NONVOLATILE) { - vm_page_purgeable_count += object->resident_page_count; - vm_page_lock_queues(); - } - (void) vm_object_purge(object); - vm_page_unlock_queues(); + 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); } - break; + break; } - *state = old_state; + vm_object_unlock(object); return KERN_SUCCESS; -} - -#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. + * 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. */ -__private_extern__ void -vm_object_res_reference( - vm_object_t object) +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_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; + vm_object_offset_t offset; + vm_page_t dst_page; - assert(object->ref_count >= object->res_count); - vm_object_lock(tmp_object); - if (object != orig_object) - vm_object_unlock(object); - object = tmp_object; + 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 (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( - register 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, - vm_size_t nval) -{ - vm_object_cached_max = nval; - vm_object_cache_trim(FALSE); - 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. - */ -kern_return_t -vm_object_transpose( - vm_object_t object1, - vm_object_t object2, - vm_object_size_t transpose_size) -{ - vm_object_t tmp_object; - kern_return_t retval; - boolean_t object1_locked, object2_locked; - boolean_t object1_paging, object2_paging; - vm_page_t page; - vm_object_offset_t page_offset; + if (object->phys_contiguous) { + vm_object_unlock(object); + return KERN_INVALID_OBJECT; + } + + offset = offset_beg & ~PAGE_MASK_64; - tmp_object = VM_OBJECT_NULL; - object1_locked = FALSE; object2_locked = FALSE; - object1_paging = FALSE; object2_paging = FALSE; + 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 (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; - } + if (dst_page->pmapped == TRUE) + pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page)); - 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; - } - /* - * Since we're about to mess with the object's backing store, - * mark it as "paging_in_progress". Note that this is not 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"). - */ - vm_object_paging_begin(object1); - object1_paging = TRUE; - vm_object_unlock(object1); - object1_locked = FALSE; + VM_PAGE_FREE(dst_page); - /* - * 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; + } else if ((ops & UPL_ROP_ABSENT) + && (!dst_page->absent || dst_page->busy)) { + break; + } + } else if (ops & UPL_ROP_PRESENT) + break; + + offset += PAGE_SIZE; } - vm_object_paging_begin(object2); - object2_paging = TRUE; - vm_object_unlock(object2); - object2_locked = FALSE; + vm_object_unlock(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); - vm_object_paging_begin(tmp_object); - tmp_object->can_persist = FALSE; + 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; + } + } + return KERN_SUCCESS; +} - /* - * 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) { - vm_object_lock(object1); - vm_object_lock(object2); - } else { - vm_object_lock(object2); - vm_object_lock(object1); +/* + * 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; + + page_num = pmap_find_phys(kernel_pmap, base_vaddr); + + if (!page_num) { + retval = KERN_FAILURE; + goto out; } - object1_locked = TRUE; - object2_locked = TRUE; - 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; + pager_object = memory_object_control_to_vm_object(object); + + if (!pager_object) { + retval = KERN_FAILURE; + goto out; } + 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); - /* - * 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); - } - 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); - } - assert(queue_empty(&object1->memq)); - } else { - /* transfer object1's pages to tmp_object */ - vm_page_lock_queues(); - while (!queue_empty(&object1->memq)) { - page = (vm_page_t) queue_first(&object1->memq); - page_offset = page->offset; - vm_page_remove(page); - page->offset = page_offset; - queue_enter(&tmp_object->memq, page, vm_page_t, listq); - } - vm_page_unlock_queues(); - 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); - } - 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 (retval != KERN_SUCCESS) { + if (pager_object->private != clobbered_private) { + vm_object_lock(pager_object); + pager_object->private = clobbered_private; + vm_object_unlock(pager_object); } - assert(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 +out: + return retval; +} - /* "size" should be identical */ - assert(object1->size == object2->size); - /* "Lock" refers to the object not its contents */ - /* "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 */ - /* 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); - } - if (object2->pager_control != MEMORY_OBJECT_CONTROL_NULL) { - memory_object_control_collapse(object2->pager_control, - object2); +uint32_t scan_object_collision = 0; + +void +vm_object_lock(vm_object_t object) +{ + if (object == vm_pageout_scan_wants_object) { + scan_object_collision++; + mutex_pause(2); } - __TRANSPOSE_FIELD(copy_strategy); - /* "paging_in_progress" refers to the object not its contents */ - assert(object1->paging_in_progress); - assert(object2->paging_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" should be NULL */ - assert(object1->cached_list.prev == NULL); - assert(object1->cached_list.next == NULL); - assert(object2->cached_list.prev == NULL); - assert(object2->cached_list.next == 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); - __TRANSPOSE_FIELD(not_in_use); -#ifdef UPL_DEBUG - /* "uplq" refers to the object not its contents (see upl_transpose()) */ + lck_rw_lock_exclusive(&object->Lock); +#if DEVELOPMENT || DEBUG + object->Lock_owner = current_thread(); #endif +} -#undef __TRANSPOSE_FIELD +boolean_t +vm_object_lock_avoid(vm_object_t object) +{ + if (object == vm_pageout_scan_wants_object) { + scan_object_collision++; + return TRUE; + } + return FALSE; +} - retval = KERN_SUCCESS; +boolean_t +_vm_object_lock_try(vm_object_t object) +{ + boolean_t retval; -done: + 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) +{ /* - * Cleanup. + * Called from hibernate path so check before blocking. */ - if (tmp_object != VM_OBJECT_NULL) { - vm_object_paging_end(tmp_object); - 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 (vm_object_lock_avoid(object) && ml_get_interrupts_enabled() && get_preemption_level()==0) { + mutex_pause(2); } + return _vm_object_lock_try(object); +} - if (object1_locked) { - vm_object_unlock(object1); - object1_locked = FALSE; +void +vm_object_lock_shared(vm_object_t object) +{ + if (vm_object_lock_avoid(object)) { + mutex_pause(2); } - if (object2_locked) { - vm_object_unlock(object2); - object2_locked = FALSE; + lck_rw_lock_shared(&object->Lock); +} + +boolean_t +vm_object_lock_try_shared(vm_object_t object) +{ + if (vm_object_lock_avoid(object)) { + mutex_pause(2); } - if (object1_paging) { - vm_object_lock(object1); - vm_object_paging_end(object1); - vm_object_unlock(object1); - object1_paging = FALSE; + return (lck_rw_try_lock_shared(&object->Lock)); +} + +boolean_t +vm_object_lock_upgrade(vm_object_t object) +{ boolean_t retval; + + retval = lck_rw_lock_shared_to_exclusive(&object->Lock); +#if DEVELOPMENT || DEBUG + if (retval == TRUE) + object->Lock_owner = current_thread(); +#endif + return (retval); +} + +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 (object2_paging) { - vm_object_lock(object2); - vm_object_paging_end(object2); - vm_object_unlock(object2); - object2_paging = FALSE; +#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 (wimg_mode == VM_WIMG_USE_DEFAULT) + object->set_cache_attr = FALSE; + else + object->set_cache_attr = TRUE; - return retval; + object->wimg_bits = wimg_mode; + + vm_object_change_wimg_mode_count++; } +#if CONFIG_FREEZE /* - * vm_object_build_cluster - * - * 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 - * + * 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 int speculative_reads_disabled; -uint32_t pre_heat_scaling[MAX_UPL_TRANSFER]; -uint32_t pre_heat_cluster[MAX_UPL_TRANSFER]; +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); +} -#define PRE_HEAT_MULTIPLIER 4 -__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) +void +vm_object_compressed_freezer_done() { - 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; - int sequential_run; - int sequential_behavior = VM_BEHAVIOR_SEQUENTIAL; + vm_compressor_finished_filling(&freezer_chead); +} - assert( !(*length & PAGE_MASK)); - assert( !(*start & PAGE_MASK_64)); - if ( (max_length = *length) > (MAX_UPL_TRANSFER * PAGE_SIZE) ) - max_length = (MAX_UPL_TRANSFER * PAGE_SIZE); - /* - * we'll always return a cluster size of at least - * 1 page, since the original fault must always - * be processed - */ - *length = PAGE_SIZE; +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; - if (speculative_reads_disabled || fault_info == NULL || max_length == 0) { - /* - * no cluster... just fault the page in - */ - return; - } - orig_start = *start; - target_start = orig_start; - cluster_size = round_page_32(fault_info->cluster_size); - behavior = fault_info->behavior; + assert(object != VM_OBJECT_NULL); + assert(object->internal); vm_object_lock(object); - 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 */ + if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) { + + if (!object->pager_initialized) { - object_size = round_page_64(object_size); + vm_object_collapse(object, (vm_object_offset_t) 0, TRUE); - if (orig_start >= object_size) { - /* - * fault occurred beyond the EOF... - * we need to punt w/o changing the - * starting offset - */ - goto out; + if (!object->pager_initialized) + vm_object_compressor_pager_create(object); + } + + if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) { + vm_object_unlock(object); + return; + } } - if (object->pages_used > object->pages_created) { - /* - * must have wrapped our 32 bit counters - * so reset + + if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) { + vm_object_offset_t curr_offset = 0; + + /* + * Go through the object and make sure that any + * previously compressed pages are relocated into + * a compressed segment associated with our "freezer_chead". */ - 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; - } + while (curr_offset < object->vo_size) { + + curr_offset = vm_compressor_pager_next_compressed(object->pager, curr_offset); + + if (curr_offset == (vm_object_offset_t) -1) + break; + + retval = vm_compressor_pager_relocate(object->pager, curr_offset, &freezer_chead); + + if (retval != KERN_SUCCESS) + break; + + curr_offset += PAGE_SIZE_64; + } } - switch(behavior) { - default: - behavior = VM_BEHAVIOR_DEFAULT; + /* + * 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_DEFAULT: - if (object->internal && fault_info->user_tag == VM_MEMORY_STACK) - goto out; + obj_resident_page_count_snapshot = object->resident_page_count; - if (sequential_run >= (3 * PAGE_SIZE)) { - pre_heat_size = sequential_run + PAGE_SIZE; + vm_object_activity_begin(object); - if ((behavior = sequential_behavior) == VM_BEHAVIOR_SEQUENTIAL) - look_behind = FALSE; - else - look_ahead = FALSE; - } else { - uint32_t pages_unused; + while ((obj_resident_page_count_snapshot--) && !vm_page_queue_empty(&object->memq)) { - if (object->pages_created < 32 * PRE_HEAT_MULTIPLIER) { - /* - * prime the pump - */ - pre_heat_size = PAGE_SIZE * 8 * PRE_HEAT_MULTIPLIER; - break; - } - pages_unused = object->pages_created - object->pages_used; - - if (pages_unused < (object->pages_created / 8)) { - pre_heat_size = PAGE_SIZE * 32 * PRE_HEAT_MULTIPLIER; - } else if (pages_unused < (object->pages_created / 4)) { - pre_heat_size = PAGE_SIZE * 16 * PRE_HEAT_MULTIPLIER; - } else if (pages_unused < (object->pages_created / 2)) { - pre_heat_size = PAGE_SIZE * 8 * PRE_HEAT_MULTIPLIER; + p = (vm_page_t)vm_page_queue_first(&object->memq); + + KERNEL_DEBUG(0xe0430004 | DBG_FUNC_START, object, local_freed, 0, 0, 0); + + vm_page_lockspin_queues(); + + if (p->cleaning || p->fictitious || p->busy || p->absent || p->unusual || p->error || VM_PAGE_WIRED(p)) { + + vm_page_unlock_queues(); + + 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 { - pre_heat_size = PAGE_SIZE * 4 * PRE_HEAT_MULTIPLIER; + 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); } } - break; + + if (p->dirty == FALSE && p->precious == FALSE) { + /* + * Clean and non-precious page. + */ + vm_page_unlock_queues(); + VM_PAGE_FREE(p); - case VM_BEHAVIOR_RANDOM: - if ((pre_heat_size = cluster_size) <= PAGE_SIZE) - goto out; - break; + KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 2, 0, 0); + continue; + } - case VM_BEHAVIOR_SEQUENTIAL: - if ((pre_heat_size = cluster_size) == 0) - pre_heat_size = sequential_run + PAGE_SIZE; - look_behind = FALSE; + if (p->laundry) + vm_pageout_steal_laundry(p, TRUE); - break; + vm_page_queues_remove(p, TRUE); - case VM_BEHAVIOR_RSEQNTL: - if ((pre_heat_size = cluster_size) == 0) - pre_heat_size = sequential_run + PAGE_SIZE; - look_ahead = FALSE; + vm_page_unlock_queues(); - break; - } - if (pre_heat_size > max_length) - pre_heat_size = max_length; + /* + * 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. + */ - if (behavior == VM_BEHAVIOR_DEFAULT && vm_page_free_count < vm_page_free_target) - pre_heat_size /= 2; + vm_page_queue_remove(&object->memq, p, vm_page_t, listq); + vm_page_queue_enter(&object->memq, p, vm_page_t, listq); - if (look_ahead == TRUE) { - if (look_behind == TRUE) - target_start &= ~(pre_heat_size - 1); + /* + * 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. + */ - if ((target_start + pre_heat_size) > object_size) - pre_heat_size = (vm_size_t)(trunc_page_64(object_size - target_start)); + p->busy = TRUE; - tail_size = pre_heat_size - (orig_start - target_start) - PAGE_SIZE; - } else { - if (pre_heat_size > target_start) - pre_heat_size = target_start; - tail_size = 0; - } - pre_heat_scaling[pre_heat_size / PAGE_SIZE]++; + vm_object_activity_begin(object); - if (pre_heat_size <= PAGE_SIZE) - goto out; + vm_object_unlock(object); - if (look_behind == TRUE) { - /* - * take a look at the pages before the original - * faulting offset + /* + * arg3 == FALSE tells vm_pageout_compress_page that we don't hold the object lock and the pager may not be initialized. */ - 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 + 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; - /* - * 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; + KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 0, 0, 0); + + 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: - 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) { + if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) { + + if (!object->pager_initialized) { + + vm_object_collapse(object, (vm_object_offset_t) 0, TRUE); + + if (!object->pager_initialized) + vm_object_compressor_pager_create(object); + } + + if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL) { vm_object_unlock(object); - return KERN_FAILURE; + return; } + } + +ReScan: + next = (vm_page_t)vm_page_queue_first(&object->memq); - /* 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); + 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 (ops & UPL_POP_DUMP) { - if (dst_page->pmapped == TRUE) - pmap_disconnect(dst_page->phys_page); + /* Throw to the pageout queue */ - vm_page_lock_queues(); - vm_page_free(dst_page); - vm_page_unlock_queues(); + vm_page_lockspin_queues(); + need_unlock = TRUE; - break; + if (vm_compressor_low_on_space()) { + vm_page_unlock_queues(); + break; } - if (flags) { - *flags = 0; - - /* Get the condition of flags before requested ops */ - /* are undertaken */ + 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(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; + vm_object_lock(object); + goto ReScan; } - /* 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; - } + assert(!p->fictitious); + assert(!p->busy); + assert(!p->absent); + assert(!p->unusual); + assert(!p->error); + assert(!VM_PAGE_WIRED(p)); + assert(!p->cleaning); - 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); - } - } + if (p->pmapped == TRUE) { + int refmod_state; + int pmap_options; - 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. + * 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, - int *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 (object->resident_page_count == 0) { - if (range) { - if (ops & UPL_ROP_PRESENT) - *range = 0; - else - *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; } - - 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->pmapped == TRUE) - pmap_disconnect(dst_page->phys_page); + io_upl = upl->decmp_io_upl; + assert((io_upl->flags & UPL_DECMP_REAL_IO) != 0); + io_upl_size = io_upl->size; + upl_unlock(upl); + + /* 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; - vm_page_lock_queues(); - vm_page_free(dst_page); - vm_page_unlock_queues(); + /* Now again take the lock, recheck the state and grab out the required info */ + if(!upl_try_lock(upl)) + goto out; - } else if (ops & UPL_ROP_ABSENT) - break; - } else if (ops & UPL_ROP_PRESENT) - break; + 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)); - offset += PAGE_SIZE; + /* 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; } - vm_object_unlock(object); - if (range) { - if (offset > offset_end) - offset = offset_end; - if(offset > offset_beg) - *range = offset - offset_beg; - else *range=0; + /* 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; } - return KERN_SUCCESS; -} + upl_unlock(upl); -uint32_t scan_object_collision = 0; + /* Now we have all the information needed to do the expedite */ -void -vm_object_lock(vm_object_t object) -{ - if (object == vm_pageout_scan_wants_object) { - scan_object_collision++; - mutex_pause(2); + 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 { + offset += PAGE_SIZE; + } } - lck_rw_lock_exclusive(&object->Lock); + + /* Wakeup reprioritize thread */ + IO_REPRIO_THREAD_WAKEUP(); + +out: + kfree(io_upl_reprio_info, sizeof(uint64_t) * (io_upl_size / PAGE_SIZE)); + return; } -boolean_t -vm_object_lock_try(vm_object_t object) +void +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); + upl_t upl; + upl_page_info_t *pl; + unsigned int i, num_pages; + int cur_tier; + + 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 (lck_rw_try_lock_exclusive(&object->Lock)); -} + + return; +} -void -vm_object_lock_shared(vm_object_t object) +wait_result_t +vm_page_sleep(vm_object_t o, vm_page_t m, int interruptible) { - if (object == vm_pageout_scan_wants_object) { - scan_object_collision++; - mutex_pause(2); + wait_result_t ret; + + 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); } - lck_rw_lock_shared(&object->Lock); + 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 (object == vm_pageout_scan_wants_object) { - scan_object_collision++; - 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