]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/vm/vm_object.c
xnu-4570.1.46.tar.gz
[apple/xnu.git] / osfmk / vm / vm_object.c
index 680c07f12f506ffa56905f73ce8ceebad812fcc6..a7820e3b0e330cbaae5d163378389edbd1b1a501 100644 (file)
 #include <mach/memory_object_control_server.h>
 #include <mach/vm_param.h>
 
+#include <mach/sdt.h>
+
 #include <ipc/ipc_types.h>
 #include <ipc/ipc_port.h>
 
 #include <kern/kern_types.h>
 #include <kern/assert.h>
-#include <kern/lock.h>
 #include <kern/queue.h>
 #include <kern/xpr.h>
+#include <kern/kalloc.h>
 #include <kern/zalloc.h>
 #include <kern/host.h>
 #include <kern/host_statistics.h>
 #include <kern/processor.h>
 #include <kern/misc_protos.h>
+#include <kern/policy_internal.h>
 
 #include <vm/memory_object.h>
+#include <vm/vm_compressor_pager.h>
 #include <vm/vm_fault.h>
 #include <vm/vm_map.h>
 #include <vm/vm_object.h>
 #include <vm/vm_protos.h>
 #include <vm/vm_purgeable_internal.h>
 
+#include <vm/vm_compressor.h>
+
+#if CONFIG_PHANTOM_CACHE
+#include <vm/vm_phantom_cache.h>
+#endif
+
+boolean_t vm_object_collapse_compressor_allowed = TRUE;
+
+struct vm_counters vm_counters;
+
+#if VM_OBJECT_TRACKING
+boolean_t vm_object_tracking_inited = FALSE;
+btlog_t *vm_object_tracking_btlog;
+
+void
+vm_object_tracking_init(void)
+{
+       int vm_object_tracking;
+
+       vm_object_tracking = 1;
+       PE_parse_boot_argn("vm_object_tracking", &vm_object_tracking, 
+                          sizeof (vm_object_tracking));
+
+       if (vm_object_tracking) {
+               vm_object_tracking_btlog = btlog_create(
+                       VM_OBJECT_TRACKING_NUM_RECORDS,
+                       VM_OBJECT_TRACKING_BTDEPTH,
+                       TRUE /* caller_will_remove_entries_for_element? */);
+               assert(vm_object_tracking_btlog);
+               vm_object_tracking_inited = TRUE;
+       }
+}
+#endif /* VM_OBJECT_TRACKING */
+
 /*
  *     Virtual memory objects maintain the actual data
  *     associated with allocated virtual memory.  A given
 static kern_return_t   vm_object_terminate(
                                vm_object_t     object);
 
-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,
@@ -196,17 +225,19 @@ 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);
 
-static zone_t          vm_object_zone;         /* vm backing store zone */
+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 +245,7 @@ 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
@@ -226,144 +257,85 @@ static struct vm_object                  vm_submap_object_store;
  */
 static struct vm_object                        vm_object_template;
 
-/*
- *     Virtual memory objects that are not referenced by
- *     any address maps, but that are allowed to persist
- *     (an attribute specified by the associated memory manager),
- *     are kept in a queue (vm_object_cached_list).
- *
- *     When an object from this queue is referenced again,
- *     for example to make another address space mapping,
- *     it must be removed from the queue.  That is, the
- *     queue contains *only* objects with zero references.
- *
- *     The kernel may choose to terminate objects from this
- *     queue in order to reclaim storage.  The current policy
- *     is to permit a fixed maximum number of unreferenced
- *     objects (vm_object_cached_max).
- *
- *     A spin lock (accessed by routines
- *     vm_object_cache_{lock,lock_try,unlock}) governs the
- *     object cache.  It must be held when objects are
- *     added to or removed from the cache (in vm_object_terminate).
- *     The routines that acquire a reference to a virtual
- *     memory object based on one of the memory object ports
- *     must also lock the cache.
- *
- *     Ideally, the object cache should be more isolated
- *     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 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)
+unsigned int vm_page_purged_wired = 0;
+unsigned int vm_page_purged_busy = 0;
+unsigned int vm_page_purged_others = 0;
 
-#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)
+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)
-
-#define        VM_OBJECT_HASH_COUNT            1024
-static queue_head_t    vm_object_hashtable[VM_OBJECT_HASH_COUNT];
-static struct zone             *vm_object_hash_zone;
-
-struct vm_object_hash_entry {
-       queue_chain_t           hash_link;      /* hash chain link */
-       memory_object_t pager;          /* pager we represent */
-       vm_object_t             object;         /* corresponding object */
-       boolean_t               waiting;        /* someone waiting for
-                                                * termination */
-};
+               lck_mtx_unlock(&vm_object_cached_lock_data)
 
-typedef struct vm_object_hash_entry    *vm_object_hash_entry_t;
-#define VM_OBJECT_HASH_ENTRY_NULL      ((vm_object_hash_entry_t) 0)
+static void    vm_object_cache_remove_locked(vm_object_t);
 
-#define VM_OBJECT_HASH_SHIFT   8
-#define vm_object_hash(pager) \
-       ((((unsigned)pager) >> VM_OBJECT_HASH_SHIFT) % VM_OBJECT_HASH_COUNT)
-
-void vm_object_hash_entry_free(
-       vm_object_hash_entry_t  entry);
 
 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() */
-unsigned int vm_object_reap_count = 0;
-unsigned int vm_object_reap_count_async = 0;
-
-/*
- *     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;
-
-       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);
-                       return(entry);
-               }
 
-               entry = (vm_object_hash_entry_t)queue_next(&entry->hash_link);
-       }
-
-       return(VM_OBJECT_HASH_ENTRY_NULL);
-}
-
-/*
- *     vm_object_hash_enter enters the specified
- *     pager / cache object association in the hashtable.
- */
-
-static void
-vm_object_hash_insert(
-       vm_object_hash_entry_t  entry)
-{
-       register queue_t                bucket;
+static lck_mtx_t       vm_object_reaper_lock_data;
+static lck_mtx_ext_t   vm_object_reaper_lock_data_ext;
 
-       bucket = &vm_object_hashtable[vm_object_hash(entry->pager)];
+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;
 
-       queue_enter(bucket, entry, vm_object_hash_entry_t, hash_link);
+#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);                   \
 }
 
-static vm_object_hash_entry_t
-vm_object_hash_entry_alloc(
-       memory_object_t pager)
-{
-       vm_object_hash_entry_t  entry;
-
-       entry = (vm_object_hash_entry_t)zalloc(vm_object_hash_zone);
-       entry->pager = pager;
-       entry->object = VM_OBJECT_NULL;
-       entry->waiting = FALSE;
+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
 
-       return(entry);
-}
+#if 0
+#undef KERNEL_DEBUG
+#define KERNEL_DEBUG KERNEL_DEBUG_CONSTANT
+#endif
 
-void
-vm_object_hash_entry_free(
-       vm_object_hash_entry_t  entry)
-{
-       zfree(vm_object_hash_zone, entry);
-}
 
 /*
  *     vm_object_allocate:
@@ -378,23 +350,36 @@ _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);
-       queue_init(&object->msr_q);
-#ifdef UPL_DEBUG
+       vm_page_queue_init(&object->memq);
+#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 +392,12 @@ 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 +407,80 @@ lck_attr_t        kernel_object_lck_attr;
 __private_extern__ void
 vm_object_bootstrap(void)
 {
-       register 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");
+       assert(sizeof (mo_ipc_object_bits_t) == sizeof (ipc_object_bits_t));
+
+       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);
+       zone_change(vm_object_zone, Z_ALIGNMENT_REQUIRED, 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);
 
-       vm_object_hash_zone =
-                       zinit((vm_size_t) sizeof (struct vm_object_hash_entry),
-                             round_page_32(512*1024),
-                             round_page_32(12*1024),
-                             "vm object hash entries");
+       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_COUNT; i++)
-               queue_init(&vm_object_hashtable[i]);
+       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_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;
+    // static vm_object_template is zeroed
+    // 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 */
@@ -483,14 +490,13 @@ vm_object_bootstrap(void)
        vm_object_template.pager_trusted = FALSE;
        vm_object_template.can_persist = FALSE;
        vm_object_template.internal = TRUE;
-       vm_object_template.temporary = TRUE;
        vm_object_template.private = FALSE;
        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.purgeable_only_by_kernel = FALSE;
        vm_object_template.shadowed = FALSE;
-       vm_object_template.silent_overwrite = FALSE;
-       vm_object_template.advisory_pageout = FALSE;
        vm_object_template.true_share = FALSE;
        vm_object_template.terminating = FALSE;
        vm_object_template.named = FALSE;
@@ -501,27 +507,31 @@ vm_object_bootstrap(void)
 
        vm_object_template.cached_list.prev = NULL;
        vm_object_template.cached_list.next = NULL;
-       vm_object_template.msr_q.prev = NULL;
-       vm_object_template.msr_q.next = NULL;
        
        vm_object_template.last_alloc = (vm_object_offset_t) 0;
        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.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 +540,33 @@ 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 +578,14 @@ 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;
+       kernel_object->no_tag_update = TRUE;
 
        /*
         *      Initialize the "submap object".  Make it as large as the
@@ -560,13 +593,8 @@ 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 +603,32 @@ 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");
+       zone_change(io_reprioritize_req_zone, Z_COLLECT, FALSE);
+
+       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)
@@ -590,7 +639,7 @@ vm_object_reaper_init(void)
        kr = kernel_thread_start_priority(
                (thread_continue_t) vm_object_reaper_thread,
                NULL,
-               BASEPRI_PREEMPT - 1,
+               BASEPRI_VM,
                &thread);
        if (kr != KERN_SUCCESS) {
                panic("failed to launch vm_object_reaper_thread kr=0x%x", kr);
@@ -610,22 +659,20 @@ 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);
 }
 
 
-#define        MIGHT_NOT_CACHE_SHADOWS         1
-#if    MIGHT_NOT_CACHE_SHADOWS
-static int cache_shadows = TRUE;
-#endif /* MIGHT_NOT_CACHE_SHADOWS */
-
 /*
  *     vm_object_deallocate:
  *
@@ -640,13 +687,12 @@ 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)
 {
-       boolean_t       retry_cache_trim = FALSE;
        vm_object_t     shadow = VM_OBJECT_NULL;
-       uint32_t        try_failed_count = 0;
        
 //     if(object)dbgLog(object, object->ref_count, object->can_persist, 3);    /* (TEST/DEBUG) */
 //     else dbgLog(object, 0, 0, 3);   /* (TEST/DEBUG) */
@@ -654,18 +700,38 @@ 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 +752,36 @@ 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 +796,8 @@ 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 +812,16 @@ 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 +840,6 @@ 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 +861,7 @@ vm_object_deallocate(
                                 */
                                vm_object_collapse(object, 0, FALSE);
                        }
-
                        vm_object_unlock(object); 
-                       if (retry_cache_trim &&
-                           ((object = vm_object_cache_trim(TRUE)) !=
-                            VM_OBJECT_NULL)) {
-                               continue;
-                       }
                        return;
                }
 
@@ -839,422 +876,457 @@ vm_object_deallocate(
                                              VM_OBJECT_EVENT_INITIALIZED,
                                              THREAD_UNINT);
                        vm_object_unlock(object);
-                       vm_object_cache_unlock();
+
                        thread_block(THREAD_CONTINUE_NULL);
                        continue;
                }
 
+               XPR(XPR_VM_OBJECT,
+                   "vm_o_deallocate: 0x%X res %d paging_ops %d thread 0x%p ref %d\n",
+                   object, object->resident_page_count,
+                   object->paging_in_progress,
+                   (void *)current_thread(),object->ref_count);
+
+               VM_OBJ_RES_DECR(object);        /* XXX ? */
                /*
-                *      If this object can persist, then enter it in
-                *      the cache. Otherwise, terminate it.
-                *
-                *      NOTE:  Only permanent objects are cached, and
-                *      permanent objects cannot have shadows.  This
-                *      affects the residence counting logic in a minor
-                *      way (can do it in-line, mostly).
+                *      Terminate this object. If it had a shadow,
+                *      then deallocate it; otherwise, if we need
+                *      to retry a cache trim, do so now; otherwise,
+                *      we are done. "pageout" objects have a shadow,
+                *      but maintain a "paging reference" rather than
+                *      a normal reference.
                 */
+               shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
 
-               if ((object->can_persist) && (object->alive)) {
-                       /*
-                        *      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)) {
-                                       continue;
-                               }
-                               return;
-                       }
+               if (vm_object_terminate(object) != KERN_SUCCESS) {
+                       return;
+               }
+               if (shadow != VM_OBJECT_NULL) {
+                       object = shadow;
+                       continue;
+               }
+               return;
+       }
+}
 
-#if    MIGHT_NOT_CACHE_SHADOWS
-                       /*
-                        *      Remove shadow now if we don't
-                        *      want to cache shadows.
-                        */
-                       if (! cache_shadows) {
-                               shadow = object->shadow;
-                               object->shadow = VM_OBJECT_NULL;
-                       }
-#endif /* MIGHT_NOT_CACHE_SHADOWS */
 
-                       /*
-                        *      Enter the object onto the queue of
-                        *      cached objects, and deactivate
-                        *      all of its pages.
-                        */
-                       assert(object->shadow == VM_OBJECT_NULL);
-                       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);
-
-                       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);
 
-#if    MIGHT_NOT_CACHE_SHADOWS
-                       /*
-                        *      If we have a shadow that we need
-                        *      to deallocate, do so now, remembering
-                        *      to trim the cache later.
-                        */
-                       if (! cache_shadows && shadow != VM_OBJECT_NULL) {
-                               object = shadow;
-                               retry_cache_trim = TRUE;
-                               continue;
-                       }
-#endif /* MIGHT_NOT_CACHE_SHADOWS */
+vm_page_t
+vm_object_page_grab(
+       vm_object_t     object)
+{
+       vm_page_t       p, next_p;
+       int             p_limit = 0;
+       int             p_skipped = 0;
 
-                       /*
-                        *      Trim the cache. If the cache trim
-                        *      returns with a shadow for us to deallocate,
-                        *      then remember to retry the cache trim
-                        *      when we are done deallocating the shadow.
-                        *      Otherwise, we are done.
-                        */
+       vm_object_lock_assert_exclusive(object);
 
-                       object = vm_object_cache_trim(TRUE);
-                       if (object == VM_OBJECT_NULL) {
-                               return;
-                       }
-                       retry_cache_trim = TRUE;
+       next_p = (vm_page_t)vm_page_queue_first(&object->memq);
+       p_limit = MIN(50, object->resident_page_count);
 
-               } else {
-                       /*
-                        *      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->paging_in_progress,
-                           (void *)current_thread(),object->ref_count);
+       while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next_p) && --p_limit > 0) {
 
-                       VM_OBJ_RES_DECR(object);        /* XXX ? */
-                       /*
-                        *      Terminate this object. If it had a shadow,
-                        *      then deallocate it; otherwise, if we need
-                        *      to retry a cache trim, do so now; otherwise,
-                        *      we are done. "pageout" objects have a shadow,
-                        *      but maintain a "paging reference" rather than
-                        *      a normal reference.
-                        */
-                       shadow = object->pageout?VM_OBJECT_NULL:object->shadow;
-                       if(vm_object_terminate(object) != KERN_SUCCESS) {
-                               return;
-                       }
-                       if (shadow != VM_OBJECT_NULL) {
-                               object = shadow;
-                               continue;
-                       }
-                       if (retry_cache_trim &&
-                           ((object = vm_object_cache_trim(TRUE)) !=
-                            VM_OBJECT_NULL)) {
-                               continue;
-                       }
-                       return;
-               }
-       }
-       assert(! retry_cache_trim);
-}
+               p = next_p;
+               next_p = (vm_page_t)vm_page_queue_next(&next_p->listq);
 
-/*
- *     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)
-{
-       register vm_object_t object = VM_OBJECT_NULL;
-       vm_object_t shadow;
+               if (VM_PAGE_WIRED(p) || p->busy || p->cleaning || p->laundry || p->fictitious)
+                       goto move_page_in_obj;
 
-       for (;;) {
+               if (p->pmapped || p->dirty || p->precious) {
+                       vm_page_lockspin_queues();
 
-               /*
-                *      If we no longer need to trim the cache,
-                *      then we are done.
-                */
+                       if (p->pmapped) {
+                               int refmod_state;
 
-               vm_object_cache_lock();
-               if (vm_object_cached_count <= vm_object_cached_max) {
-                       vm_object_cache_unlock();
-                       return VM_OBJECT_NULL;
-               }
+                               vm_object_page_grab_pmapped++;
 
-               /*
-                *      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);
-
-               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 (p->reference == FALSE || p->dirty == FALSE) {
 
-               /*
-                *      Since this object is in the cache, we know
-                *      that it is initialized and has no references.
-                *      Take a reference to avoid recursive deallocations.
-                */
+                                       refmod_state = pmap_get_refmod(VM_PAGE_GET_PHYS_PAGE(p));
 
-               assert(object->pager_initialized);
-               assert(object->ref_count == 0);
-               vm_object_lock_assert_exclusive(object);
-               object->ref_count++;
+                                       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) {
 
-               /*
-                *      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);
+                                       refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
+
+                                       if (refmod_state & VM_MEM_REFERENCED)
+                                               p->reference = TRUE;
+                                       if (refmod_state & VM_MEM_MODIFIED) {
+                                               SET_PAGE_DIRTY(p, FALSE);
+                                       }
+
+                                       if (p->dirty == FALSE)
+                                               goto take_page;
+                               }
+                       }
+                       if ((p->vm_page_q_state != VM_PAGE_ON_ACTIVE_Q) && p->reference == TRUE) {
+                               vm_page_activate(p);
+
+                               VM_STAT_INCR(reactivations);
+                               vm_object_page_grab_reactivations++;
                        }
+                       vm_page_unlock_queues();
+move_page_in_obj:
+                       vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+                       vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
+
+                       p_skipped++;
+                       continue;
                }
+               vm_page_lockspin_queues();
+take_page:
+               vm_page_free_prepare_queues(p);
+               vm_object_page_grab_returned++;
+               vm_object_page_grab_skipped += p_skipped;
+
+               vm_page_unlock_queues();
+
+               vm_page_free_prepare_object(p, TRUE);
+               
+               return (p);
        }
+       vm_object_page_grab_skipped += p_skipped;
+       vm_object_page_grab_failed++;
+
+       return (NULL);
 }
 
-#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 */
 
-#define V_O_T_MAX_BATCH        256
 
-/*
- *     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 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 */
+#define EVICT_PREPARE_LIMIT    64
+#define EVICT_AGE              10
 
-#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
+static clock_sec_t     vm_object_cache_aging_ts = 0;
 
+static void
+vm_object_cache_remove_locked(
+       vm_object_t     object)
+{
+       assert(object->purgable == VM_PURGABLE_DENY);
+       assert(object->wired_page_count == 0);
 
+       queue_remove(&vm_object_cached_list, object, vm_object_t, objq);
+       object->objq.next = NULL;
+       object->objq.prev = NULL;
 
-       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_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);
+       /*
+        * do a couple of quick checks to see if it's 
+        * worthwhile grabbing the lock
+        */
+       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);
+
+       /*
+        * the object on the head of the queue has not
+        * yet sufficiently aged
+        */
+       if (sec < vm_object_cache_aging_ts) {
+               KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, 0, 0, 0, 0, 0);
+               return (0);
+       }
+       /*
+        * don't need the queue lock to find 
+        * and lock an object on the cached list
+        */
+       vm_page_unlock_queues();
+
+       vm_object_cache_lock_spin();
+
+       for (;;) {
+               next_obj = (vm_object_t)queue_first(&vm_object_cached_list);
+
+               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
                         */
-                       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;
+                       break;
                }
+               vm_object_cache_unlock();
+
+               if (object == VM_OBJECT_NULL)
+                       break;
+
                /*
-                * 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 is locked at this point and
+                * has resident pages
                 */
-               object->pager_trusted = FALSE;
+               next_p = (vm_page_t)vm_page_queue_first(&object->memq);
 
-               p = (vm_page_t) queue_first(&object->memq);
+               /*
+                * break the page scan into 2 pieces to minimize the time spent
+                * behind the page queue lock...
+                * the list of pages on these unused objects is likely to be cold
+                * w/r to the cpu cache which increases the time to scan the list
+                * tenfold...  and we may have a 'run' of pages we can't utilize that
+                * needs to be skipped over...
+                */
+               if ((ep_limit = num_to_evict - (ep_freed + ep_moved)) > EVICT_PREPARE_LIMIT)
+                       ep_limit = EVICT_PREPARE_LIMIT;
+               ep_count = 0;
 
-               VM_PAGE_CHECK(p);
+               while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)next_p) && object->vo_cache_pages_to_scan && ep_count < ep_limit) {
 
-               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();
+                       p = next_p;
+                       next_p = (vm_page_t)vm_page_queue_next(&next_p->listq);
+
+                       object->vo_cache_pages_to_scan--;
+
+                       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);
+
+                               ep_skipped++;
                                continue;
-                       } else {
-                               panic("vm_object_terminate.3 %p %p", object, p);
                        }
+                       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);
+
+                               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);
 
-               p->busy = TRUE;
-               VM_PAGE_QUEUES_REMOVE(p);
-#if VM_OBJ_TERM_STATS
-               pages_removed++;
-#endif /* VM_OBJ_TERM_STATS */
+               vm_page_lockspin_queues();
 
-               if (p->absent || p->private) {
+               for (ep_index = 0; ep_index < ep_count; ep_index++) {
 
-                       /*
-                        *      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.
-                        */
+                       p = ep_array[ep_index];
 
-                       goto free_page;
-               }
+                       if (p->wpmapped || p->dirty || p->precious) {
+                               p->reference = FALSE;
+                               p->no_cache = FALSE;
 
-               if (p->fictitious) {
-                       if (p->phys_page == vm_page_guard_addr) {
-                               goto free_page;
+                               /*
+                                * we've already filtered out pages that are in the laundry
+                                * so if we get here, this page can't be on the pageout queue
+                                */
+                               vm_page_queues_remove(p, FALSE);
+                               vm_page_enqueue_inactive(p, TRUE);
+
+                               ep_moved++;
+                       } else {
+#if CONFIG_PHANTOM_CACHE
+                               vm_phantom_cache_add_ghost(p);
+#endif
+                               vm_page_free_prepare_queues(p);
+
+                               assert(p->pageq.next == 0 && p->pageq.prev == 0);
+                               /*
+                                * Add this page to our list of reclaimed pages,
+                                * to be freed later.
+                                */
+                               p->snext = local_free_q;
+                               local_free_q = p;
+
+                               ep_freed++;
                        }
-                       panic("vm_object_terminate.4 %p %p", object, p);
                }
+               vm_page_unlock_queues();
 
-               if (!p->dirty && p->wpmapped)
-                       p->dirty = pmap_is_modified(p->phys_page);
+               KERNEL_DEBUG(0x13001f4 | DBG_FUNC_END, object, object->resident_page_count, ep_freed, ep_moved, 0);
 
-               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:
+               if (local_free_q) {
+                       vm_page_free_list(local_free_q, TRUE);
+                       local_free_q = VM_PAGE_NULL;
+               }
+               if (object->vo_cache_pages_to_scan == 0) {
+                       KERNEL_DEBUG(0x1300208, object, object->resident_page_count, ep_freed, ep_moved, 0);
+
+                       vm_object_cache_remove(object);
+
+                       KERNEL_DEBUG(0x13001fc, object, object->resident_page_count, ep_freed, ep_moved, 0);
+               }
+               /*
+                * done with this object
+                */
+               vm_object_unlock(object);
+               object = VM_OBJECT_NULL;
+
+               /*
+                * at this point, we are not holding any locks
+                */
+               if ((ep_freed + ep_moved) >= num_to_evict) {
                        /*
-                        * Add this page to our list of reclaimed pages,
-                        * to be freed later.
+                        * we've reached our target for the
+                        * number of pages to evict
                         */
-                       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);
+                       break;
+               }
+               vm_object_cache_lock_spin();
        }
+       /*
+        * put the page queues lock back to the caller's
+        * idea of it 
+        */
+       vm_page_lock_queues();
+
+       vm_object_cache_pages_freed += ep_freed;
+       vm_object_cache_pages_moved += ep_moved;
+       vm_object_cache_pages_skipped += ep_skipped;
+
+       KERNEL_DEBUG(0x13001ec | DBG_FUNC_END, ep_freed, 0, 0, 0, 0);
+       return (ep_freed);
+}
+
+/*
+ *     Routine:        vm_object_terminate
+ *     Purpose:
+ *             Free all resources associated with a vm_object.
+ *     In/out conditions:
+ *             Upon entry, the object must be locked,
+ *             and the object must have exactly one reference.
+ *
+ *             The shadow object reference is left alone.
+ *
+ *             The object must be unlocked if its found that pages
+ *             must be flushed to a backing object.  If someone
+ *             manages to map the object while it is being flushed
+ *             the object is returned unlocked and unchanged.  Otherwise,
+ *             upon exit, the cache will be unlocked, and the
+ *             object will cease to exist.
+ */
+static kern_return_t
+vm_object_terminate(
+       vm_object_t     object)
+{
+       vm_object_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->internal && 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);
+       }
        /*
         *      Make sure the object isn't already being terminated
         */
-       if(object->terminating) {
+       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;
        }
@@ -1263,12 +1335,11 @@ vm_object_terminate(
         * Did somebody get a reference to the object while we were
         * cleaning it?
         */
-       if(object->ref_count != 1) {
+       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;
        }
@@ -1279,7 +1350,9 @@ vm_object_terminate(
 
        object->terminating = TRUE;
        object->alive = FALSE;
-       vm_object_remove(object);
+
+       if ( !object->internal && (object->objq.next || object->objq.prev))
+               vm_object_cache_remove(object);
 
        /*
         *      Detach the object from its shadow if we are the shadow's
@@ -1294,7 +1367,8 @@ vm_object_terminate(
                vm_object_unlock(shadow_object);
        }
 
-       if (object->paging_in_progress != 0) {
+       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
@@ -1317,7 +1391,6 @@ vm_object_terminate(
                 * VM object is "terminating" and not "alive".
                 */
                vm_object_reap_async(object);
-               vm_object_cache_unlock();
                vm_object_unlock(object);
                /*
                 * Return KERN_FAILURE to let the caller know that we
@@ -1328,13 +1401,15 @@ vm_object_terminate(
                 */
                return KERN_FAILURE;
        }
-
-       /* complete the VM object termination */
+       /*
+        * complete the VM object termination
+        */
        vm_object_reap(object);
        object = VM_OBJECT_NULL;
-       /* cache lock and object lock were released by vm_object_reap() */
 
        /*
+        * 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.
@@ -1345,48 +1420,47 @@ vm_object_terminate(
        return KERN_SUCCESS;
 }
 
+
 /*
  * 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.
+ * The VM object must be locked by caller.
+ * The lock will be released on return and the VM object is no longer valid.
  */
+
 void
 vm_object_reap(
        vm_object_t object)
 {
        memory_object_t         pager;
-       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 */
 
-#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);
+       assert(object->activity_in_progress == 0);
 
        vm_object_reap_count++;
 
-       local_free_q = VM_PAGE_NULL;
-#if VM_OBJ_TERM_STATS
-       local_free_count = 0;
-#endif /* VM_OBJ_TERM_STATS */
+       /*
+        * Disown this purgeable object to cleanup its owner's purgeable
+        * ledgers.  We need to do this before disconnecting the object
+        * from its pager, to properly account for compressed pages.
+        */
+       if (object->internal &&
+           object->purgable != VM_PURGABLE_DENY) {
+               vm_purgeable_accounting(object,
+                                       object->purgable,
+                                       TRUE); /* disown */
+       }
 
        pager = object->pager;
        object->pager = MEMORY_OBJECT_NULL;
 
        if (pager != MEMORY_OBJECT_NULL)
                memory_object_control_disable(object->pager_control);
-       vm_object_cache_unlock();
 
-       vm_object_lock_assert_exclusive(object);
        object->ref_count--;
 #if    TASK_SWAPPER
        assert(object->res_count == 0);
@@ -1394,69 +1468,95 @@ vm_object_reap(
 
        assert (object->ref_count == 0);
 
-       /* 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);
-
-               /* 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.
+        * remove from purgeable queue if it's on
         */
-       if (object->pageout) {
-               assert(object->shadow != VM_OBJECT_NULL);
+       if (object->internal) {
+               task_t owner;
 
-               vm_pageout_object_terminate(object);
+               owner = object->vo_purgeable_owner;
+
+               VM_OBJECT_UNWIRED(object);
+
+               if (object->purgable == VM_PURGABLE_DENY) {
+                       /* not purgeable: nothing to do */
+               } else if (object->purgable == VM_PURGABLE_VOLATILE) {
+                       purgeable_q_t queue;
+
+                       assert(object->vo_purgeable_owner == NULL);
 
-       } 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) {
+                       queue = vm_purgeable_object_remove(object);
+                       assert(queue);
+
+                       if (object->purgeable_when_ripe) {
                                /*
-                                * Free the pages we reclaimed so far
-                                * and take a little break to avoid
-                                * hogging the page queue lock too long
+                                * Must take page lock for this -
+                                * using it to protect token queue
                                 */
-                               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;
+                               vm_page_lock_queues();
+                               vm_purgeable_token_delete_first(queue);
+        
+                               assert(queue->debug_count_objects>=0);
+                               vm_page_unlock_queues();
                        }
-                       p = (vm_page_t) queue_first(&object->memq);
-
-                       vm_page_free_prepare(p);
 
-                       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 */
+                       /*
+                        * 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;
+               }
+               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);
+       }
+    
+       if (object->pageout) {
                /*
-                * Free the remaining reclaimed pages
+                * free all remaining pages tabled on
+                * this object
+                * clean up it's shadow
                 */
-               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->shadow != VM_OBJECT_NULL);
+
+               vm_pageout_object_terminate(object);
 
+       } else if (object->resident_page_count) {
+               /*
+                * free all remaining pages tabled on 
+                * this object
+                */
+               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);
 
        /*
@@ -1476,12 +1576,15 @@ vm_object_reap(
        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;
 
+#if VM_OBJECT_TRACKING
+       if (vm_object_tracking_inited) {
+               btlog_remove_entries_for_element(vm_object_tracking_btlog,
+                                                object);
+       }
+#endif /* VM_OBJECT_TRACKING */
+
        vm_object_lock_destroy(object);
        /*
         *      Free the space for the object.
@@ -1490,63 +1593,314 @@ vm_object_reap(
        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_object_reap_count_async++;
 
-       /* 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);
-}
+unsigned int vm_max_batch = 256;
 
-void
-vm_object_reaper_thread(void)
-{
-       vm_object_t     object, shadow_object;
+#define V_O_R_MAX_BATCH 128
 
-       vm_object_cache_lock();
+#define BATCH_LIMIT(max)       (vm_max_batch >= max ? max : vm_max_batch)
 
-       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.
-                */
-               while (object->paging_in_progress != 0) {
-                       vm_object_cache_unlock();
-                       vm_object_wait(object,
-                                      VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
-                                      THREAD_UNINT);
-                       vm_object_cache_lock();
-                       vm_object_lock(object);
-               }
 
-               shadow_object =
-                       object->pageout ? VM_OBJECT_NULL : object->shadow;
+#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
 
-               vm_object_reap(object);
-               /* cache is unlocked and object is no longer valid */
-               object = VM_OBJECT_NULL;
+
+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) {
+               /*
+                * We need to disconnect pages from all pmaps before
+                * releasing them to the free list
+                */
+               disconnect_on_release = TRUE;
+       } else {
+               /*
+                * Either the caller has already disconnected the pages
+                * from all pmaps, or we disconnect them here as we add
+                * them to out local list of pages to be released.
+                * No need to re-disconnect them when we release the pages
+                * to the free list.
+                */
+               disconnect_on_release = FALSE;
+       }
+               
+restart_after_sleep:
+       if (vm_page_queue_empty(&object->memq))
+               return;
+       loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH);
+
+       if (reap_type == REAP_PURGEABLE)
+               pmap_flush_context_init(&pmap_flush_context_storage);
+
+       vm_page_lockspin_queues();
+
+       next = (vm_page_t)vm_page_queue_first(&object->memq);
+
+       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);
+
+               if (--loop_count == 0) {
+                                       
+                       vm_page_unlock_queues();
+
+                       if (local_free_q) {
+
+                               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);
+
+                       loop_count = BATCH_LIMIT(V_O_R_MAX_BATCH);
+
+                       vm_page_lockspin_queues();
+               }
+               if (reap_type == REAP_DATA_FLUSH || reap_type == REAP_TERMINATE) {
+
+                       if (p->busy || p->cleaning) {
+
+                               vm_page_unlock_queues();
+                               /*
+                                * free the pages reclaimed so far
+                                */
+                               VM_OBJ_REAP_FREELIST(local_free_q,
+                                                    disconnect_on_release);
+
+                               PAGE_SLEEP(object, p, THREAD_UNINT);
+
+                               goto restart_after_sleep;
+                       }
+                       if (p->laundry)
+                               vm_pageout_steal_laundry(p, TRUE);
+               }
+               switch (reap_type) {
+
+               case REAP_DATA_FLUSH:
+                       if (VM_PAGE_WIRED(p)) {
+                               /*
+                                * this is an odd case... perhaps we should
+                                * zero-fill this page since we're conceptually
+                                * tossing its data at this point, but leaving
+                                * it on the object to honor the 'wire' contract
+                                */
+                               continue;
+                       }
+                       break;
+                       
+               case REAP_PURGEABLE:
+                       if (VM_PAGE_WIRED(p)) {
+                               /*
+                                * can't purge a wired page
+                                */
+                               vm_page_purged_wired++;
+                               continue;
+                       }
+                       if (p->laundry && !p->busy && !p->cleaning)
+                               vm_pageout_steal_laundry(p, TRUE);
+
+                       if (p->cleaning || p->laundry || p->absent) {
+                               /*
+                                * page is being acted upon,
+                                * so don't mess with it
+                                */
+                               vm_page_purged_others++;
+                               continue;
+                       }
+                       if (p->busy) {
+                               /*
+                                * We can't reclaim a busy page but we can
+                                * make it more likely to be paged (it's not wired) to make
+                                * sure that it gets considered by
+                                * vm_pageout_scan() later.
+                                */
+                               if (VM_PAGE_PAGEABLE(p))
+                                       vm_page_deactivate(p);
+                               vm_page_purged_busy++;
+                               continue;
+                       }
+
+                       assert(VM_PAGE_OBJECT(p) != kernel_object);
+
+                       /*
+                        * 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++;
+
+                       break;
+
+               case REAP_TERMINATE:
+                       if (p->absent || p->private) {
+                               /*
+                                *      For private pages, VM_PAGE_FREE just
+                                *      leaves the page structure around for
+                                *      its owner to clean up.  For absent
+                                *      pages, the structure is returned to
+                                *      the appropriate pool.
+                                */
+                               break;
+                       }
+                       if (p->fictitious) {
+                               assert (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));
+
+                       if ((p->dirty || p->precious) && !p->error && object->alive) {
+
+                               assert(!object->internal);
+                               
+                               p->free_when_done = TRUE;
+
+                               if (!p->laundry) {
+                                       vm_page_queues_remove(p, TRUE);
+                                       /*
+                                        * flush page... page will be freed
+                                        * upon completion of I/O
+                                        */
+                                       vm_pageout_cluster(p);
+                               }
+                               vm_page_unlock_queues();
+                               /*
+                                * free the pages reclaimed so far
+                                */
+                               VM_OBJ_REAP_FREELIST(local_free_q,
+                                                    disconnect_on_release);
+
+                               vm_object_paging_wait(object, THREAD_UNINT);
+
+                               goto restart_after_sleep;
+                       }
+                       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();
+
+       /*
+        * Free the remaining reclaimed pages
+        */
+       if (reap_type == REAP_PURGEABLE)
+               pmap_flush(&pmap_flush_context_storage);
+
+       VM_OBJ_REAP_FREELIST(local_free_q,
+                            disconnect_on_release);
+}
+
+
+void
+vm_object_reap_async(
+       vm_object_t     object)
+{
+       vm_object_lock_assert_exclusive(object);
+
+       vm_object_reaper_lock_spin();
+
+       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);
+}
+
+
+void
+vm_object_reaper_thread(void)
+{
+       vm_object_t     object, shadow_object;
+
+       vm_object_reaper_lock_spin();
+
+       while (!queue_empty(&vm_object_reaper_queue)) {
+               queue_remove_first(&vm_object_reaper_queue,
+                                  object,
+                                  vm_object_t,
+                                  cached_list);
+
+               vm_object_reaper_unlock();
+               vm_object_lock(object);
+
+               assert(object->terminating);
+               assert(!object->alive);
+               
+               /*
+                * The pageout daemon might be playing with our pages.
+                * Now that the object is dead, it won't touch any more
+                * pages, but some pages might already be on their way out.
+                * Hence, we wait until the active paging activities have
+                * ceased before we break the association with the pager
+                * itself.
+                */
+               while (object->paging_in_progress != 0 ||
+                       object->activity_in_progress != 0) {
+                       vm_object_wait(object,
+                                      VM_OBJECT_EVENT_PAGING_IN_PROGRESS,
+                                      THREAD_UNINT);
+                       vm_object_lock(object);
+               }
+
+               shadow_object =
+                       object->pageout ? VM_OBJECT_NULL : object->shadow;
+
+               vm_object_reap(object);
+               /* cache is unlocked and object is no longer valid */
+               object = VM_OBJECT_NULL;
 
                if (shadow_object != VM_OBJECT_NULL) {
                        /*
@@ -1556,53 +1910,22 @@ vm_object_reaper_thread(void)
                        vm_object_deallocate(shadow_object);
                        shadow_object = VM_OBJECT_NULL;
                }
-
-               vm_object_cache_lock();
+               vm_object_reaper_lock_spin();
        }
 
        /* 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*/
-}
-
-/*
- *     Routine:        vm_object_pager_wakeup
- *     Purpose:        Wake up anyone waiting for termination of a pager.
- */
 
-static void
-vm_object_pager_wakeup(
-       memory_object_t pager)
-{
-       vm_object_hash_entry_t  entry;
-       boolean_t               waiting = FALSE;
+       vm_object_reaper_unlock();
 
-       /*
-        *      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);
-       }
+       thread_block((thread_continue_t) vm_object_reaper_thread);
+       /*NOTREACHED*/
 }
 
 /*
  *     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(
@@ -1615,11 +1938,6 @@ vm_object_release_pager(
 
        (void) memory_object_terminate(pager);
 
-       /*
-        *      Wakeup anyone waiting for this terminate
-        */
-       vm_object_pager_wakeup(pager);
-
        /*
         *      Release reference to pager.
         */
@@ -1652,22 +1970,15 @@ vm_object_destroy(
         *      the destroy call.]
         */
 
-       vm_object_cache_lock();
        vm_object_lock(object);
        object->can_persist = FALSE;
        object->named = FALSE;
        object->alive = FALSE;
 
-       /*
-        *      Rip out the pager from the vm_object now...
-        */
-
-       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();
 
        /*
         * Wait for the existing paging activity (that got
@@ -1696,172 +2007,577 @@ vm_object_destroy(
        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
+ * 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.
  *
- *     Deactivate all pages in the specified object.  (Keep its pages
- *     in memory even though it is no longer referenced.)
+ * 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.
  *
- *     The object must be locked.
+ * 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.
  */
-static void
-vm_object_deactivate_all_pages(
-       register vm_object_t    object)
-{
-       register vm_page_t      p;
-       int                     loop_count;
-#if VM_OBJ_DEACT_ALL_STATS
-       int                     pages_count;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
-#define V_O_D_A_P_MAX_BATCH    256
-
-       loop_count = V_O_D_A_P_MAX_BATCH;
-#if VM_OBJ_DEACT_ALL_STATS
-       pages_count = 0;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
-       vm_page_lock_queues();
-       queue_iterate(&object->memq, p, vm_page_t, listq) {
-               if (--loop_count == 0) {
-#if VM_OBJ_DEACT_ALL_STATS
-                       hw_atomic_add(&vm_object_deactivate_all_pages_batches,
-                                     1);
-                       hw_atomic_add(&vm_object_deactivate_all_pages_pages,
-                                     pages_count);
-                       pages_count = 0;
-#endif /* VM_OBJ_DEACT_ALL_STATS */
-                       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();
-}
 
-__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;
+#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.                 */
 
-       /*
-        * entered with object lock held, acquire a paging reference to
-        * prevent the memory_object and control ports from
-        * being destroyed.
-        */
-       orig_object = object;
+#define CHUNK_SIZE     (PAGES_IN_A_CHUNK * PAGE_SIZE_64)       /* Size of a chunk in bytes */
 
-       for (;;) {
-               register vm_page_t      m;
-               vm_object_offset_t      toffset;
-               vm_object_size_t        tsize;
+typedef uint64_t       chunk_state_t;
 
-               vm_object_paging_begin(object);
-               vm_page_lock_queues();
+/*
+ * The bit map uses negative logic, so we start out with all 64 bits set to indicate
+ * that no pages have been processed yet.  Also, if len is less than the full CHUNK_SIZE,
+ * then we mark pages beyond the len as having been "processed" so that we don't waste time
+ * looking at pages in that range.  This can save us from unnecessarily chasing down the 
+ * shadow chain.
+ */
 
-               for (tsize = size, toffset = offset; tsize; tsize -= PAGE_SIZE, toffset += PAGE_SIZE) {
+#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
 
-                       if ((m = vm_page_lookup(object, toffset)) != VM_PAGE_NULL) {
 
-                               pages_found++;
+/*
+ * Return true if all pages in the chunk have not yet been processed.
+ */
 
-                               if ((m->wire_count == 0) && (!m->private) && (!m->gobbled) && (!m->busy)) {
+#define CHUNK_NOT_COMPLETE(c)  ((c) != 0)
 
-                                       assert(!m->laundry);
+/*
+ * 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.
+ */
 
-                                       m->reference = FALSE;
-                                       pmap_clear_reference(m->phys_page);
+#define PAGE_ALREADY_HANDLED(c, p)     (((c) & (1LL << (p))) == 0)
 
-                                       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 */
-                                       }
+/*
+ * Mark the page at offset 'p' in the bit map as having been processed.
+ */
 
-                                       if (!m->throttled) {
-                                               VM_PAGE_QUEUES_REMOVE(m);
+#define MARK_PAGE_HANDLED(c, p) \
+MACRO_BEGIN \
+       (c) = (c) & ~(1LL << (p)); \
+MACRO_END
 
-                                               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);
-                                               }
 
-                                               m->inactive = TRUE;
-                                               if (!m->fictitious) {
-                                                       vm_page_inactive_count++;
-                                                       token_new_pagecount++;
-                                               } else {
-                                                       assert(m->phys_page == vm_page_fictitious_addr);
-                                               }
+/*
+ * Return true if the page at the given offset has been paged out.  Object is
+ * locked upon entry and returned locked.
+ */
 
-                                               pages_moved++;
-                                       }
-                               }
-                       }
+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;
                }
-               vm_page_unlock_queues();
-               vm_object_paging_end(object);
+       }
+       return FALSE;
+}
 
-               if (object->shadow) {
-                       vm_object_t     tmp_object;
 
-                       kill_page = 0;
 
-                       offset += object->shadow_offset;
+/*
+ * 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 */
 
-                       tmp_object = object->shadow;
-                       vm_object_lock(tmp_object);
+/*
+ * Deactivate the pages in the specified object and range.  If kill_page is set, also discard any
+ * page modified state from the pmap.  Update the chunk_state as we go along.  The caller must specify
+ * a size that is less than or equal to the CHUNK_SIZE.
+ */
 
-                       if (object != orig_object)
-                               vm_object_unlock(object);
-                       object = tmp_object;
-               } else
-                       break;
-       }
-       if (object != orig_object)
-               vm_object_unlock(object);
-}
+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;
 
-/*
- *     Routine:        vm_object_pmap_protect
- *
- *     Purpose:
+       /*
+        * 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) && (!m->cleaning) && !(m->free_when_done)) {
+                               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;
+                               
+                               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);
+
+                               /*
+                                * 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.
+                                */
+
+                               if ((kill_page) && (object->internal)) {
+
+                                       VM_COMPRESSOR_PAGER_STATE_CLR(object, offset);
+
+                                       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);
+                                       }
+                               }
+                       }
+               }
+       }
+
+       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);
+}
+
+
+/*
+ * 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.
+ */
+
+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;
+
+
+       /*
+        * Get set to do a chunk.  We'll do up to CHUNK_SIZE, but no more than the
+        * remaining size the caller asked for.
+        */
+
+       length = MIN(size, CHUNK_SIZE);
+
+       /*
+        * The chunk_state keeps track of which pages we've already processed if there's
+        * a shadow chain on this object.  At this point, we haven't done anything with this
+        * range of pages yet, so initialize the state to indicate no pages processed yet.
+        */
+
+       CHUNK_INIT(chunk_state, length);
+       object = orig_object;
+
+       /*
+        * 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.
+        */
+
+       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);
+
+               /*
+                * 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.
+                */
+
+               tmp_object = object->shadow;
+
+               if (tmp_object) {
+                       kill_page = FALSE;
+                       reusable_page = FALSE;
+                       all_reusable = FALSE;
+                       offset += object->vo_shadow_offset;
+                       vm_object_lock(tmp_object);
+               }
+
+               if (object != orig_object)
+                       vm_object_unlock(object);
+
+               object = tmp_object;
+       }
+
+       if (object && object != orig_object)
+               vm_object_unlock(object);
+
+       return length;
+}
+
+
+
+/*
+ * 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__ void
+vm_object_deactivate_pages(
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       vm_object_size_t        size,
+       boolean_t               kill_page,
+       boolean_t               reusable_page,
+       struct pmap             *pmap,
+       vm_map_offset_t         pmap_offset)
+{
+       vm_object_size_t        length;
+       boolean_t               all_reusable;
+       pmap_flush_context      pmap_flush_context_storage;
+
+       /*
+        * 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.
+        */
+
+
+       all_reusable = FALSE;
+#if 11
+       /*
+        * 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
+
+       if ((reusable_page || all_reusable) && object->all_reusable) {
+               /* This means MADV_FREE_REUSABLE has been called twice, which 
+                * is probably illegal. */
+               return;
+       }
+
+       pmap_flush_context_init(&pmap_flush_context_storage);
+
+       while (size) {
+               length = deactivate_a_chunk(object, offset, size, kill_page, reusable_page, all_reusable, &pmap_flush_context_storage, pmap, pmap_offset);
+
+               size -= length;
+               offset += length;
+               pmap_offset += length;
+       }
+       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++;
+               }
+       } else if (reusable_page) {
+               vm_page_stats_reusable.partial_reusable_calls++;
+       }
+}
+
+void
+vm_object_reuse_pages(
+       vm_object_t             object,
+       vm_object_offset_t      start_offset,
+       vm_object_offset_t      end_offset,
+       boolean_t               allow_partial_reuse)
+{
+       vm_object_offset_t      cur_offset;
+       vm_page_t               m;
+       unsigned int            reused, reusable;
+
+#define VM_OBJECT_REUSE_PAGE(object, m, reused)                                \
+       MACRO_BEGIN                                                     \
+               if ((m) != VM_PAGE_NULL &&                              \
+                   (m)->reusable) {                                    \
+                       assert((object)->reusable_page_count <=         \
+                              (object)->resident_page_count);          \
+                       assert((object)->reusable_page_count > 0);      \
+                       (object)->reusable_page_count--;                \
+                       (m)->reusable = FALSE;                          \
+                       (reused)++;                                     \
+                       /*                                              \
+                        * 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
+
+       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);
+               }
+       }
+
+       /* update global stats */
+       OSAddAtomic(reusable-reused, &vm_page_stats_reusable.reusable_count);
+       vm_page_stats_reusable.reused += reused;
+       vm_page_stats_reusable.reusable += reusable;
+}
+
+/*
+ *     Routine:        vm_object_pmap_protect
+ *
+ *     Purpose:
  *             Reduces the permission for all physical
  *             pages in the specified object range.
  *
@@ -1875,7 +2591,7 @@ vm_object_deactivate_pages(
  *             remove access to all pages in shadowed objects.
  *
  *             The object must *not* be locked.  The object must
- *             be temporary/internal.  
+ *             be internal.  
  *
  *              If pmap is not NULL, this routine assumes that
  *              the only mappings for the pages are in that
@@ -1884,15 +2600,32 @@ vm_object_deactivate_pages(
 
 __private_extern__ void
 vm_object_pmap_protect(
-       register vm_object_t            object,
-       register vm_object_offset_t     offset,
+       vm_object_t                     object,
+       vm_object_offset_t              offset,
        vm_object_size_t                size,
        pmap_t                          pmap,
        vm_map_offset_t                 pmap_start,
        vm_prot_t                       prot)
 {
+       vm_object_pmap_protect_options(object, offset, size,
+                                      pmap, pmap_start, prot, 0);
+}
+
+__private_extern__ void
+vm_object_pmap_protect_options(
+       vm_object_t                     object,
+       vm_object_offset_t              offset,
+       vm_object_size_t                size,
+       pmap_t                          pmap,
+       vm_map_offset_t                 pmap_start,
+       vm_prot_t                       prot,
+       int                             options)
+{
+       pmap_flush_context      pmap_flush_context_storage;
+       boolean_t               delayed_pmap_flush = FALSE;
+
        if (object == VM_OBJECT_NULL)
-           return;
+               return;
        size = vm_object_round_page(size);
        offset = vm_object_trunc_page(offset);
 
@@ -1901,21 +2634,36 @@ vm_object_pmap_protect(
        if (object->phys_contiguous) {
                if (pmap != NULL) {
                        vm_object_unlock(object);
-                       pmap_protect(pmap, pmap_start, pmap_start + size, prot);
+                       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->shadow_offset + offset;
+                       phys_start = object->vo_shadow_offset + offset;
                        phys_end = phys_start + size;
                        assert(phys_start <= phys_end);
-                       assert(phys_end <= object->shadow_offset + object->size);
+                       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(phys_addr >> PAGE_SHIFT, prot);
+                               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;
        }
@@ -1925,38 +2673,49 @@ vm_object_pmap_protect(
        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);
+               pmap_protect_options(pmap, pmap_start, pmap_start + size, prot,
+                                    options & ~PMAP_OPTIONS_NOFLUSH, NULL);
                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 */
+          pmap_flush_context_init(&pmap_flush_context_storage);
+          delayed_pmap_flush = FALSE;
+
+           /*
+            * 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;
 
-               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;
-
-                       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)) {
-
-                       pmap_page_protect(p->phys_page, prot);
-                   }
-                 }
+               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;
+                       }
                }
+
           } else {
                vm_page_t               p;
                vm_object_offset_t      end;
@@ -1964,40 +2723,47 @@ vm_object_pmap_protect(
 
                end = offset + size;
 
-               if (pmap != PMAP_NULL) {
-                       for(target_off = offset; 
-                           target_off < end;
-                           target_off += PAGE_SIZE) {
-                               p = vm_page_lookup(object, target_off);
-                               if (p != VM_PAGE_NULL) {
-                                       vm_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);
-                               }
+               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.
                 */
-               register vm_object_t    next_object;
+               vm_object_t     next_object;
 
                next_object = object->shadow;
                if (next_object != VM_OBJECT_NULL) {
-                   offset += object->shadow_offset;
+                   offset += object->vo_shadow_offset;
                    vm_object_lock(next_object);
                    vm_object_unlock(object);
                    object = next_object;
@@ -2053,7 +2819,7 @@ vm_object_pmap_protect(
  */
 __private_extern__ kern_return_t
 vm_object_copy_slowly(
-       register vm_object_t    src_object,
+       vm_object_t             src_object,
        vm_object_offset_t      src_offset,
        vm_object_size_t        size,
        boolean_t               interruptible,
@@ -2096,10 +2862,16 @@ vm_object_copy_slowly(
 
        fault_info.interruptible = interruptible;
        fault_info.behavior  = VM_BEHAVIOR_SEQUENTIAL;
-       fault_info.user_tag  = 0;
+       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;
 
        for ( ;
            size != 0 ;
@@ -2130,110 +2902,151 @@ vm_object_copy_slowly(
                        vm_prot_t       prot = VM_PROT_READ;
                        vm_page_t       _result_page;
                        vm_page_t       top_page;
-                       register
                        vm_page_t       result_page;
                        kern_return_t   error_code;
+                       vm_object_t     result_page_object;
+
 
                        vm_object_lock(src_object);
+
+                       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;
+                       }
+
                        vm_object_paging_begin(src_object);
 
-                       fault_info.cluster_size = size;
+                       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);
+                       }
 
                        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);
 
                        switch(result) {
-                               case VM_FAULT_SUCCESS:
-                                       result_page = _result_page;
+                       case VM_FAULT_SUCCESS:
+                               result_page = _result_page;
+                               result_page_object = VM_PAGE_OBJECT(result_page);
 
-                                       /*
-                                        *      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.
-                                        */
+                               /*
+                                *      Copy the page to the new object.
+                                *
+                                *      POLICY DECISION:
+                                *              If result_page is clean,
+                                *              we could steal it instead
+                                *              of copying.
+                                */
 
-                                       vm_object_unlock(result_page->object);
-                                       vm_page_copy(result_page, new_page);
+                               vm_page_copy(result_page, new_page);
+                               vm_object_unlock(result_page_object);
 
-                                       /*
-                                        *      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();
+                               /*
+                                *      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);
 
-                                       /*
-                                        *      Release paging references and
-                                        *      top-level placeholder page, if any.
-                                        */
+                               vm_object_lock(result_page_object);
+                               PAGE_WAKEUP_DONE(result_page);
+
+                               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();
 
-                                       vm_fault_cleanup(result_page->object,
-                                                       top_page);
+                               /*
+                                *      Release paging references and
+                                *      top-level placeholder page, if any.
+                                */
 
-                                       break;
+                               vm_fault_cleanup(result_page_object,
+                                                top_page);
+
+                               break;
                                
-                               case VM_FAULT_RETRY:
-                                       break;
+                       case VM_FAULT_RETRY:
+                               break;
 
-                               case VM_FAULT_FICTITIOUS_SHORTAGE:
-                                       vm_page_more_fictitious();
+                       case VM_FAULT_MEMORY_SHORTAGE:
+                               if (vm_page_wait(interruptible))
                                        break;
+                               /* fall thru */
 
-                               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_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);
+                       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]
+                                */
 
-                               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_page_lock_queues();
-                                       vm_page_free(new_page);
-                                       vm_page_unlock_queues();
+                               vm_object_deallocate(new_object);
+                               vm_object_deallocate(src_object);
+                               *_result_object = VM_OBJECT_NULL;
+                               return(error_code ? error_code:
+                                      KERN_MEMORY_ERROR);
 
-                                       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);
        }
@@ -2421,8 +3234,8 @@ Retry:
                vm_object_lock(src_object);
                goto Retry;
        }
-       if (copy->size < src_offset+size)
-               copy->size = src_offset+size;
+       if (copy->vo_size < src_offset+size)
+               copy->vo_size = src_offset+size;
 
        if (!copy->pager_ready)
                check_ready = TRUE;
@@ -2476,6 +3289,8 @@ vm_object_copy_delayed(
        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;
 
 
        int collisions = 0;
@@ -2518,17 +3333,20 @@ vm_object_copy_delayed(
         *      the original object must be done carefully, to avoid deadlock.
         */
 
+       copy_size = vm_object_round_page(copy_size);
  Retry:
  
        /*
         * Wait for paging in progress.
         */
-       if (!src_object->true_share && src_object->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);
        }
@@ -2586,7 +3404,7 @@ vm_object_copy_delayed(
                         *      needed).
                         */
 
-                       if (old_copy->size < copy_size) {
+                       if (old_copy->vo_size < copy_size) {
                                if (src_object_shared == TRUE) {
                                        vm_object_unlock(old_copy);
                                        vm_object_unlock(src_object);
@@ -2604,11 +3422,14 @@ vm_object_copy_delayed(
                                 */
                                copy_delayed_protect_iterate++;
 
-                               queue_iterate(&src_object->memq, p, vm_page_t, listq) {
+                               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->size && 
+                                           p->offset >= old_copy->vo_size && 
                                            p->offset < copy_size) {
-                                               if (p->wire_count > 0) {
+                                               if (VM_PAGE_WIRED(p)) {
                                                        vm_object_unlock(old_copy);
                                                        vm_object_unlock(src_object);
 
@@ -2616,15 +3437,21 @@ vm_object_copy_delayed(
                                                                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(p->phys_page, 
-                                                                         (VM_PROT_ALL & ~VM_PROT_WRITE));
+                                                       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;
                                                }
                                        }
                                }
-                               old_copy->size = copy_size;
+                               if (delayed_pmap_flush == TRUE)
+                                       pmap_flush(&pmap_flush_context_storage);
+
+                               old_copy->vo_size = copy_size;
                        }
                        if (src_object_shared == TRUE)
                                vm_object_reference_shared(old_copy);
@@ -2647,8 +3474,8 @@ vm_object_copy_delayed(
                 * 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 (old_copy->vo_size > copy_size)
+                       copy_size = old_copy->vo_size;
 
                if (new_copy == VM_OBJECT_NULL) {
                        vm_object_unlock(old_copy);
@@ -2660,7 +3487,7 @@ vm_object_copy_delayed(
                        src_object_shared = FALSE;
                        goto Retry;
                }
-               new_copy->size = copy_size;     
+               new_copy->vo_size = copy_size;  
 
                /*
                 *      The copy-object is always made large enough to
@@ -2670,7 +3497,7 @@ vm_object_copy_delayed(
                 */
 
                assert((old_copy->shadow == src_object) &&
-                   (old_copy->shadow_offset == (vm_object_offset_t) 0));
+                   (old_copy->vo_shadow_offset == (vm_object_offset_t) 0));
 
        } else if (new_copy == VM_OBJECT_NULL) {
                vm_object_unlock(src_object);
@@ -2695,21 +3522,32 @@ vm_object_copy_delayed(
         */
        copy_delayed_protect_iterate++;
 
-       queue_iterate(&src_object->memq, p, vm_page_t, listq) {
+       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 < copy_size) {
-                       if (p->wire_count > 0) {
+                       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);
+
+                               if (delayed_pmap_flush == TRUE)
+                                       pmap_flush(&pmap_flush_context_storage);
+
                                return VM_OBJECT_NULL;
                        } else {
-                               pmap_page_protect(p->phys_page, 
-                                                 (VM_PROT_ALL & ~VM_PROT_WRITE));
+                               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);
+
        if (old_copy != VM_OBJECT_NULL) {
                /*
                 *      Make the old copy-object shadow the new one.
@@ -2742,7 +3580,7 @@ vm_object_copy_delayed(
         */
        vm_object_lock_assert_exclusive(new_copy);
        new_copy->shadow = src_object;
-       new_copy->shadow_offset = 0;
+       new_copy->vo_shadow_offset = 0;
        new_copy->shadowed = TRUE;      /* caller must set needs_copy */
 
        vm_object_lock_assert_exclusive(src_object);
@@ -2753,7 +3591,7 @@ vm_object_copy_delayed(
 
        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);
+               new_copy, src_object, 0, 0, 0);
 
        return new_copy;
 }
@@ -2768,7 +3606,7 @@ vm_object_copy_delayed(
  */
 __private_extern__ kern_return_t
 vm_object_copy_strategically(
-       register vm_object_t    src_object,
+       vm_object_t             src_object,
        vm_object_offset_t      src_offset,
        vm_object_size_t        size,
        vm_object_t             *dst_object,    /* OUT */
@@ -2852,7 +3690,7 @@ vm_object_copy_strategically(
                break;
 
            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);
+               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;
@@ -2874,7 +3712,7 @@ vm_object_copy_strategically(
  *     The new object and offset into that object
  *     are returned in the source parameters.
  */
-boolean_t vm_object_shadow_check = FALSE;
+boolean_t vm_object_shadow_check = TRUE;
 
 __private_extern__ boolean_t
 vm_object_shadow(
@@ -2882,10 +3720,14 @@ vm_object_shadow(
        vm_object_offset_t      *offset,        /* IN/OUT */
        vm_object_size_t        length)
 {
-       register vm_object_t    source;
-       register vm_object_t    result;
+       vm_object_t     source;
+       vm_object_t     result;
 
        source = *object;
+       assert(source != VM_OBJECT_NULL);
+       if (source == VM_OBJECT_NULL)
+               return FALSE;
+
 #if 0
        /*
         * XXX FBDP
@@ -2905,14 +3747,36 @@ vm_object_shadow(
 
        /*
         *      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).
         */
 
-       if (vm_object_shadow_check && source->ref_count == 1 &&
+       assert(source->copy_strategy != MEMORY_OBJECT_COPY_NONE); /* Purgeable objects shouldn't have shadow objects. */
+
+       if (vm_object_shadow_check &&
+           source->vo_size == length &&
+           source->ref_count == 1 &&
            (source->shadow == VM_OBJECT_NULL ||
-            source->shadow->copy == VM_OBJECT_NULL))
+            source->shadow->copy == VM_OBJECT_NULL) )
        {
-               source->shadowed = FALSE;
-               return FALSE;
+               /* 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);
        }
 
        /*
@@ -2936,7 +3800,7 @@ vm_object_shadow(
         *      and fix up the offset into the new object.
         */
 
-       result->shadow_offset = *offset;
+       result->vo_shadow_offset = *offset;
 
        /*
         *      Return the new things
@@ -2952,7 +3816,7 @@ vm_object_shadow(
  *     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
+ *  for external pagers and vm_object_compressor_pager_create for internal
  *  objects as follows:
  *
  *             pager:  the memory_object itself, supplied by
@@ -3006,10 +3870,6 @@ vm_object_shadow(
  *     [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_cache_lock
- *     governs the associations.  References gained through the
- *     association require use of the cache 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
@@ -3028,212 +3888,89 @@ vm_object_shadow(
 
 
 /*
- *     Routine:        vm_object_enter
+ *     Routine:        vm_object_memory_object_associate
  *     Purpose:
- *             Find a VM object corresponding to the given
- *             pager; if no such object exists, create one,
- *             and initialize the pager.
+ *             Associate a VM object to the given pager.
+ *             If a VM object is not provided, create one.
+ *             Initialize the pager.
  */
 vm_object_t
-vm_object_enter(
+vm_object_memory_object_associate(
        memory_object_t         pager,
+       vm_object_t             object,
        vm_object_size_t        size,
-       boolean_t               internal,
-       boolean_t               init,
        boolean_t               named)
 {
-       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;
+       memory_object_control_t control;
 
-       if (pager == MEMORY_OBJECT_NULL)
-               return(vm_object_allocate(size));
+       assert(pager != MEMORY_OBJECT_NULL);
 
-       new_object = VM_OBJECT_NULL;
-       new_entry = VM_OBJECT_HASH_ENTRY_NULL;
-       must_init = init;
+       if (object != VM_OBJECT_NULL) {
+               assert(object->internal);
+               assert(object->pager_created);
+               assert(!object->pager_initialized);
+               assert(!object->pager_ready);
+       } else {
+               object = vm_object_allocate(size);
+               assert(object != VM_OBJECT_NULL);
+               object->internal = FALSE;
+               object->pager_trusted = FALSE;
+               /* copy strategy invalid until set by memory manager */
+               object->copy_strategy = MEMORY_OBJECT_COPY_INVALID;
+       }
 
        /*
-        *      Look for an object associated with this port.
+        *      Allocate request port.
         */
-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);
-
-       object = entry->object;
-       assert(object != VM_OBJECT_NULL);
-
-       if (!must_init) {
-               if (!vm_object_lock_try(object)) {
-
-                       vm_object_cache_unlock();
-
-                       try_failed_count++;
-                       mutex_pause(try_failed_count);  /* wait a bit */
-
-                       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);
-
-               VM_STAT_INCR(hits);
-       } 
-       assert(object->ref_count > 0);
 
-       VM_STAT_INCR(lookups);
+       control = memory_object_control_allocate(object);
+       assert (control != MEMORY_OBJECT_CONTROL_NULL);
 
-       vm_object_cache_unlock();
+       vm_object_lock(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);
+       assert(!object->pager_ready);
+       assert(!object->pager_initialized);
+       assert(object->pager == NULL);
+       assert(object->pager_control == NULL);
 
        /*
-        *      If we raced to create a vm_object but lost, let's
-        *      throw away ours.
+        *      Copy the reference we were given.
         */
 
-       if (new_object != VM_OBJECT_NULL)
-               vm_object_deallocate(new_object);
-
-       if (new_entry != VM_OBJECT_HASH_ENTRY_NULL)
-               vm_object_hash_entry_free(new_entry);
-
-       if (must_init) {
-               memory_object_control_t control;
-
-               /*
-                *      Allocate request port.
-                */
-
-               control = memory_object_control_allocate(object);
-               assert (control != MEMORY_OBJECT_CONTROL_NULL);
-
-               vm_object_lock(object);
-               assert(object != kernel_object);
-
-               /*
-                *      Copy the reference we were given.
-                */
-
-               memory_object_reference(pager);
-               object->pager_created = TRUE;
-               object->pager = pager;
-               object->internal = internal;
-               object->pager_trusted = internal;
-               if (!internal) {
-                       /* copy strategy invalid until set by memory manager */
-                       object->copy_strategy = MEMORY_OBJECT_COPY_INVALID;
-               }
-               object->pager_control = control;
-               object->pager_ready = FALSE;
-
-               vm_object_unlock(object);
-
-               /*
-                *      Let the pager know we're using it.
-                */
-
-               (void) memory_object_init(pager,
-                       object->pager_control,
-                       PAGE_SIZE);
-
-               vm_object_lock(object);
-               if (named)
-                       object->named = TRUE;
-               if (internal) {
-                       object->pager_ready = TRUE;
-                       vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY);
-               }
+       memory_object_reference(pager);
+       object->pager_created = TRUE;
+       object->pager = pager;
+       object->pager_control = control;
+       object->pager_ready = FALSE;
 
-               object->pager_initialized = TRUE;
-               vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED);
-       } else {
-               vm_object_lock(object);
-       }
+       vm_object_unlock(object);
 
        /*
-        *      [At this point, the object must be locked]
+        *      Let the pager know we're using it.
         */
 
-       /*
-        *      Wait for the work above to be done by the first
-        *      thread to map this object.
-        */
+       (void) memory_object_init(pager,
+                                 object->pager_control,
+                                 PAGE_SIZE);
 
-       while (!object->pager_initialized) {
-               vm_object_sleep(object,
-                               VM_OBJECT_EVENT_INITIALIZED,
-                               THREAD_UNINT);
+       vm_object_lock(object);
+       if (named)
+               object->named = TRUE;
+       if (object->internal) {
+               object->pager_ready = TRUE;
+               vm_object_wakeup(object, VM_OBJECT_EVENT_PAGER_READY);
        }
+
+       object->pager_initialized = TRUE;
+       vm_object_wakeup(object, VM_OBJECT_EVENT_INITIALIZED);
+
        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);
+       return object;
 }
 
 /*
- *     Routine:        vm_object_pager_create
+ *     Routine:        vm_object_compressor_pager_create
  *     Purpose:
  *             Create a memory object for an internal object.
  *     In/out conditions:
@@ -3241,30 +3978,20 @@ Retry:
  *             it may be unlocked within this call.
  *     Limitations:
  *             Only one thread may be performing a
- *             vm_object_pager_create on an object at
+ *             vm_object_compressor_pager_create on an object at
  *             a time.  Presumably, only the pageout
  *             daemon will be using this routine.
  */
 
 void
-vm_object_pager_create(
-       register vm_object_t    object)
+vm_object_compressor_pager_create(
+       vm_object_t     object)
 {
        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 */
-
-       XPR(XPR_VM_OBJECT, "vm_object_pager_create, object 0x%X\n",
-               (integer_t)object, 0,0,0,0);
+       vm_object_t             pager_object = VM_OBJECT_NULL;
 
        assert(object != kernel_object);
 
-       if (memory_manager_default_check() != KERN_SUCCESS)
-               return;
-
        /*
         *      Prevent collapse or termination by holding a paging reference
         */
@@ -3284,6 +4011,19 @@ vm_object_pager_create(
                return;
        }
 
+       if ((uint32_t) (object->vo_size/PAGE_SIZE) !=
+           (object->vo_size/PAGE_SIZE)) {
+#if DEVELOPMENT || DEBUG
+               printf("vm_object_compressor_pager_create(%p): "
+                      "object size 0x%llx >= 0x%llx\n",
+                      object,
+                      (uint64_t) object->vo_size,
+                      0x0FFFFFFFFULL*PAGE_SIZE);
+#endif /* DEVELOPMENT || DEBUG */
+               vm_object_paging_end(object);
+               return;
+       }
+
        /*
         *      Indicate that a memory object has been assigned
         *      before dropping the lock, to prevent a race.
@@ -3292,18 +4032,7 @@ vm_object_pager_create(
        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.
@@ -3313,35 +4042,32 @@ vm_object_pager_create(
         *      user will ever map this object.
         */
        {
-               memory_object_default_t         dmm;
-
-               /* acquire a reference for the default memory manager */
-               dmm = memory_manager_default_reference();
-
-               assert(object->temporary);
-
                /* create our new memory object */
-               (void) memory_object_create(dmm, object->size, &pager);
-
-               memory_object_default_deallocate(dmm);
+               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_cache_lock();
-       vm_object_hash_insert(entry);
-
-       entry->object = object;
-       vm_object_cache_unlock();
-
        /*
         *      A reference was returned by
         *      memory_object_create(), and it is
-        *      copied by vm_object_enter().
+        *      copied by vm_object_memory_object_associate().
         */
 
-       if (vm_object_enter(pager, object->size, TRUE, TRUE, FALSE) != object)
-               panic("vm_object_pager_create: mismatch");
+       pager_object = vm_object_memory_object_associate(pager,
+                                                        object,
+                                                        object->vo_size,
+                                                        FALSE);
+       if (pager_object != object) {
+               panic("vm_object_compressor_pager_create: mismatch (pager: %p, pager_object: %p, orig_object: %p, orig_object size: 0x%llx)\n", pager, pager_object, object, (uint64_t) object->vo_size);
+       }
 
        /*
         *      Drop the reference we were passed.
@@ -3356,30 +4082,6 @@ vm_object_pager_create(
        vm_object_paging_end(object);
 }
 
-/*
- *     Routine:        vm_object_remove
- *     Purpose:
- *             Eliminate the pager/object association
- *             for this pager.
- *     Conditions:
- *             The object cache must be locked.
- */
-__private_extern__ void
-vm_object_remove(
-       vm_object_t     object)
-{
-       memory_object_t pager;
-
-       if ((pager = object->pager) != MEMORY_OBJECT_NULL) {
-               vm_object_hash_entry_t  entry;
-
-               entry = vm_object_hash_lookup(pager, FALSE);
-               if (entry != VM_OBJECT_HASH_ENTRY_NULL)
-                       entry->object = VM_OBJECT_NULL;
-       }
-
-}
-
 /*
  *     Global variables for vm_object_collapse():
  *
@@ -3392,12 +4094,82 @@ static long     object_bypasses  = 0;
 static boolean_t       vm_object_collapse_allowed = TRUE;
 static boolean_t       vm_object_bypass_allowed = TRUE;
 
-#if MACH_PAGEMAP
-static int     vm_external_discarded;
-static int     vm_external_collapsed;
-#endif
+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;
+
+       vm_counters.do_collapse_compressor++;
+
+       vm_object_lock_assert_exclusive(object);
+       vm_object_lock_assert_exclusive(backing_object);
+
+       size = object->vo_size;
+
+       /*
+        *      Move all compressed pages from backing_object
+        *      to the parent.
+        */
+
+       for (backing_offset = object->vo_shadow_offset;
+            backing_offset < object->vo_shadow_offset + object->vo_size;
+            backing_offset += PAGE_SIZE) {
+               memory_object_offset_t backing_pager_offset;
+
+               /* find the next compressed page at or after this offset */
+               backing_pager_offset = (backing_offset +
+                                       backing_object->paging_offset);
+               backing_pager_offset = vm_compressor_pager_next_compressed(
+                       backing_object->pager,
+                       backing_pager_offset);
+               if (backing_pager_offset == (memory_object_offset_t) -1) {
+                       /* no more compressed pages */
+                       break;
+               }
+               backing_offset = (backing_pager_offset -
+                                 backing_object->paging_offset);
+
+               new_offset = backing_offset - object->vo_shadow_offset;
+
+               if (new_offset >= object->vo_size) {
+                       /* we're out of the scope of "object": done */
+                       break;
+               }
+
+               if ((vm_page_lookup(object, new_offset) != VM_PAGE_NULL) ||
+                   (vm_compressor_pager_state_get(object->pager,
+                                                  (new_offset +
+                                                   object->paging_offset)) ==
+                    VM_EXTERNAL_STATE_EXISTS)) {
+                       /*
+                        * This page already exists in object, resident or
+                        * compressed.
+                        * We don't need this compressed page in backing_object
+                        * and it will be reclaimed when we release
+                        * backing_object.
+                        */
+                       continue;
+               }
 
-unsigned long vm_object_collapse_encrypted = 0;
+               /*
+                * 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));
+       }
+}
 
 /*
  *     Routine:        vm_object_do_collapse
@@ -3419,8 +4191,14 @@ vm_object_do_collapse(
        vm_object_offset_t new_offset, backing_offset;
        vm_object_size_t size;
 
-       backing_offset = object->shadow_offset;
-       size = object->size;
+       vm_object_lock_assert_exclusive(object);
+       vm_object_lock_assert_exclusive(backing_object);
+
+       assert(object->purgable == VM_PURGABLE_DENY);
+       assert(backing_object->purgable == VM_PURGABLE_DENY);
+
+       backing_offset = object->vo_shadow_offset;
+       size = object->vo_size;
 
        /*
         *      Move all in-memory pages from backing_object
@@ -3429,9 +4207,9 @@ vm_object_do_collapse(
         *      pages that shadow them.
         */
        
-       while (!queue_empty(&backing_object->memq)) {
+       while (!vm_page_queue_empty(&backing_object->memq)) {
                
-               p = (vm_page_t) queue_first(&backing_object->memq);
+               p = (vm_page_t) vm_page_queue_first(&backing_object->memq);
                
                new_offset = (p->offset - backing_offset);
                
@@ -3448,45 +4226,27 @@ vm_object_do_collapse(
                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) {
 
-                               /*
-                                *      Parent now has no page.
-                                *      Move the backing object's page up.
-                                */
-
-                               vm_page_rename(p, object, new_offset, TRUE);
-#if    MACH_PAGEMAP
-                       } else if (pp->absent) {
-
-                               /*
-                                *      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.
-                                */
-
-                               VM_PAGE_FREE(pp);
-                               vm_page_rename(p, object, new_offset, TRUE);
-#endif /* MACH_PAGEMAP */
+                               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);
+                               }
                        } else {
                                assert(! pp->absent);
 
@@ -3499,18 +4259,20 @@ vm_object_do_collapse(
                        }
                }
        }
-       
-#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 (backing_object->pager != MEMORY_OBJECT_NULL) {
-               vm_object_hash_entry_t  entry;
+       if (vm_object_collapse_compressor_allowed &&
+           object->pager != MEMORY_OBJECT_NULL &&
+           backing_object->pager != MEMORY_OBJECT_NULL) {
+
+               /* move compressed pages from backing_object to object */
+               vm_object_do_collapse_compressor(object, backing_object);
 
+       } else if (backing_object->pager != MEMORY_OBJECT_NULL) {
+
+               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.
                 *
@@ -3520,10 +4282,11 @@ vm_object_do_collapse(
                 */
 
                assert(!object->paging_in_progress);
+               assert(!object->activity_in_progress);
+               assert(!object->pager_created);
+               assert(object->pager == NULL);
                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;
@@ -3534,36 +4297,13 @@ vm_object_do_collapse(
                        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;
        }
-
-       vm_object_cache_unlock();
-
-#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 */
-
        /*
         *      Object now shadows whatever backing_object did.
         *      Note that the reference to backing_object->shadow
@@ -3574,10 +4314,13 @@ vm_object_do_collapse(
        assert(!backing_object->phys_contiguous);
        object->shadow = backing_object->shadow;
        if (object->shadow) {
-               object->shadow_offset += backing_object->shadow_offset;
+               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->shadow_offset = 0;
+               object->vo_shadow_offset = 0;
        }
        assert((object->shadow == VM_OBJECT_NULL) ||
               (object->shadow->copy != backing_object));
@@ -3589,22 +4332,43 @@ vm_object_do_collapse(
         *      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) &&
-              (backing_object->resident_page_count == 0) &&
-              (backing_object->paging_in_progress == 0));
+       assert(backing_object->ref_count == 1);
+       assert(backing_object->resident_page_count == 0);
+       assert(backing_object->paging_in_progress == 0);
+       assert(backing_object->activity_in_progress == 0);
+       assert(backing_object->shadow == VM_OBJECT_NULL);
+       assert(backing_object->vo_shadow_offset == 0);
+
+       if (backing_object->pager != MEMORY_OBJECT_NULL) {
+               /* ... unless it has a pager; need to terminate pager too */
+               vm_counters.do_collapse_terminate++;
+               if (vm_object_terminate(backing_object) != KERN_SUCCESS) {
+                       vm_counters.do_collapse_terminate_failure++;
+               }
+               return;
+       }
+
+       assert(backing_object->pager == NULL);
 
        backing_object->alive = FALSE;
        vm_object_unlock(backing_object);
 
        XPR(XPR_VM_OBJECT, "vm_object_collapse, collapsed 0x%X\n",
-               (integer_t)backing_object, 0,0,0,0);
+               backing_object, 0,0,0,0);
+
+#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_lock_destroy(backing_object);
 
        zfree(vm_object_zone, backing_object);
        
-       object_collapses++;
 }
 
 static void
@@ -3617,6 +4381,7 @@ vm_object_do_bypass(
         *      in the chain.
         */
        
+       vm_object_lock_assert_exclusive(object);
        vm_object_lock_assert_exclusive(backing_object);
 
 #if    TASK_SWAPPER
@@ -3643,10 +4408,10 @@ vm_object_do_bypass(
        assert(!backing_object->phys_contiguous);
        object->shadow = backing_object->shadow;
        if (object->shadow) {
-               object->shadow_offset += backing_object->shadow_offset;
+               object->vo_shadow_offset += backing_object->vo_shadow_offset;
        } else {
                /* no shadow, therefore no shadow offset... */
-               object->shadow_offset = 0;
+               object->vo_shadow_offset = 0;
        }
        
        /*
@@ -3663,7 +4428,7 @@ vm_object_do_bypass(
         *      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]
+        *      [with a caveat for "named" objects]
         * 
         *      The res_count on the backing object is
         *      conditionally decremented.  It's possible
@@ -3681,7 +4446,8 @@ vm_object_do_bypass(
         *      is temporary and cachable.
 #endif
         */
-       if (backing_object->ref_count > 1) {
+       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
@@ -3703,7 +4469,19 @@ vm_object_do_bypass(
                        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);
+
                vm_object_unlock(backing_object);
                vm_object_deallocate(backing_object);
 
@@ -3715,6 +4493,7 @@ vm_object_do_bypass(
                 */
 
                vm_object_lock(object);
+               vm_object_activity_end(object);
        }
        
        object_bypasses++;
@@ -3735,17 +4514,19 @@ 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,
+       vm_object_t                             object,
+       vm_object_offset_t                      hint_offset,
        boolean_t                               can_bypass)
 {
-       register vm_object_t                    backing_object;
-       register unsigned int                   rcount;
-       register unsigned int                   size;
+       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;
 
        vm_object_collapse_calls++;
 
@@ -3755,13 +4536,26 @@ vm_object_collapse(
        }
 
        XPR(XPR_VM_OBJECT, "vm_object_collapse, obj 0x%X\n", 
-               (integer_t)object, 0,0,0,0);
+               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++;
                /*
@@ -3780,23 +4574,27 @@ vm_object_collapse(
                        }
                        return;
                }
-       
+               if (backing_object_lock_type == OBJECT_LOCK_SHARED) {
+                       vm_object_lock_shared(backing_object);
+               } else {
+                       vm_object_lock(backing_object);
+               }
+
                /*
                 *      No pages in the object are currently
                 *      being paged out, and
                 */
-               if (object->paging_in_progress != 0) {
+               if (object->paging_in_progress != 0 ||
+                   object->activity_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;
+                       object_lock_type = backing_object_lock_type;
                        continue;
                }
 
-               vm_object_lock(backing_object);
-
                /*
                 *      ...
                 *              The backing object is not read_only,
@@ -3807,12 +4605,37 @@ vm_object_collapse(
                 */
        
                if (!backing_object->internal ||
-                   backing_object->paging_in_progress != 0) {
+                   backing_object->paging_in_progress != 0 ||
+                   backing_object->activity_in_progress != 0) {
+                       /* try and collapse the rest of the shadow chain */
+                       if (object != original_object) {
+                               vm_object_unlock(object);
+                       }
+                       object = backing_object;
+                       object_lock_type = backing_object_lock_type;
+                       continue;
+               }
+
+               /*
+                * Purgeable objects are not supposed to engage in
+                * copy-on-write activities, so should not have
+                * any shadow objects or be a shadow object to another
+                * object.
+                * Collapsing a purgeable object would require some
+                * updates to the purgeable compressed ledgers.
+                */
+               if (object->purgable != VM_PURGABLE_DENY ||
+                   backing_object->purgable != VM_PURGABLE_DENY) {
+                       panic("vm_object_collapse() attempting to collapse "
+                             "purgeable object: %p(%d) %p(%d)\n",
+                             object, object->purgable,
+                             backing_object, backing_object->purgable);
                        /* try and collapse the rest of the shadow chain */
                        if (object != original_object) {
                                vm_object_unlock(object);
                        }
                        object = backing_object;
+                       object_lock_type = backing_object_lock_type;
                        continue;
                }
        
@@ -3833,6 +4656,7 @@ vm_object_collapse(
                                vm_object_unlock(object);
                        }
                        object = backing_object;
+                       object_lock_type = backing_object_lock_type;
                        continue;
                }
 
@@ -3846,42 +4670,46 @@ vm_object_collapse(
                 *      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_compressor_allowed ||
+                    !object->pager_created 
+                    || (!backing_object->pager_created)
                    ) && vm_object_collapse_allowed) {
 
-                       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);
-
                        /*
-                        *      We need the cache lock for collapsing,
-                        *      but we must not deadlock.
+                        * We need the exclusive lock on the VM objects.
                         */
-                       
-                       if (! vm_object_cache_lock_try()) {
-                               if (object != original_object) {
-                                       vm_object_unlock(object);
-                               }
+                       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);
-                               return;
+                               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
@@ -3904,6 +4732,7 @@ vm_object_collapse(
                                vm_object_unlock(object);
                        }
                        object = backing_object;
+                       object_lock_type = backing_object_lock_type;
                        continue;
                }
 
@@ -3913,29 +4742,26 @@ vm_object_collapse(
                 *      we have to make sure no pages in the backing object
                 *      "show through" before bypassing it.
                 */
-               size = atop(object->size);
+               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;
-                       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 */
-                               ) {
+                       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;
                        }
 
@@ -3944,16 +4770,31 @@ vm_object_collapse(
                         *      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 */
-                               ) {
+                       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;
                        }
 
@@ -3970,18 +4811,10 @@ vm_object_collapse(
                         *
                         */
 
-                       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 */
+#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
@@ -3997,12 +4830,13 @@ vm_object_collapse(
                                             backing_offset, backing_rcount) &&
                            !EXISTS_IN_OBJECT(object, hint_offset, rcount)) {
                                /* dependency right at the hint */
-                               object->cow_hint = (vm_offset_t)hint_offset;
+                               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;
                        }
 
@@ -4012,44 +4846,32 @@ vm_object_collapse(
                         * 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 
+                        * 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 && 
-#if    MACH_PAGEMAP
-                           size > ((backing_object->existence_map) ?
-                            backing_rcount : (backing_rcount >> 1))
-#else
-                           size > (backing_rcount >> 1)
-#endif /* MACH_PAGEMAP */
-                               ) {
+                       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)queue_first(&backing_object->memq);
+                               p = (vm_page_t)vm_page_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);
-                                       }
-
                                        offset = (p->offset - backing_offset);
-                                       if (offset < object->size &&
+
+                                       if (offset < object->vo_size &&
                                            offset != hint_offset &&
                                            !EXISTS_IN_OBJECT(object, offset, rc)) {
                                                /* found a dependency */
-                                               object->cow_hint = (vm_offset_t)offset;
+                                               object->cow_hint = (vm_offset_t) offset; /* atomic */
+                                               
                                                break;
                                        }
-                                       p = (vm_page_t) queue_next(&p->listq);
+                                       p = (vm_page_t) vm_page_queue_next(&p->listq);
 
                                } while (--backing_rcount);
                                if (backing_rcount != 0 ) {
@@ -4058,6 +4880,7 @@ vm_object_collapse(
                                                vm_object_unlock(object);
                                        }
                                        object = backing_object;
+                                       object_lock_type = backing_object_lock_type;
                                        continue;
                                }
                        }
@@ -4066,29 +4889,18 @@ vm_object_collapse(
                         * 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 < object->vo_size) ?
                                      (offset + PAGE_SIZE_64) : 0) != hint_offset) {
 
-                                       /* Until we get more than one lookup lock */
-                                       if (lookups > 256) {
-                                               vm_object_collapse_delays++;
-                                               lookups = 0;
-                                               mutex_pause(0);
-                                       }
-
                                        if (EXISTS_IN_OBJECT(backing_object, offset +
                                            backing_offset, backing_rcount) &&
                                            !EXISTS_IN_OBJECT(object, offset, rcount)) {
                                                /* found a dependency */
-                                               object->cow_hint = (vm_offset_t)offset;
+                                               object->cow_hint = (vm_offset_t) offset; /* atomic */
                                                break;
                                        }
                                }
@@ -4098,11 +4910,24 @@ vm_object_collapse(
                                                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;
 
@@ -4122,9 +4947,12 @@ vm_object_collapse(
                continue;
        }
 
+       /* NOT REACHED */
+       /*
        if (object != original_object) {
                vm_object_unlock(object);
        }
+       */
 }
 
 /*
@@ -4143,11 +4971,11 @@ 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)
+       vm_object_t             object,
+       vm_object_offset_t      start,
+       vm_object_offset_t      end)
 {
-       register vm_page_t      p, next;
+       vm_page_t       p, next;
 
        /*
         *      One and two page removals are most popular.
@@ -4161,22 +4989,22 @@ vm_object_page_remove(
                for (; start < end; start += PAGE_SIZE_64) {
                        p = vm_page_lookup(object, start);
                        if (p != VM_PAGE_NULL) {
-                               assert(!p->cleaning && !p->pageout);
+                               assert(!p->cleaning && !p->laundry);
                                if (!p->fictitious && p->pmapped)
-                                       pmap_disconnect(p->phys_page);
+                                       pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
                                VM_PAGE_FREE(p);
                        }
                }
        } else {
                vm_object_page_remove_iterate++;
 
-               p = (vm_page_t) queue_first(&object->memq);
-               while (!queue_end(&object->memq, (queue_entry_t) p)) {
-                       next = (vm_page_t) queue_next(&p->listq);
+               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->pageout);
+                               assert(!p->cleaning && !p->laundry);
                                if (!p->fictitious && p->pmapped)
-                                       pmap_disconnect(p->phys_page);
+                                       pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(p));
                                VM_PAGE_FREE(p);
                        }
                        p = next;
@@ -4212,7 +5040,7 @@ static int vm_object_coalesce_count = 0;
 
 __private_extern__ boolean_t
 vm_object_coalesce(
-       register vm_object_t            prev_object,
+       vm_object_t                     prev_object,
        vm_object_t                     next_object,
        vm_object_offset_t              prev_offset,
        __unused vm_object_offset_t next_offset,
@@ -4235,7 +5063,7 @@ vm_object_coalesce(
 
        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);
+               prev_object, prev_offset, prev_size, next_size, 0);
 
        vm_object_lock(prev_object);
 
@@ -4261,7 +5089,8 @@ vm_object_coalesce(
            (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->paging_in_progress != 0) ||
+           (prev_object->activity_in_progress != 0)) {
                vm_object_unlock(prev_object);
                return(FALSE);
        }
@@ -4280,401 +5109,14 @@ vm_object_coalesce(
         *      Extend the object if necessary.
         */
        newsize = prev_offset + prev_size + next_size;
-       if (newsize > prev_object->size) {
-#if    MACH_PAGEMAP
-               /*
-                *      We cannot extend an object that has existence info,
-                *      since the existence info might then fail to cover
-                *      the entire object.
-                *
-                *      This assertion must be true because the object
-                *      has no pager, and we only create existence info
-                *      for objects with pagers.
-                */
-               assert(prev_object->existence_map == VM_EXTERNAL_NULL);
-#endif /* MACH_PAGEMAP */
-               prev_object->size = newsize;
+       if (newsize > prev_object->vo_size) {
+               prev_object->vo_size = newsize;
        }
 
        vm_object_unlock(prev_object);
        return(TRUE);
 }
 
-/*
- *     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;
-
-       num_pages = atop_64(size);
-
-       for (i = 0; i < num_pages; i++, offset += PAGE_SIZE_64) {
-
-           addr = (*map_fn)(map_fn_data, offset);
-
-           while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL)
-               vm_page_more_fictitious();
-
-           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();
-           }
-
-           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);
-
-           PAGE_WAKEUP_DONE(m);
-           vm_object_unlock(object);
-       }
-}
-
-#include <mach_kdb.h>
-
-#if    MACH_KDB
-#include <ddb/db_output.h>
-#include <vm/vm_print.h>
-
-#define printf kdbprintf
-
-extern boolean_t       vm_object_cached(
-                               vm_object_t object);
-
-extern void            print_bitstring(
-                               char byte);
-
-boolean_t      vm_object_print_pages = FALSE;
-
-void
-print_bitstring(
-       char byte)
-{
-       printf("%c%c%c%c%c%c%c%c",
-              ((byte & (1 << 0)) ? '1' : '0'),
-              ((byte & (1 << 1)) ? '1' : '0'),
-              ((byte & (1 << 2)) ? '1' : '0'),
-              ((byte & (1 << 3)) ? '1' : '0'),
-              ((byte & (1 << 4)) ? '1' : '0'),
-              ((byte & (1 << 5)) ? '1' : '0'),
-              ((byte & (1 << 6)) ? '1' : '0'),
-              ((byte & (1 << 7)) ? '1' : '0'));
-}
-
-boolean_t
-vm_object_cached(
-       register vm_object_t object)
-{
-       register vm_object_t o;
-
-       queue_iterate(&vm_object_cached_list, o, vm_object_t, cached_list) {
-               if (object == o) {
-                       return TRUE;
-               }
-       }
-       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");
-       }
-       return;
-}
-#endif /* MACH_PAGEMAP */
-
-int
-vm_follow_object(
-       vm_object_t object)
-{
-       int count = 0;
-       int orig_db_indent = db_indent;
-
-       while (TRUE) {
-               if (object == VM_OBJECT_NULL) {
-                       db_indent = orig_db_indent;
-                       return count;
-               }
-
-               count += 1;
-
-               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);
-
-               db_indent += 2;
-               object = object->shadow;
-       }
-
-}
-
-/*
- *     vm_object_print:        [ debug ]
- */
-void
-vm_object_print(db_expr_t db_addr, __unused boolean_t have_addr,
-               __unused db_expr_t arg_count, __unused char *modif)
-{
-       vm_object_t     object;
-       register vm_page_t p;
-       const char *s;
-
-       register int count;
-
-       object = (vm_object_t) (long) db_addr;
-       if (object == VM_OBJECT_NULL)
-               return;
-
-       iprintf("object 0x%x\n", object);
-
-       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);
-
-       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;
-
-               case MEMORY_OBJECT_COPY_CALL:
-               printf("copy_call");
-               break;
-
-               case MEMORY_OBJECT_COPY_DELAY:
-               printf("copy_delay");
-               break;
-
-               case MEMORY_OBJECT_COPY_SYMMETRIC:
-               printf("copy_symmetric");
-               break;
-
-               case MEMORY_OBJECT_COPY_INVALID:
-               printf("copy_invalid");
-               break;
-
-               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 */
-
-       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++;
-
-                       printf("(off=0x%llX,page=%p)", p->offset, p);
-                       p = (vm_page_t) queue_next(&p->listq);
-               }
-               if (count != 0) {
-                       printf("\n");
-               }
-       }
-       db_indent -= 2;
-}
-
-
-/*
- *     vm_object_find          [ debug ]
- *
- *     Find all tasks which reference the given vm_object.
- */
-
-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 (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;
-                       }
-               }
-       }
-
-       return(found);
-}
-
-#endif /* MACH_KDB */
-
 kern_return_t
 vm_object_populate_with_private(
                vm_object_t             object,
@@ -4686,71 +5128,67 @@ vm_object_populate_with_private(
        vm_object_offset_t      base_offset;
 
 
-       if(!object->private)
+       if (!object->private)
                return KERN_FAILURE;
 
        base_page = phys_page;
 
        vm_object_lock(object);
-       if(!object->phys_contiguous) {
+
+       if (!object->phys_contiguous) {
                vm_page_t       m;
-               if((base_offset = trunc_page_64(offset)) != offset) {
+
+               if ((base_offset = trunc_page_64(offset)) != offset) {
                        vm_object_unlock(object);
                        return KERN_FAILURE;
                }
                base_offset += object->paging_offset;
-               while(size) {
+
+               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) {
+
+                       if (m != VM_PAGE_NULL) {
+                               if (m->fictitious) {
+                                       if (VM_PAGE_GET_PHYS_PAGE(m) != 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();
+
+                                               m->fictitious = FALSE;
+                                               VM_PAGE_SET_PHYS_PAGE(m, base_page);
                                        }
-                               } else if (m->phys_page != base_page) {
-                                       if (m->pmapped) {
+                               } 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(m->phys_page);
+                                               pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m));
                                        }
-                                       m->phys_page = base_page;
+                                       VM_PAGE_SET_PHYS_PAGE(m, base_page);
                                }
 
-                               /*
-                                * ENCRYPTED SWAP:
-                                * We're not pointing to the same
-                                * physical page any longer and the
-                                * contents of the new one are not
-                                * supposed to be encrypted.
-                                * XXX What happens to the original
-                                * physical page. Is it lost ?
-                                */
-                               m->encrypted = FALSE;
-
                        } else {
-                               while ((m = vm_page_grab_fictitious()) 
-                                                        == VM_PAGE_NULL)
+                               while ((m = vm_page_grab_fictitious()) == VM_PAGE_NULL)
                                        vm_page_more_fictitious();      
-                               vm_page_lockspin_queues();
-                               m->fictitious = FALSE;
+
+                               /*
+                                * private normally requires lock_queues but since we
+                                * are initializing the page, its not necessary here
+                                */
                                m->private = TRUE;
-                               m->phys_page = base_page;
-                               m->list_req_pending = TRUE;
-                               m->absent = TRUE;
+                               m->fictitious = FALSE;
+                               VM_PAGE_SET_PHYS_PAGE(m, base_page);
                                m->unusual = TRUE;
-                               vm_page_unlock_queues();
+                               m->busy = FALSE;
+
                                vm_page_insert(m, object, base_offset);
                        }
                        base_page++;                                                                    /* Go to the next physical page */
@@ -4766,93 +5204,15 @@ vm_object_populate_with_private(
                
                /* 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;
+               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,
-       memory_object_pager_ops_t pager_ops,
-       int             *count)
-{
-
-       int     object_released = 0;
-
-       register 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--;
 
-                       /*
-                       *       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;
        return KERN_SUCCESS;
 }
 
 
-
 kern_return_t
 memory_object_create_named(
        memory_object_t pager,
@@ -4860,23 +5220,17 @@ memory_object_create_named(
        memory_object_control_t         *control)
 {
        vm_object_t             object;
-       vm_object_hash_entry_t  entry;
 
        *control = MEMORY_OBJECT_CONTROL_NULL;
        if (pager == MEMORY_OBJECT_NULL)
                return KERN_INVALID_ARGUMENT;
 
-       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_cache_unlock();
-       if ((object = vm_object_enter(pager, size, FALSE, FALSE, TRUE))
-           == VM_OBJECT_NULL) {
-               return(KERN_INVALID_OBJECT);
+       object = vm_object_memory_object_associate(pager,
+                                                  VM_OBJECT_NULL,
+                                                  size,
+                                                  TRUE);
+       if (object == VM_OBJECT_NULL) {
+               return KERN_INVALID_OBJECT;
        }
        
        /* wait for object (if any) to be ready */
@@ -4914,50 +5268,29 @@ memory_object_recover_named(
 {
        vm_object_t             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);
        }
-
 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;
        }
 
        if (!object->alive) {
-               vm_object_cache_unlock();
                vm_object_unlock(object);
                return KERN_FAILURE;
        }
 
        if (object->named == TRUE) {
-               vm_object_cache_unlock();
                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_cache_unlock();
-
        object->named = TRUE;
        vm_object_lock_assert_exclusive(object);
        object->ref_count++;
@@ -4999,17 +5332,10 @@ vm_object_release_name(
 
        while (object != VM_OBJECT_NULL) {
 
-               /*
-                *      The cache holds a reference (uncounted) to
-                *      the object.  We must locke it before removing
-                *      the object.
-                *
-                */
-               
-               vm_object_cache_lock();
                vm_object_lock(object);
+
                assert(object->alive);
-               if(original_object)
+               if (original_object)
                        assert(object->named);
                assert(object->ref_count > 0);
 
@@ -5024,7 +5350,6 @@ vm_object_release_name(
                                        VM_OBJECT_EVENT_INITIALIZED,
                                        THREAD_UNINT);
                        vm_object_unlock(object);
-                       vm_object_cache_unlock();
                        thread_block(THREAD_CONTINUE_NULL);
                        continue;
                }
@@ -5033,22 +5358,19 @@ vm_object_release_name(
                        && (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) {
                                vm_object_unlock(object);
-                               vm_object_cache_unlock();
                                return KERN_SUCCESS;
                        }
                }
                
                if ((flags & MEMORY_OBJECT_RESPECT_CACHE) &&
                                        (object->ref_count == 1)) {
-                       if(original_object)
+                       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);
@@ -5056,9 +5378,10 @@ vm_object_release_name(
                }
                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) {
+
+               if (object->ref_count == 1) {
+                       if (vm_object_terminate(object) != KERN_SUCCESS) {
+                               if (original_object) {
                                        return KERN_FAILURE;
                                } else {
                                        return KERN_SUCCESS;
@@ -5077,7 +5400,6 @@ vm_object_release_name(
                        if(original_object)
                                object->named = FALSE;
                        vm_object_unlock(object);
-                       vm_object_cache_unlock();
                        return KERN_SUCCESS;
                }
        }
@@ -5102,7 +5424,7 @@ vm_object_lock_request(
 
         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, 
+           object, offset, size, 
            (((should_return&1)<<1)|should_flush), prot);
 
        /*
@@ -5141,125 +5463,127 @@ vm_object_lock_request(
  * 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.
+ * On entry the object must be locked and it must be
+ * purgeable with no delayed copies pending.
  */
-unsigned int
-vm_object_purge(vm_object_t object)
+void
+vm_object_purge(vm_object_t object, int flags)
 {
-       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;
+       unsigned int    object_page_count = 0;
+       unsigned int    pgcount = 0;
+       boolean_t       skipped_object = FALSE;
+
+        vm_object_lock_assert_exclusive(object);
 
-       assert(object->purgable != VM_PURGABLE_NONVOLATILE);
-       object->purgable = VM_PURGABLE_EMPTY;
+       if (object->purgable == VM_PURGABLE_DENY)
+               return;
 
        assert(object->copy == VM_OBJECT_NULL);
        assert(object->copy_strategy == MEMORY_OBJECT_COPY_NONE);
-       purge_loop_quota = PURGE_LOOP_QUOTA;
-
-       local_freeq = VM_PAGE_NULL;
-       local_freed = 0;
 
        /*
-        * Go through the object's resident pages and try and discard them.
+        * 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()).
         */
-       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 (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) {
-                               /*
-                                * Flush our queue of pages to free.
-                                */
-                               vm_page_free_list(local_freeq);
-                               local_freeq = VM_PAGE_NULL;
-                               local_freed = 0;
-                       }
-                       mutex_yield(&vm_page_queue_lock);
-
-                       /* 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 (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 (p->wire_count) {
-                       /* don't discard a wired page */
-                       continue;
+               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;
 
-               assert(!p->laundry);
-               assert(p->object != kernel_object);
-
-               /* we can discard this page */
+       vm_object_reap_pages(object, REAP_PURGEABLE);
 
-               /* advertize that this page is in a transition state */
-               p->busy = TRUE;
+       if (object->pager != NULL) {
 
-               if (p->pmapped == TRUE) {
-                       /* unmap the page */
-                       int refmod_state;
+               assert(VM_CONFIG_COMPRESSOR_IS_PRESENT);
 
-                       refmod_state = pmap_disconnect(p->phys_page);
-                       if (refmod_state & VM_MEM_MODIFIED) {
-                               p->dirty = TRUE;
+               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 (p->dirty || p->precious) {
-                       /* we saved the cost of cleaning this page ! */
-                       num_purged_pages++;
-                       vm_page_purged_count++;
-               }
-
-               vm_page_free_prepare(p);
-
-               /* ... 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;
+                       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;
                }
        }
 
-       /* 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;
-       }
+       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);
 
-       return num_purged_pages;
 }
+                               
 
 /*
  * vm_object_purgeable_control() allows the caller to control and investigate the
@@ -5352,6 +5676,8 @@ vm_object_purgable_control(
                return KERN_INVALID_ARGUMENT;
        }
 
+       vm_object_lock_assert_exclusive(object);
+
        /*
         * Get current state of the purgeable object.
         */
@@ -5371,39 +5697,125 @@ vm_object_purgable_control(
                return KERN_SUCCESS;
        }
 
-       new_state = *state & VM_PURGABLE_STATE_MASK;
-       switch (new_state) {
-       case VM_PURGABLE_DENY:
-       case VM_PURGABLE_NONVOLATILE:
-               object->purgable = new_state;
+       if (control == VM_PURGABLE_SET_STATE &&
+           object->purgeable_only_by_kernel) {
+               return KERN_PROTECTION_FAILURE;
+       }
 
-               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 (control != VM_PURGABLE_SET_STATE &&
+           control != VM_PURGABLE_SET_STATE_FROM_KERNEL) {
+               return KERN_INVALID_ARGUMENT;
+       }
 
-                       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);
+       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) {
+               if (old_state == VM_PURGABLE_EMPTY) {
+                       /* what's been emptied must stay empty */
+                       new_state = VM_PURGABLE_EMPTY;
+               }
+               if (object->volatile_empty) {
+                       /* debugging mode: go straight to empty */
+                       new_state = VM_PURGABLE_EMPTY;
+               }
+       }
+
+       switch (new_state) {
+       case VM_PURGABLE_DENY:
+               /*
+                * Attempting to convert purgeable memory to non-purgeable:
+                * not allowed.
+                */
+               return KERN_INVALID_ARGUMENT;
+       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_purgeable_token_delete_first(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);
+                               }
+                       }
+               }
+
+               assert(old_state != VM_PURGABLE_EMPTY);
 
-               if ((old_state != VM_PURGABLE_NONVOLATILE) && (old_state != VM_PURGABLE_VOLATILE))
-                       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];
+                       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];
@@ -5411,25 +5823,55 @@ vm_object_purgable_control(
                                queue = &purgeable_queues[PURGEABLE_Q_TYPE_LIFO];
                }
         
-               if (old_state == VM_PURGABLE_NONVOLATILE) {
-                       /* try to add token... this can fail */
-                       vm_page_lock_queues();
+               if (old_state == VM_PURGABLE_NONVOLATILE ||
+                   old_state == VM_PURGABLE_EMPTY) {
+                       unsigned int delta;
 
-                       kern_return_t result = vm_purgeable_token_add(queue);
-                       if (result != KERN_SUCCESS) {
-                               vm_page_unlock_queues();
-                               return result;
+                       if ((*state & VM_PURGABLE_NO_AGING_MASK) ==
+                           VM_PURGABLE_NO_AGING) {
+                               object->purgeable_when_ripe = FALSE;
+                       } else {
+                               object->purgeable_when_ripe = TRUE;
                        }
-                       vm_page_purgeable_count += object->resident_page_count;
+                               
+                       if (object->purgeable_when_ripe) {
+                               kern_return_t result;
 
-                       vm_page_unlock_queues();
+                               /* 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 not be on a queue */
-                       assert(object->objq.next == NULL && object->objq.prev == NULL);
+                       /* 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.
@@ -5440,22 +5882,40 @@ vm_object_purgable_control(
                         */
                        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);
+                       old_queue = vm_purgeable_object_remove(object);
                        assert(old_queue);
             
-                       if (old_queue != 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();
-                               vm_purgeable_token_delete_first(old_queue);
-                               result = vm_purgeable_token_add(queue);
+                               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();
 
-                               assert(result==KERN_SUCCESS);   /* this should never fail since we just freed a token */
                        }
                };
                vm_purgeable_object_add(object, queue, (*state&VM_VOLATILE_GROUP_MASK)>>VM_VOLATILE_GROUP_SHIFT );
+               if (old_state == VM_PURGABLE_NONVOLATILE) {
+                       vm_purgeable_accounting(object, VM_PURGABLE_NONVOLATILE,
+                                               FALSE);
+               }
 
                assert(queue->debug_count_objects>=0);
         
@@ -5463,32 +5923,167 @@ vm_object_purgable_control(
 
 
        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 (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_NONVOLATILE) {
-                               vm_page_purgeable_count += object->resident_page_count;
+               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();
                        }
-                       (void) vm_object_purge(object);
-                       vm_page_unlock_queues();
                }
-               break;
 
+               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
@@ -5581,7 +6176,7 @@ vm_object_res_reference(
 #endif
 __private_extern__ void
 vm_object_reference(
-       register vm_object_t    object)
+       vm_object_t     object)
 {
        if (object == VM_OBJECT_NULL)
                return;
@@ -5592,29 +6187,6 @@ vm_object_reference(
        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
  *
@@ -5625,6 +6197,7 @@ adjust_vm_object_cache(
  *
  * 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,
@@ -5634,13 +6207,11 @@ vm_object_transpose(
        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;
 
        tmp_object = VM_OBJECT_NULL;
        object1_locked = FALSE; object2_locked = FALSE;
-       object1_paging = FALSE; object2_paging = FALSE;
 
        if (object1 == object2 ||
            object1 == VM_OBJECT_NULL ||
@@ -5653,6 +6224,29 @@ vm_object_transpose(
                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 ||
@@ -5665,17 +6259,19 @@ vm_object_transpose(
                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
+        * 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_begin(object1);
-       object1_paging = TRUE;
-       vm_object_unlock(object1);
-       object1_locked = FALSE;
+       vm_object_paging_only_wait(object1, THREAD_UNINT);
 
        /*
         * Same as above for the 2nd object...
@@ -5688,37 +6284,11 @@ vm_object_transpose(
                retval = KERN_INVALID_VALUE;
                goto done;
        }
-       vm_object_paging_begin(object2);
-       object2_paging = TRUE;
-       vm_object_unlock(object2);
-       object2_locked = FALSE;
-
-       /*
-        * 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;
+       vm_object_paging_only_wait(object2, THREAD_UNINT);
 
-       /*
-        * 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);
-       }
-       object1_locked = TRUE;
-       object2_locked = TRUE;
 
-       if (object1->size != object2->size ||
-           object1->size != transpose_size) {
+       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.
@@ -5736,54 +6306,52 @@ vm_object_transpose(
         * 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)) {
+       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 (!queue_empty(&object2->memq)) {
-                       page = (vm_page_t) queue_first(&object2->memq);
-                       vm_page_rename(page, object1, page->offset, FALSE);
+               while (!vm_page_queue_empty(&object2->memq)) {
+                       page = (vm_page_t) vm_page_queue_first(&object2->memq);
+                       vm_page_rename(page, object1, page->offset);
                }
-               assert(queue_empty(&object2->memq));
-       } else if (object2->phys_contiguous || queue_empty(&object2->memq)) {
+               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 (!queue_empty(&object1->memq)) {
-                       page = (vm_page_t) queue_first(&object1->memq);
-                       vm_page_rename(page, object2, page->offset, FALSE);
+               while (!vm_page_queue_empty(&object1->memq)) {
+                       page = (vm_page_t) vm_page_queue_first(&object1->memq);
+                       vm_page_rename(page, object2, page->offset);
                }
-               assert(queue_empty(&object1->memq));
+               assert(vm_page_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);
+               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);
+                       vm_page_remove(page, TRUE);
                        page->offset = page_offset;
-                       queue_enter(&tmp_object->memq, page, vm_page_t, listq);
+                       vm_page_queue_enter(&tmp_object->memq, page, vm_page_t, listq);
                }
-               vm_page_unlock_queues();
-               assert(queue_empty(&object1->memq));
+               assert(vm_page_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);
+               while (!vm_page_queue_empty(&object2->memq)) {
+                       page = (vm_page_t) vm_page_queue_first(&object2->memq);
+                       vm_page_rename(page, object1, page->offset);
+               }
+               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(queue_empty(&tmp_object->memq));
+               assert(vm_page_queue_empty(&tmp_object->memq));
        }
 
 #define __TRANSPOSE_FIELD(field)                               \
@@ -5793,21 +6361,26 @@ MACRO_BEGIN                                                     \
        object2->field = tmp_object->field;                     \
 MACRO_END
 
-       /* "size" should be identical */
-       assert(object1->size == object2->size);
        /* "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 */
+       assert(object1->ref_count >= 1);
+       assert(object2->ref_count >= 1);
 #if TASK_SWAPPER
        /* "res_count" refers to the object not its contents */
 #endif
        /* "resident_page_count" was updated above when transposing pages */
+       /* "wired_page_count" was updated above when transposing pages */
+       /* "reusable_page_count" was updated above when transposing pages */
        /* there should be no "copy" */
        assert(!object1->copy);
        assert(!object2->copy);
        /* there should be no "shadow" */
        assert(!object1->shadow);
        assert(!object2->shadow);
-       __TRANSPOSE_FIELD(shadow_offset); /* used by phys_contiguous objects */
+       __TRANSPOSE_FIELD(vo_shadow_offset); /* used by phys_contiguous objects */
        __TRANSPOSE_FIELD(pager);
        __TRANSPOSE_FIELD(paging_offset);
        __TRANSPOSE_FIELD(pager_control);
@@ -5822,8 +6395,10 @@ MACRO_END
        }
        __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->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);
@@ -5831,7 +6406,6 @@ MACRO_END
        __TRANSPOSE_FIELD(pager_trusted);
        __TRANSPOSE_FIELD(can_persist);
        __TRANSPOSE_FIELD(internal);
-       __TRANSPOSE_FIELD(temporary);
        __TRANSPOSE_FIELD(private);
        __TRANSPOSE_FIELD(pageout);
        /* "alive" should be set */
@@ -5841,41 +6415,59 @@ MACRO_END
        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(purgeable_when_ripe);
        __TRANSPOSE_FIELD(true_share);
        /* "terminating" should not be set */
        assert(!object1->terminating);
        assert(!object2->terminating);
+       /* transfer "named" reference if needed */
+       if (object1->named && !object2->named) {
+               assert(object1->ref_count >= 2);
+               assert(object2->ref_count >= 1);
+               object1->ref_count--;
+               object2->ref_count++;
+       } else if (!object1->named && object2->named) {
+               assert(object1->ref_count >= 1);
+               assert(object2->ref_count >= 2);
+               object1->ref_count++;
+               object2->ref_count--;
+       }
        __TRANSPOSE_FIELD(named);
        /* "shadow_severed" refers to the object not its contents */
        __TRANSPOSE_FIELD(phys_contiguous);
        __TRANSPOSE_FIELD(nophyscache);
-       /* "cached_list" should be NULL */
+       /* "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(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(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);
-       __TRANSPOSE_FIELD(not_in_use);
-#ifdef UPL_DEBUG
+       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
 
@@ -5886,7 +6478,6 @@ done:
         * Cleanup.
         */
        if (tmp_object != VM_OBJECT_NULL) {
-               vm_object_paging_end(tmp_object);
                vm_object_unlock(tmp_object);
                /*
                 * Re-initialize the temporary object to avoid
@@ -5905,25 +6496,15 @@ done:
                vm_object_unlock(object2);
                object2_locked = FALSE;
        }
-       if (object1_paging) {
-               vm_object_lock(object1);
-               vm_object_paging_end(object1);
-               vm_object_unlock(object1);
-               object1_paging = FALSE;
-       }
-       if (object2_paging) {
-               vm_object_lock(object2);
-               vm_object_paging_end(object2);
-               vm_object_unlock(object2);
-               object2_paging = FALSE;
-       }
+
+       vm_object_transpose_count++;
 
        return retval;
 }
 
 
 /*
- *      vm_object_build_cluster
+ *      vm_object_cluster_size
  *
  *      Determine how big a cluster we should issue an I/O for...
  *
@@ -5937,14 +6518,24 @@ done:
  */
 extern int speculative_reads_disabled;
 
-uint32_t pre_heat_scaling[MAX_UPL_TRANSFER];
-uint32_t pre_heat_cluster[MAX_UPL_TRANSFER];
+/*
+ * 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.
+ */
+#if CONFIG_EMBEDDED
+       unsigned int preheat_max_bytes = (1024 * 512);
+#else /* CONFIG_EMBEDDED */
+       unsigned int preheat_max_bytes = MAX_UPL_TRANSFER_BYTES;
+#endif /* CONFIG_EMBEDDED */
+unsigned int preheat_min_bytes = (1024 * 32);
 
-#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)
+                      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;
@@ -5958,22 +6549,29 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
        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;
 
        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);
+       /*
+        * 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 || max_length == 0) {
+       if (speculative_reads_disabled || fault_info == NULL) {
                /*
                 * no cluster... just fault the page in
                 */
@@ -5981,17 +6579,52 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
        }
        orig_start = *start;
        target_start = orig_start;
-       cluster_size = round_page_32(fault_info->cluster_size);
+       cluster_size = round_page(fault_info->cluster_size);
        behavior = fault_info->behavior;
 
        vm_object_lock(object);
 
+       if (object->pager == MEMORY_OBJECT_NULL)
+               goto out;       /* pager is gone for this object, nothing more to do */
+
+       vnode_pager_get_isSSD(object->pager, &isSSD);
+
+       min_ph_size = round_page(preheat_min_bytes);
+       max_ph_size = round_page(preheat_max_bytes);
+
+#if !CONFIG_EMBEDDED
+       if (isSSD) {
+               min_ph_size /= 2;
+               max_ph_size /= 8;
+
+               if (min_ph_size & PAGE_MASK_64) {
+                       min_ph_size = trunc_page(min_ph_size);
+               }
+
+               if (max_ph_size & PAGE_MASK_64) {
+                       max_ph_size = trunc_page(max_ph_size);
+               }
+       }
+#endif /* !CONFIG_EMBEDDED */
+
+       if (min_ph_size < PAGE_SIZE)
+               min_ph_size = PAGE_SIZE;
+
+       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;
+
+       if (max_length > max_ph_size) 
+               max_length = max_ph_size;
+
+       if (max_length <= PAGE_SIZE)
+               goto out;
+
        if (object->internal)
-               object_size = object->size;
-       else if (object->pager != MEMORY_OBJECT_NULL)
-               vnode_pager_get_object_size(object->pager, &object_size);
+               object_size = object->vo_size;
        else
-               goto out;       /* pager is gone for this object, nothing more to do */
+               vnode_pager_get_object_size(object->pager, &object_size);
 
        object_size = round_page_64(object_size);
 
@@ -6017,8 +6650,9 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                  } else {
                          sequential_behavior = VM_BEHAVIOR_SEQUENTIAL;
                  }
+
        }
-       switch(behavior) {
+       switch (behavior) {
 
        default:
                behavior = VM_BEHAVIOR_DEFAULT;
@@ -6027,33 +6661,35 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                if (object->internal && fault_info->user_tag == VM_MEMORY_STACK)
                        goto out;
 
-               if (sequential_run >= (3 * PAGE_SIZE)) {
+               if (sequential_run >= (3 * PAGE_SIZE)) {
                        pre_heat_size = sequential_run + PAGE_SIZE;
 
-                       if ((behavior = sequential_behavior) == VM_BEHAVIOR_SEQUENTIAL)
+                       if (sequential_behavior == VM_BEHAVIOR_SEQUENTIAL)
                                look_behind = FALSE;
                        else
                                look_ahead = FALSE;
+
+                       *io_streaming = 1;
                } else {
-                       uint32_t        pages_unused;
 
-                       if (object->pages_created < 32 * PRE_HEAT_MULTIPLIER) {
+                       if (object->pages_created < (20 * (min_ph_size >> PAGE_SHIFT))) {
                                /*
                                 * 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;
+                               pre_heat_size = min_ph_size;
                        } else {
-                               pre_heat_size = PAGE_SIZE * 4 * PRE_HEAT_MULTIPLIER;
+                               /*
+                                * Linear growth in PH size: The maximum size is max_length...
+                                * this cacluation will result in a size that is neither a 
+                                * power of 2 nor a multiple of PAGE_SIZE... so round
+                                * it up to the nearest PAGE_SIZE boundary
+                                */
+                               pre_heat_size = (max_length * (uint64_t)object->pages_used) / object->pages_created;
+
+                               if (pre_heat_size < min_ph_size)
+                                       pre_heat_size = min_ph_size;
+                               else
+                                       pre_heat_size = round_page(pre_heat_size);
                        }
                }
                break;
@@ -6067,6 +6703,7 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                if ((pre_heat_size = cluster_size) == 0)
                        pre_heat_size = sequential_run + PAGE_SIZE;
                look_behind = FALSE;
+               *io_streaming = 1;
 
                break;
 
@@ -6074,30 +6711,81 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                if ((pre_heat_size = cluster_size) == 0)
                        pre_heat_size = sequential_run + PAGE_SIZE;
                look_ahead = FALSE;
+               *io_streaming = 1;
 
                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 && vm_page_free_count < vm_page_free_target)
-               pre_heat_size /= 2;
+       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)
-                       target_start &= ~(pre_heat_size - 1);
+               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 ((target_start + pre_heat_size) > object_size)
-                       pre_heat_size = (vm_size_t)(trunc_page_64(object_size - target_start));
+                       if (target_start > head_size)
+                               target_start -= head_size;
+                       else
+                               target_start = 0;
 
-               tail_size = pre_heat_size - (orig_start - target_start) - PAGE_SIZE;
+                       /*
+                        * '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)
-                       pre_heat_size = target_start;
+               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;
        }
-       pre_heat_scaling[pre_heat_size / PAGE_SIZE]++;
+       assert( !(target_start & PAGE_MASK_64));
+       assert( !(pre_heat_size & PAGE_MASK_64));
 
        if (pre_heat_size <= PAGE_SIZE)
                goto out;
@@ -6105,7 +6793,9 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
        if (look_behind == TRUE) {
                /*
                 * take a look at the pages before the original
-                * faulting offset 
+                * 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;
 
@@ -6115,19 +6805,13 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                         */
                        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
+                       /*
+                        * for external objects or internal objects w/o a pager,
+                        * VM_COMPRESSOR_PAGER_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;
+                       if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset) == VM_EXTERNAL_STATE_ABSENT) {
+                               break;
                        }
-#endif
                        if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
                                /*
                                 * don't bridge resident pages
@@ -6145,19 +6829,15 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                         */
                        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
+                       assert(offset < object_size);
+
+                       /*
+                        * for external objects or internal objects w/o a pager,
+                        * VM_COMPRESSOR_PAGER_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;
+                       if (VM_COMPRESSOR_PAGER_STATE_GET(object, offset) == VM_EXTERNAL_STATE_ABSENT) {
+                               break;
                        }
-#endif
                        if (vm_page_lookup(object, offset) != VM_PAGE_NULL) {
                                /*
                                 * don't bridge resident pages
@@ -6168,9 +6848,12 @@ vm_object_cluster_size(vm_object_t object, vm_object_offset_t *start,
                }
        }
 out:
-       pre_heat_cluster[*length / PAGE_SIZE]++;
+       if (*length > max_length)
+               *length = max_length;
 
        vm_object_unlock(object);
+       
+       DTRACE_VM1(clustersize, vm_size_t, *length);
 }
 
 
@@ -6195,7 +6878,7 @@ vm_object_page_op(
                if(object->phys_contiguous) {
                        if (phys_entry) {
                                *phys_entry = (ppnum_t)
-                                       (object->shadow_offset >> PAGE_SHIFT);
+                                       (object->vo_shadow_offset >> PAGE_SHIFT);
                        }
                        vm_object_unlock(object);
                        return KERN_SUCCESS;
@@ -6227,12 +6910,9 @@ vm_object_page_op(
 
                if (ops & UPL_POP_DUMP) {
                        if (dst_page->pmapped == TRUE)
-                               pmap_disconnect(dst_page->phys_page);
-
-                       vm_page_lock_queues();
-                       vm_page_free(dst_page);
-                       vm_page_unlock_queues();
+                               pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page));
 
+                       VM_PAGE_FREE(dst_page);
                        break;
                }
 
@@ -6243,7 +6923,7 @@ vm_object_page_op(
                        /* are undertaken */
 
                        if(dst_page->dirty) *flags |= UPL_POP_DIRTY;
-                       if(dst_page->pageout) *flags |= UPL_POP_PAGEOUT;
+                       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;
@@ -6260,8 +6940,10 @@ vm_object_page_op(
                        /* 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_DIRTY) {
+                               SET_PAGE_DIRTY(dst_page, FALSE);
+                       }
+                       if (ops & UPL_POP_PAGEOUT) dst_page->free_when_done = TRUE;
                        if (ops & UPL_POP_PRECIOUS) dst_page->precious = TRUE;
                        if (ops & UPL_POP_ABSENT) dst_page->absent = TRUE;
                        if (ops & UPL_POP_BUSY) dst_page->busy = TRUE;
@@ -6270,7 +6952,7 @@ vm_object_page_op(
                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_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) {
@@ -6278,48 +6960,13 @@ vm_object_page_op(
                                PAGE_WAKEUP(dst_page);
                        }
                }
-
-               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 (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;
+                       *phys_entry = VM_PAGE_GET_PHYS_PAGE(dst_page);
                }
 
                break;
@@ -6346,17 +6993,23 @@ vm_object_range_op(
        vm_object_offset_t      offset_beg,
        vm_object_offset_t      offset_end,
        int                     ops,
-       int                     *range)
+       uint32_t                *range)
 {
         vm_object_offset_t     offset;
        vm_page_t               dst_page;
 
+       if (offset_end - offset_beg > (uint32_t) -1) {
+               /* range is too big and would overflow "*range" */
+               return KERN_INVALID_ARGUMENT;
+       } 
        if (object->resident_page_count == 0) {
                if (range) {
-                       if (ops & UPL_ROP_PRESENT)
+                       if (ops & UPL_ROP_PRESENT) {
                                *range = 0;
-                       else
-                               *range = offset_end - offset_beg;
+                       } else {
+                               *range = (uint32_t) (offset_end - offset_beg);
+                               assert(*range == (offset_end - offset_beg));
+                       }
                }
                return KERN_SUCCESS;
        }
@@ -6374,7 +7027,7 @@ vm_object_range_op(
                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
                                         */
@@ -6387,15 +7040,18 @@ vm_object_range_op(
                                         */
                                        continue;
                                }
+                               if (dst_page->laundry)
+                                       vm_pageout_steal_laundry(dst_page, FALSE);
+
                                if (dst_page->pmapped == TRUE)
-                                       pmap_disconnect(dst_page->phys_page);
+                                       pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(dst_page));
 
-                               vm_page_lock_queues();
-                               vm_page_free(dst_page);
-                               vm_page_unlock_queues();
+                               VM_PAGE_FREE(dst_page);
 
-                       } else if (ops & UPL_ROP_ABSENT)
-                               break;
+                       } else if ((ops & UPL_ROP_ABSENT)
+                                          && (!dst_page->absent || dst_page->busy)) {
+                               break;
+                       }
                } else if (ops & UPL_ROP_PRESENT)
                        break;
 
@@ -6406,13 +7062,65 @@ vm_object_range_op(
        if (range) {
                if (offset > offset_end)
                        offset = offset_end;
-               if(offset > offset_beg)
-                       *range = offset - offset_beg;
-               else *range=0;
+               if(offset > offset_beg) {
+                       *range = (uint32_t) (offset - offset_beg);
+                       assert(*range == (offset - offset_beg));
+               } else {
+                       *range = 0;
+               }
        }
        return KERN_SUCCESS;
 }
 
+/*
+ * 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;
+       }
+
+       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);
+
+       if (retval != KERN_SUCCESS) {
+               if (pager_object->private != clobbered_private) {
+                       vm_object_lock(pager_object);
+                       pager_object->private = clobbered_private;
+                       vm_object_unlock(pager_object);
+               }
+       }
+
+out:
+       return retval;
+}
 
 uint32_t scan_object_collision = 0;
 
@@ -6424,34 +7132,746 @@ vm_object_lock(vm_object_t object)
                mutex_pause(2);
        }
         lck_rw_lock_exclusive(&object->Lock);
+#if DEVELOPMENT || DEBUG
+       object->Lock_owner = current_thread();
+#endif
 }
 
 boolean_t
-vm_object_lock_try(vm_object_t object)
+vm_object_lock_avoid(vm_object_t object)
 {
         if (object == vm_pageout_scan_wants_object) {
                scan_object_collision++;
-               mutex_pause(2);
+               return TRUE;
+       }
+       return FALSE;
+}
+
+boolean_t
+_vm_object_lock_try(vm_object_t object)
+{
+       boolean_t       retval;
+
+       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)
+{
+       /*
+        * Called from hibernate path so check before blocking.
+        */
+       if (vm_object_lock_avoid(object) && ml_get_interrupts_enabled() && get_preemption_level()==0) {
+               mutex_pause(2);
        }
-       return (lck_rw_try_lock_exclusive(&object->Lock));
+       return _vm_object_lock_try(object);
 }
 
 void
 vm_object_lock_shared(vm_object_t object)
 {
-        if (object == vm_pageout_scan_wants_object) {
-               scan_object_collision++;
+        if (vm_object_lock_avoid(object)) {
                mutex_pause(2);
        }
        lck_rw_lock_shared(&object->Lock);
 }
 
+boolean_t
+vm_object_lock_yield_shared(vm_object_t object)
+{
+       boolean_t retval = FALSE, force_yield = FALSE;;
+
+       vm_object_lock_assert_shared(object);
+
+       force_yield = vm_object_lock_avoid(object);
+
+       retval = lck_rw_lock_yield_shared(&object->Lock, force_yield);
+
+       return (retval);
+}
+
 boolean_t
 vm_object_lock_try_shared(vm_object_t object)
 {
-        if (object == vm_pageout_scan_wants_object) {
-               scan_object_collision++;
+        if (vm_object_lock_avoid(object)) {
                mutex_pause(2);
        }
        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;
+       }
+#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;
+
+       object->wimg_bits = wimg_mode;
+
+       vm_object_change_wimg_mode_count++;
+}
+
+#if CONFIG_FREEZE
+
+/*
+ * This routine does the "relocation" of previously
+ * compressed pages belonging to this object that are
+ * residing in a number of compressed segments into
+ * a set of compressed segments dedicated to hold
+ * compressed pages belonging to this object.
+ */
+
+extern void *freezer_chead;
+extern char *freezer_compressor_scratch_buf;
+extern int c_freezer_compression_count;
+extern AbsoluteTime c_freezer_last_yield_ts;
+
+#define        MAX_FREE_BATCH  32
+#define FREEZER_DUTY_CYCLE_ON_MS       5
+#define FREEZER_DUTY_CYCLE_OFF_MS      5
+
+static int c_freezer_should_yield(void);
+
+
+static int
+c_freezer_should_yield()
+{
+       AbsoluteTime    cur_time;
+       uint64_t        nsecs;
+
+       assert(c_freezer_last_yield_ts);
+       clock_get_uptime(&cur_time);
+
+       SUB_ABSOLUTETIME(&cur_time, &c_freezer_last_yield_ts);
+       absolutetime_to_nanoseconds(cur_time, &nsecs);
+
+       if (nsecs > 1000 * 1000 * FREEZER_DUTY_CYCLE_ON_MS)
+               return (1);
+       return (0);
+}
+
+
+void
+vm_object_compressed_freezer_done()
+{
+       vm_compressor_finished_filling(&freezer_chead);
+}
+
+
+void
+vm_object_compressed_freezer_pageout(
+       vm_object_t object)
+{
+       vm_page_t                       p;
+       vm_page_t                       local_freeq = NULL;
+       int                             local_freed = 0;
+       kern_return_t                   retval = KERN_SUCCESS;
+       int                             obj_resident_page_count_snapshot = 0;
+
+       assert(object != VM_OBJECT_NULL);
+       assert(object->internal);
+
+       vm_object_lock(object);
+
+       if (!object->pager_initialized || object->pager == MEMORY_OBJECT_NULL)  {
+                       
+               if (!object->pager_initialized) {
+
+                       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;
+               }
+       }
+                       
+       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".
+                */
+               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;
+               }
+       }
+
+       /*
+        * 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.
+        */
+
+       obj_resident_page_count_snapshot = object->resident_page_count;
+
+       vm_object_activity_begin(object);
+
+       while ((obj_resident_page_count_snapshot--) && !vm_page_queue_empty(&object->memq)) {
+
+               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 {
+                               pmap_flags = PMAP_OPTIONS_COMPRESSOR_IFF_MODIFIED;
+                       }
+
+                       refmod_state = pmap_disconnect_options(VM_PAGE_GET_PHYS_PAGE(p), pmap_flags, NULL);
+                       if (refmod_state & VM_MEM_MODIFIED) {
+                               SET_PAGE_DIRTY(p, FALSE);
+                       }
+               }
+               
+               if (p->dirty == FALSE && p->precious == FALSE) {
+                       /*
+                        * Clean and non-precious page.
+                        */
+                       vm_page_unlock_queues();
+                       VM_PAGE_FREE(p);
+
+                       KERNEL_DEBUG(0xe0430004 | DBG_FUNC_END, object, local_freed, 2, 0, 0);
+                       continue;
+               }
+
+               if (p->laundry)
+                       vm_pageout_steal_laundry(p, TRUE);
+
+               vm_page_queues_remove(p, TRUE);
+
+               vm_page_unlock_queues();
+
+
+               /*
+                * 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.
+                */
+
+               vm_page_queue_remove(&object->memq, p, vm_page_t, listq);
+               vm_page_queue_enter(&object->memq, p, vm_page_t, listq);
+
+               /*
+                * 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.
+                */
+
+               p->busy = TRUE;
+
+               vm_object_activity_begin(object);
+
+               vm_object_unlock(object);
+
+               /*
+                * arg3 == FALSE  tells vm_pageout_compress_page that we don't hold the object lock and the pager may not be initialized.
+                */
+               if (vm_pageout_compress_page(&freezer_chead, freezer_compressor_scratch_buf, p, FALSE) == KERN_SUCCESS) {
+                       /*
+                        * page has already been un-tabled from the object via 'vm_page_remove'
+                        */
+                       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;
+                       }
+                       c_freezer_compression_count++;
+               }
+               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);
+       }
+
+       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 */
+
+
+void
+vm_object_pageout(
+       vm_object_t object)
+{
+       vm_page_t                       p, next;
+       struct  vm_pageout_queue        *iq;
+
+       if (!VM_CONFIG_COMPRESSOR_IS_PRESENT)
+               return;
+
+       iq = &vm_pageout_queue_internal;
+       
+       assert(object != VM_OBJECT_NULL );
+       
+       vm_object_lock(object);
+
+       if (!object->internal ||
+           object->terminating ||
+           !object->alive) {
+               vm_object_unlock(object);
+               return;
+       }
+
+       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;
+               }
+       }
+                       
+ReScan:        
+       next = (vm_page_t)vm_page_queue_first(&object->memq);
+
+       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->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;
+               }
+
+               /* Throw to the pageout queue */
+
+               vm_page_lockspin_queues();
+
+               if (vm_compressor_low_on_space()) {
+                       vm_page_unlock_queues();
+                       break;          
+               }
+
+               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);
+
+                       vm_object_lock(object);
+                       goto ReScan;
+               }
+
+               assert(!p->fictitious);
+               assert(!p->busy);
+               assert(!p->absent);
+               assert(!p->unusual);
+               assert(!p->error);
+               assert(!VM_PAGE_WIRED(p));
+               assert(!p->cleaning);
+
+               if (p->pmapped == TRUE) {
+                       int refmod_state;
+                       int pmap_options;
+
+                       /*
+                        * Tell pmap the page should be accounted
+                        * for as "compressed" if it's been modified.
+                        */
+                       pmap_options =
+                               PMAP_OPTIONS_COMPRESSOR_IFF_MODIFIED;
+                       if (p->dirty || p->precious) {
+                               /*
+                                * We already know it's been modified,
+                                * so tell pmap to account for it
+                                * as "compressed".
+                                */
+                               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 (!p->dirty && !p->precious) {
+                       vm_page_unlock_queues();
+                       VM_PAGE_FREE(p);
+                       continue;
+               }
+               vm_page_queues_remove(p, TRUE);
+
+               vm_pageout_cluster(p);
+               
+               vm_page_unlock_queues();
+       }
+       vm_object_unlock(object);
+}
+
+
+#if CONFIG_IOSCHED
+void
+vm_page_request_reprioritize(vm_object_t o, uint64_t blkno, uint32_t len, int prio)
+{
+       io_reprioritize_req_t   req;
+       struct vnode            *devvp = NULL;  
+
+       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;
+
+       /* Insert request into the reprioritization list */
+       IO_REPRIORITIZE_LIST_LOCK();
+       queue_enter(&io_reprioritize_list, req, io_reprioritize_req_t, io_reprioritize_list);
+       IO_REPRIORITIZE_LIST_UNLOCK();
+
+       /* Wakeup reprioritize thread */
+       IO_REPRIO_THREAD_WAKEUP();      
+
+       return;         
+}      
+
+void
+vm_decmp_upl_reprioritize(upl_t upl, int prio)
+{
+       int offset;
+       vm_object_t object;
+       io_reprioritize_req_t   req;
+       struct vnode            *devvp = NULL;
+       uint64_t                blkno;
+       uint32_t                len;
+       upl_t                   io_upl;
+       uint64_t                *io_upl_reprio_info;
+       int                     io_upl_size;
+
+       if ((upl->flags & UPL_TRACKED_BY_OBJECT) == 0 || (upl->flags & UPL_EXPEDITE_SUPPORTED) == 0)
+               return;
+
+       /* 
+        * We dont want to perform any allocations with the upl lock held since that might 
+        * result in a deadlock. If the system is low on memory, the pageout thread would 
+        * try to pageout stuff and might wait on this lock. If we are waiting for the memory to
+        * be freed up by the pageout thread, it would be a deadlock.
+        */
+
+
+       /* First step is just to get the size of the upl to find out how big the reprio info is */
+       if(!upl_try_lock(upl))
+               return;
+
+       if (upl->decmp_io_upl == NULL) {
+               /* The real I/O upl was destroyed by the time we came in here. Nothing to do. */
+               upl_unlock(upl);
+               return;
+       }
+
+       io_upl = upl->decmp_io_upl;
+       assert((io_upl->flags & UPL_DECMP_REAL_IO) != 0);
+       io_upl_size = io_upl->size;
+       upl_unlock(upl);
+       
+       /* 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;
+
+       /* Now again take the lock, recheck the state and grab out the required info */
+       if(!upl_try_lock(upl))
+               goto out;
+
+       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));
+
+       /* 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;
+       }
+
+       /* 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;
+       }
+
+       upl_unlock(upl);
+
+       /* Now we have all the information needed to do the expedite */
+
+       offset = 0;
+       while (offset < io_upl_size) {
+               blkno   = io_upl_reprio_info[(offset / PAGE_SIZE)] & UPL_REPRIO_INFO_MASK;
+               len     = (io_upl_reprio_info[(offset / PAGE_SIZE)] >> UPL_REPRIO_INFO_SHIFT) & UPL_REPRIO_INFO_MASK;   
+
+               /*
+                * This implementation may cause some spurious expedites due to the 
+                * fact that we dont cleanup the blkno & len from the upl_reprio_info 
+                * even after the I/O is complete. 
+                */
+               
+               if (blkno != 0 && len != 0) {
+                       /* Create the request for I/O reprioritization */
+                               req = (io_reprioritize_req_t)zalloc(io_reprioritize_req_zone);
+                       assert(req != NULL);
+                       req->blkno = blkno;
+                       req->len = len;
+                       req->priority = prio;
+                       req->devvp = devvp;
+
+                       /* Insert request into the reprioritization list */
+                       IO_REPRIORITIZE_LIST_LOCK();
+                       queue_enter(&io_reprioritize_list, req, io_reprioritize_req_t, io_reprioritize_list);
+                       IO_REPRIORITIZE_LIST_UNLOCK();          
+                       
+                       offset += len;
+               } else {
+                       offset += PAGE_SIZE;
+               }
+       }
+
+       /* Wakeup reprioritize thread */
+        IO_REPRIO_THREAD_WAKEUP();
+
+out:
+       kfree(io_upl_reprio_info, sizeof(uint64_t) * (io_upl_size / PAGE_SIZE));
+       return;
+}
+
+void
+vm_page_handle_prio_inversion(vm_object_t o, vm_page_t m)
+{
+       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;
+}      
+
+wait_result_t
+vm_page_sleep(vm_object_t o, vm_page_t m, int interruptible)
+{
+       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);
+       }
+       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;
+}
+
+static void
+io_reprioritize_thread(void *param __unused, wait_result_t wr __unused)
+{
+       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