]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/vm/vm_compressor_backing_store.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / osfmk / vm / vm_compressor_backing_store.c
index 4a2eb0feabcf3b4813eaef61d46d15cc753e1aef..01a41f9debc036996e0d23e0c72f05fbb6532d74 100644 (file)
@@ -2,7 +2,7 @@
  * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
 #include "vm_compressor_backing_store.h"
+#include <vm/vm_pageout.h>
 #include <vm/vm_protos.h>
 
 #include <IOKit/IOHibernatePrivate.h>
 
 #include <kern/policy_internal.h>
 
-boolean_t      compressor_store_stop_compaction = FALSE;
-boolean_t      vm_swapfile_create_needed = FALSE;
-boolean_t      vm_swapfile_gc_needed = FALSE;
+LCK_GRP_DECLARE(vm_swap_data_lock_grp, "vm_swap_data");
+LCK_MTX_EARLY_DECLARE(vm_swap_data_lock, &vm_swap_data_lock_grp);
 
-int            swapper_throttle = -1;
-boolean_t      swapper_throttle_inited = FALSE;
-uint64_t       vm_swapout_thread_id;
-
-uint64_t       vm_swap_put_failures = 0;
-uint64_t       vm_swap_get_failures = 0;
-int            vm_num_swap_files = 0;
-int            vm_num_pinned_swap_files = 0;
-int            vm_swapout_thread_processed_segments = 0;
-int            vm_swapout_thread_awakened = 0;
-int            vm_swapfile_create_thread_awakened = 0;
-int            vm_swapfile_create_thread_running = 0;
-int            vm_swapfile_gc_thread_awakened = 0;
-int            vm_swapfile_gc_thread_running = 0;
-
-int64_t                vm_swappin_avail = 0;
-boolean_t      vm_swappin_enabled = FALSE;
-unsigned int   vm_swapfile_total_segs_alloced = 0;
-unsigned int   vm_swapfile_total_segs_used = 0;
+#if defined(XNU_TARGET_OS_OSX)
+/*
+ * launchd explicitly turns ON swap later during boot on macOS devices.
+ */
+boolean_t       compressor_store_stop_compaction = TRUE;
+#else
+boolean_t       compressor_store_stop_compaction = FALSE;
+#endif
 
-char           swapfilename[MAX_SWAPFILENAME_LEN + 1] = SWAP_FILE_NAME;
+boolean_t       vm_swapfile_create_needed = FALSE;
+boolean_t       vm_swapfile_gc_needed = FALSE;
+
+int             vm_swapper_throttle = -1;
+uint64_t        vm_swapout_thread_id;
+
+uint64_t        vm_swap_put_failures = 0; /* Likely failed I/O. Data is still in memory. */
+uint64_t        vm_swap_get_failures = 0; /* Fatal */
+uint64_t        vm_swap_put_failures_no_swap_file = 0; /* Possibly not fatal because we might just need a new swapfile. */
+int             vm_num_swap_files_config = 0;
+int             vm_num_swap_files = 0;
+int             vm_num_pinned_swap_files = 0;
+int             vm_swapout_thread_processed_segments = 0;
+int             vm_swapout_thread_awakened = 0;
+bool            vm_swapout_thread_running = FALSE;
+int             vm_swapfile_create_thread_awakened = 0;
+int             vm_swapfile_create_thread_running = 0;
+int             vm_swapfile_gc_thread_awakened = 0;
+int             vm_swapfile_gc_thread_running = 0;
+
+int64_t         vm_swappin_avail = 0;
+boolean_t       vm_swappin_enabled = FALSE;
+unsigned int    vm_swapfile_total_segs_alloced = 0;
+unsigned int    vm_swapfile_total_segs_used = 0;
+
+char            swapfilename[MAX_SWAPFILENAME_LEN + 1] = SWAP_FILE_NAME;
 
 extern vm_map_t compressor_map;
 
 
-#define SWAP_READY     0x1     /* Swap file is ready to be used */
-#define SWAP_RECLAIM   0x2     /* Swap file is marked to be reclaimed */
-#define SWAP_WANTED    0x4     /* Swap file has waiters */
-#define SWAP_REUSE     0x8     /* Swap file is on the Q and has a name. Reuse after init-ing.*/
-#define SWAP_PINNED    0x10    /* Swap file is pinned (FusionDrive) */
-
-
-struct swapfile{
-       queue_head_t            swp_queue;      /* list of swap files */
-       char                    *swp_path;      /* saved pathname of swap file */
-       struct vnode            *swp_vp;        /* backing vnode */
-       uint64_t                swp_size;       /* size of this swap file */
-       uint8_t                 *swp_bitmap;    /* bitmap showing the alloced/freed slots in the swap file */
-       unsigned int            swp_pathlen;    /* length of pathname */
-       unsigned int            swp_nsegs;      /* #segments we can use */
-       unsigned int            swp_nseginuse;  /* #segments in use */
-       unsigned int            swp_index;      /* index of this swap file */
-       unsigned int            swp_flags;      /* state of swap file */
-       unsigned int            swp_free_hint;  /* offset of 1st free chunk */
-       unsigned int            swp_io_count;   /* count of outstanding I/Os */
-       c_segment_t             *swp_csegs;     /* back pointers to the c_segments. Used during swap reclaim. */
-
-       struct trim_list        *swp_delayed_trim_list_head;
-       unsigned int            swp_delayed_trim_count;
+#define SWAP_READY      0x1     /* Swap file is ready to be used */
+#define SWAP_RECLAIM    0x2     /* Swap file is marked to be reclaimed */
+#define SWAP_WANTED     0x4     /* Swap file has waiters */
+#define SWAP_REUSE      0x8     /* Swap file is on the Q and has a name. Reuse after init-ing.*/
+#define SWAP_PINNED     0x10    /* Swap file is pinned (FusionDrive) */
+
+
+struct swapfile {
+       queue_head_t            swp_queue;      /* list of swap files */
+       char                    *swp_path;      /* saved pathname of swap file */
+       struct vnode            *swp_vp;        /* backing vnode */
+       uint64_t                swp_size;       /* size of this swap file */
+       uint8_t                 *swp_bitmap;    /* bitmap showing the alloced/freed slots in the swap file */
+       unsigned int            swp_pathlen;    /* length of pathname */
+       unsigned int            swp_nsegs;      /* #segments we can use */
+       unsigned int            swp_nseginuse;  /* #segments in use */
+       unsigned int            swp_index;      /* index of this swap file */
+       unsigned int            swp_flags;      /* state of swap file */
+       unsigned int            swp_free_hint;  /* offset of 1st free chunk */
+       unsigned int            swp_io_count;   /* count of outstanding I/Os */
+       c_segment_t             *swp_csegs;     /* back pointers to the c_segments. Used during swap reclaim. */
+
+       struct trim_list        *swp_delayed_trim_list_head;
+       unsigned int            swp_delayed_trim_count;
 };
 
-queue_head_t   swf_global_queue;
-boolean_t      swp_trim_supported = FALSE;
+queue_head_t    swf_global_queue;
+boolean_t       swp_trim_supported = FALSE;
 
-extern clock_sec_t     dont_trim_until_ts;
-clock_sec_t            vm_swapfile_last_failed_to_create_ts = 0;
-clock_sec_t            vm_swapfile_last_successful_create_ts = 0;
-int                    vm_swapfile_can_be_created = FALSE;
-boolean_t              delayed_trim_handling_in_progress = FALSE;
+extern clock_sec_t      dont_trim_until_ts;
+clock_sec_t             vm_swapfile_last_failed_to_create_ts = 0;
+clock_sec_t             vm_swapfile_last_successful_create_ts = 0;
+int                     vm_swapfile_can_be_created = FALSE;
+boolean_t               delayed_trim_handling_in_progress = FALSE;
 
-boolean_t              hibernate_in_progress_with_pinned_swap = FALSE;
+boolean_t               hibernate_in_progress_with_pinned_swap = FALSE;
 
 static void vm_swapout_thread_throttle_adjust(void);
 static void vm_swap_free_now(struct swapfile *swf, uint64_t f_offset);
@@ -109,40 +123,46 @@ static void vm_swap_handle_delayed_trims(boolean_t);
 static void vm_swap_do_delayed_trim(struct swapfile *);
 static void vm_swap_wait_on_trim_handling_in_progress(void);
 
+extern int vnode_getwithref(struct vnode* vp);
+
+boolean_t vm_swap_force_defrag = FALSE, vm_swap_force_reclaim = FALSE;
+
+#if !XNU_TARGET_OS_OSX
 
-#if CONFIG_EMBEDDED
 /*
- * Only 1 swap file currently allowed.
+ * For CONFIG_FREEZE, we scale the c_segments_limit based on the
+ * number of swapfiles allowed. That increases wired memory overhead.
+ * So we want to keep the max swapfiles same on both DEV/RELEASE so
+ * that the memory overhead is similar for performance comparisons.
  */
-#define VM_MAX_SWAP_FILE_NUM           1
-#define        VM_SWAPFILE_DELAYED_TRIM_MAX    4
+#define VM_MAX_SWAP_FILE_NUM            5
+
+#define VM_SWAPFILE_DELAYED_TRIM_MAX    4
 
-#define        VM_SWAP_SHOULD_DEFRAGMENT()     (c_swappedout_sparse_count > (vm_swapfile_total_segs_used / 16) ? 1 : 0)
-#define VM_SWAP_SHOULD_RECLAIM()       FALSE
-#define VM_SWAP_SHOULD_ABORT_RECLAIM() FALSE
-#define VM_SWAP_SHOULD_PIN(_size)      FALSE
-#define VM_SWAP_SHOULD_CREATE(cur_ts)  ((vm_num_swap_files < VM_MAX_SWAP_FILE_NUM) && ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < (unsigned int)VM_SWAPFILE_HIWATER_SEGS) && \
-                                        ((cur_ts - vm_swapfile_last_failed_to_create_ts) > VM_SWAPFILE_DELAYED_CREATE) ? 1 : 0)
-#define VM_SWAP_SHOULD_TRIM(swf)       ((swf->swp_delayed_trim_count >= VM_SWAPFILE_DELAYED_TRIM_MAX) ? 1 : 0)
+#define VM_SWAP_SHOULD_DEFRAGMENT()     (((vm_swap_force_defrag == TRUE) || (c_swappedout_sparse_count > (vm_swapfile_total_segs_used / 16))) ? 1 : 0)
+#define VM_SWAP_SHOULD_PIN(_size)       FALSE
+#define VM_SWAP_SHOULD_CREATE(cur_ts)   ((vm_num_swap_files < vm_num_swap_files_config) && ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < (unsigned int)VM_SWAPFILE_HIWATER_SEGS) && \
+                                        ((cur_ts - vm_swapfile_last_failed_to_create_ts) > VM_SWAPFILE_DELAYED_CREATE) ? 1 : 0)
+#define VM_SWAP_SHOULD_TRIM(swf)        ((swf->swp_delayed_trim_count >= VM_SWAPFILE_DELAYED_TRIM_MAX) ? 1 : 0)
 
-#else /* CONFIG_EMBEDDED */
+#else /* !XNU_TARGET_OS_OSX */
 
-#define VM_MAX_SWAP_FILE_NUM           100
-#define        VM_SWAPFILE_DELAYED_TRIM_MAX    128
+#define VM_MAX_SWAP_FILE_NUM            100
+#define VM_SWAPFILE_DELAYED_TRIM_MAX    128
 
-#define        VM_SWAP_SHOULD_DEFRAGMENT()     (c_swappedout_sparse_count > (vm_swapfile_total_segs_used / 4) ? 1 : 0)
-#define VM_SWAP_SHOULD_RECLAIM()       (((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) >= SWAPFILE_RECLAIM_THRESHOLD_SEGS) ? 1 : 0)
-#define VM_SWAP_SHOULD_ABORT_RECLAIM() (((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) <= SWAPFILE_RECLAIM_MINIMUM_SEGS) ? 1 : 0)
-#define VM_SWAP_SHOULD_PIN(_size)      (vm_swappin_avail > 0 && vm_swappin_avail >= (int64_t)(_size))
-#define VM_SWAP_SHOULD_CREATE(cur_ts)  ((vm_num_swap_files < VM_MAX_SWAP_FILE_NUM) && ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < (unsigned int)VM_SWAPFILE_HIWATER_SEGS) && \
-                                        ((cur_ts - vm_swapfile_last_failed_to_create_ts) > VM_SWAPFILE_DELAYED_CREATE) ? 1 : 0)
-#define VM_SWAP_SHOULD_TRIM(swf)       ((swf->swp_delayed_trim_count >= VM_SWAPFILE_DELAYED_TRIM_MAX) ? 1 : 0)
+#define VM_SWAP_SHOULD_DEFRAGMENT()     (((vm_swap_force_defrag == TRUE) || (c_swappedout_sparse_count > (vm_swapfile_total_segs_used / 4))) ? 1 : 0)
+#define VM_SWAP_SHOULD_PIN(_size)       (vm_swappin_avail > 0 && vm_swappin_avail >= (int64_t)(_size))
+#define VM_SWAP_SHOULD_CREATE(cur_ts)   ((vm_num_swap_files < vm_num_swap_files_config) && ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < (unsigned int)VM_SWAPFILE_HIWATER_SEGS) && \
+                                        ((cur_ts - vm_swapfile_last_failed_to_create_ts) > VM_SWAPFILE_DELAYED_CREATE) ? 1 : 0)
+#define VM_SWAP_SHOULD_TRIM(swf)        ((swf->swp_delayed_trim_count >= VM_SWAPFILE_DELAYED_TRIM_MAX) ? 1 : 0)
 
-#endif /* CONFIG_EMBEDDED */
+#endif /* !XNU_TARGET_OS_OSX */
 
-#define        VM_SWAPFILE_DELAYED_CREATE      15
+#define VM_SWAP_SHOULD_RECLAIM()        (((vm_swap_force_reclaim == TRUE) || ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) >= SWAPFILE_RECLAIM_THRESHOLD_SEGS)) ? 1 : 0)
+#define VM_SWAP_SHOULD_ABORT_RECLAIM()  (((vm_swap_force_reclaim == FALSE) && ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) <= SWAPFILE_RECLAIM_MINIMUM_SEGS)) ? 1 : 0)
+#define VM_SWAPFILE_DELAYED_CREATE      15
 
-#define VM_SWAP_BUSY() ((c_swapout_count && (swapper_throttle == THROTTLE_LEVEL_COMPRESSOR_TIER1 || swapper_throttle == THROTTLE_LEVEL_COMPRESSOR_TIER0)) ? 1 : 0)
+#define VM_SWAP_BUSY()  ((c_swapout_count && (vm_swapper_throttle == THROTTLE_LEVEL_COMPRESSOR_TIER0)) ? 1 : 0)
 
 
 #if CHECKSUM_THE_SWAP
@@ -150,37 +170,35 @@ extern unsigned int hash_string(char *cp, int len);
 #endif
 
 #if RECORD_THE_COMPRESSED_DATA
-boolean_t      c_compressed_record_init_done = FALSE;
-int            c_compressed_record_write_error = 0;
-struct vnode   *c_compressed_record_vp = NULL;
-uint64_t       c_compressed_record_file_offset = 0;
-void   c_compressed_record_init(void);
-void   c_compressed_record_write(char *, int);
+boolean_t       c_compressed_record_init_done = FALSE;
+int             c_compressed_record_write_error = 0;
+struct vnode    *c_compressed_record_vp = NULL;
+uint64_t        c_compressed_record_file_offset = 0;
+void    c_compressed_record_init(void);
+void    c_compressed_record_write(char *, int);
 #endif
 
-extern void                    vm_pageout_io_throttle(void);
+extern void                     vm_pageout_io_throttle(void);
 
 static struct swapfile *vm_swapfile_for_handle(uint64_t);
 
 /*
  * Called with the vm_swap_data_lock held.
- */ 
+ */
 
 static struct swapfile *
-vm_swapfile_for_handle(uint64_t f_offset) 
+vm_swapfile_for_handle(uint64_t f_offset)
 {
-       
-       uint64_t                file_offset = 0;
-       unsigned int            swapfile_index = 0;
-       struct swapfile*        swf = NULL;
+       uint64_t                file_offset = 0;
+       unsigned int            swapfile_index = 0;
+       struct swapfile*        swf = NULL;
 
-       file_offset = (f_offset & SWAP_SLOT_MASK);      
+       file_offset = (f_offset & SWAP_SLOT_MASK);
        swapfile_index = (f_offset >> SWAP_DEVICE_SHIFT);
 
        swf = (struct swapfile*) queue_first(&swf_global_queue);
 
-       while(queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
-
+       while (queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
                if (swapfile_index == swf->swp_index) {
                        break;
                }
@@ -197,154 +215,152 @@ vm_swapfile_for_handle(uint64_t f_offset)
 
 #if ENCRYPTED_SWAP
 
-#include <libkern/crypto/aes.h>
-extern u_int32_t random(void); /* from <libkern/libkern.h> */
+#include <libkern/crypto/aesxts.h>
 
-#define SWAP_CRYPT_AES_KEY_SIZE 128     /* XXX 192 and 256 don't work ! */
+extern int cc_rand_generate(void *, size_t);     /* from libkern/cyrpto/rand.h> */
 
-boolean_t              swap_crypt_ctx_initialized;
-void                   swap_crypt_ctx_initialize(void);
+boolean_t       swap_crypt_initialized;
+void            swap_crypt_initialize(void);
 
-aes_ctx                        swap_crypt_ctx;
-const unsigned char     swap_crypt_null_iv[AES_BLOCK_SIZE] = {0xa, };
-uint32_t                swap_crypt_key[8]; /* big enough for a 256 key */
+symmetric_xts   xts_modectx;
+uint32_t        swap_crypt_key1[8];   /* big enough for a 256 bit random key */
+uint32_t        swap_crypt_key2[8];   /* big enough for a 256 bit random key */
 
-unsigned long          vm_page_encrypt_counter;
-unsigned long          vm_page_decrypt_counter;
+#if DEVELOPMENT || DEBUG
+boolean_t       swap_crypt_xts_tested = FALSE;
+unsigned char   swap_crypt_test_page_ref[4096] __attribute__((aligned(4096)));
+unsigned char   swap_crypt_test_page_encrypt[4096] __attribute__((aligned(4096)));
+unsigned char   swap_crypt_test_page_decrypt[4096] __attribute__((aligned(4096)));
+#endif /* DEVELOPMENT || DEBUG */
 
+unsigned long   vm_page_encrypt_counter;
+unsigned long   vm_page_decrypt_counter;
 
-#if DEBUG
-boolean_t              swap_crypt_ctx_tested = FALSE;
-unsigned char swap_crypt_test_page_ref[4096] __attribute__((aligned(4096)));
-unsigned char swap_crypt_test_page_encrypt[4096] __attribute__((aligned(4096)));
-unsigned char swap_crypt_test_page_decrypt[4096] __attribute__((aligned(4096)));
-#endif /* DEBUG */
 
-/*
- * Initialize the encryption context: key and key size.
- */
-void swap_crypt_ctx_initialize(void); /* forward */
 void
-swap_crypt_ctx_initialize(void)
+swap_crypt_initialize(void)
 {
-       unsigned int    i;
+       uint8_t  *enckey1, *enckey2;
+       int      keylen1, keylen2;
+       int      error;
+
+       assert(swap_crypt_initialized == FALSE);
+
+       keylen1 = sizeof(swap_crypt_key1);
+       enckey1 = (uint8_t *)&swap_crypt_key1;
+       keylen2 = sizeof(swap_crypt_key2);
+       enckey2 = (uint8_t *)&swap_crypt_key2;
+
+       error = cc_rand_generate((void *)enckey1, keylen1);
+       assert(!error);
+
+       error = cc_rand_generate((void *)enckey2, keylen2);
+       assert(!error);
+
+       error = xts_start(0, NULL, enckey1, keylen1, enckey2, keylen2, 0, 0, &xts_modectx);
+       assert(!error);
+
+       swap_crypt_initialized = TRUE;
+
+#if DEVELOPMENT || DEBUG
+       uint8_t *encptr;
+       uint8_t *decptr;
+       uint8_t *refptr;
+       uint8_t *iv;
+       uint64_t ivnum[2];
+       int size = 0;
+       int i    = 0;
+       int rc   = 0;
+
+       assert(swap_crypt_xts_tested == FALSE);
 
-       /*
-        * No need for locking to protect swap_crypt_ctx_initialized
-        * because the first use of encryption will come from the
-        * pageout thread (we won't pagein before there's been a pageout)
-        * and there's only one pageout thread.
-        */
-       if (swap_crypt_ctx_initialized == FALSE) {
-               for (i = 0;
-                    i < (sizeof (swap_crypt_key) /
-                         sizeof (swap_crypt_key[0]));
-                    i++) {
-                       swap_crypt_key[i] = random();
-               }
-               aes_encrypt_key((const unsigned char *) swap_crypt_key,
-                               SWAP_CRYPT_AES_KEY_SIZE,
-                               &swap_crypt_ctx.encrypt);
-               aes_decrypt_key((const unsigned char *) swap_crypt_key,
-                               SWAP_CRYPT_AES_KEY_SIZE,
-                               &swap_crypt_ctx.decrypt);
-               swap_crypt_ctx_initialized = TRUE;
-       }
-
-#if DEBUG
        /*
         * Validate the encryption algorithms.
+        *
+        * First initialize the test data.
         */
-       if (swap_crypt_ctx_tested == FALSE) {
-               /* initialize */
-               for (i = 0; i < 4096; i++) {
-                       swap_crypt_test_page_ref[i] = (char) i;
-               }
-               /* encrypt */
-               aes_encrypt_cbc(swap_crypt_test_page_ref,
-                               swap_crypt_null_iv,
-                               PAGE_SIZE / AES_BLOCK_SIZE,
-                               swap_crypt_test_page_encrypt,
-                               &swap_crypt_ctx.encrypt);
-               /* decrypt */
-               aes_decrypt_cbc(swap_crypt_test_page_encrypt,
-                               swap_crypt_null_iv,
-                               PAGE_SIZE / AES_BLOCK_SIZE,
-                               swap_crypt_test_page_decrypt,
-                               &swap_crypt_ctx.decrypt);
-               /* compare result with original */
-               for (i = 0; i < 4096; i ++) {
-                       if (swap_crypt_test_page_decrypt[i] !=
-                           swap_crypt_test_page_ref[i]) {
-                               panic("encryption test failed");
-                       }
+       for (i = 0; i < 4096; i++) {
+               swap_crypt_test_page_ref[i] = (char) i;
+       }
+       ivnum[0] = (uint64_t)0xaa;
+       ivnum[1] = 0;
+       iv = (uint8_t *)ivnum;
+
+       refptr = (uint8_t *)swap_crypt_test_page_ref;
+       encptr = (uint8_t *)swap_crypt_test_page_encrypt;
+       decptr = (uint8_t *)swap_crypt_test_page_decrypt;
+       size = 4096;
+
+       /* encrypt */
+       rc = xts_encrypt(refptr, size, encptr, iv, &xts_modectx);
+       assert(!rc);
+
+       /* compare result with original - should NOT match */
+       for (i = 0; i < 4096; i++) {
+               if (swap_crypt_test_page_encrypt[i] !=
+                   swap_crypt_test_page_ref[i]) {
+                       break;
                }
+       }
+       assert(i != 4096);
 
-               /* encrypt again */
-               aes_encrypt_cbc(swap_crypt_test_page_decrypt,
-                               swap_crypt_null_iv,
-                               PAGE_SIZE / AES_BLOCK_SIZE,
-                               swap_crypt_test_page_decrypt,
-                               &swap_crypt_ctx.encrypt);
-               /* decrypt in place */
-               aes_decrypt_cbc(swap_crypt_test_page_decrypt,
-                               swap_crypt_null_iv,
-                               PAGE_SIZE / AES_BLOCK_SIZE,
-                               swap_crypt_test_page_decrypt,
-                               &swap_crypt_ctx.decrypt);
-               for (i = 0; i < 4096; i ++) {
-                       if (swap_crypt_test_page_decrypt[i] !=
-                           swap_crypt_test_page_ref[i]) {
-                               panic("in place encryption test failed");
-                       }
-               }
+       /* decrypt */
+       rc = xts_decrypt(encptr, size, decptr, iv, &xts_modectx);
+       assert(!rc);
 
-               swap_crypt_ctx_tested = TRUE;
+       /* compare result with original */
+       for (i = 0; i < 4096; i++) {
+               if (swap_crypt_test_page_decrypt[i] !=
+                   swap_crypt_test_page_ref[i]) {
+                       panic("encryption test failed");
+               }
+       }
+       /* encrypt in place */
+       rc = xts_encrypt(decptr, size, decptr, iv, &xts_modectx);
+       assert(!rc);
+
+       /* decrypt in place */
+       rc = xts_decrypt(decptr, size, decptr, iv, &xts_modectx);
+       assert(!rc);
+
+       for (i = 0; i < 4096; i++) {
+               if (swap_crypt_test_page_decrypt[i] !=
+                   swap_crypt_test_page_ref[i]) {
+                       panic("in place encryption test failed");
+               }
        }
-#endif /* DEBUG */
+       swap_crypt_xts_tested = TRUE;
+#endif /* DEVELOPMENT || DEBUG */
 }
 
 
 void
 vm_swap_encrypt(c_segment_t c_seg)
 {
-       vm_offset_t     kernel_vaddr = 0;
-       uint64_t        size = 0;
-
-       union {
-               unsigned char   aes_iv[AES_BLOCK_SIZE];
-               void            *c_seg;
-       } encrypt_iv;
-       
-       assert(swap_crypt_ctx_initialized);
-       
+       uint8_t *ptr;
+       uint8_t *iv;
+       uint64_t ivnum[2];
+       int size = 0;
+       int rc   = 0;
+
+       if (swap_crypt_initialized == FALSE) {
+               swap_crypt_initialize();
+       }
+
 #if DEVELOPMENT || DEBUG
        C_SEG_MAKE_WRITEABLE(c_seg);
 #endif
-       bzero(&encrypt_iv.aes_iv[0], sizeof (encrypt_iv.aes_iv));
-
-       encrypt_iv.c_seg = (void*)c_seg;
-
-       /* encrypt the "initial vector" */
-       aes_encrypt_cbc((const unsigned char *) &encrypt_iv.aes_iv[0],
-                       swap_crypt_null_iv,
-                       1,
-                       &encrypt_iv.aes_iv[0],
-                       &swap_crypt_ctx.encrypt);
-
-       kernel_vaddr = (vm_offset_t) c_seg->c_store.c_buffer;
+       ptr = (uint8_t *)c_seg->c_store.c_buffer;
        size = round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset));
 
-       /*
-        * Encrypt the c_segment.
-        */
-       aes_encrypt_cbc((const unsigned char *) kernel_vaddr,
-                       &encrypt_iv.aes_iv[0],
-                       (unsigned int)(size / AES_BLOCK_SIZE),
-                       (unsigned char *) kernel_vaddr,
-                       &swap_crypt_ctx.encrypt);
+       ivnum[0] = (uint64_t)c_seg;
+       ivnum[1] = 0;
+       iv = (uint8_t *)ivnum;
 
-       vm_page_encrypt_counter += (size/PAGE_SIZE_64);
+       rc = xts_encrypt(ptr, size, ptr, iv, &xts_modectx);
+       assert(!rc);
+
+       vm_page_encrypt_counter += (size / PAGE_SIZE_64);
 
 #if DEVELOPMENT || DEBUG
        C_SEG_WRITE_PROTECT(c_seg);
@@ -354,50 +370,28 @@ vm_swap_encrypt(c_segment_t c_seg)
 void
 vm_swap_decrypt(c_segment_t c_seg)
 {
+       uint8_t *ptr;
+       uint8_t *iv;
+       uint64_t ivnum[2];
+       int size = 0;
+       int rc   = 0;
 
-       vm_offset_t     kernel_vaddr = 0;
-       uint64_t        size = 0;
-
-       union {
-               unsigned char   aes_iv[AES_BLOCK_SIZE];
-               void            *c_seg;
-       } decrypt_iv;
-       
-       
-       assert(swap_crypt_ctx_initialized);
+       assert(swap_crypt_initialized);
 
 #if DEVELOPMENT || DEBUG
        C_SEG_MAKE_WRITEABLE(c_seg);
 #endif
-       /*
-        * Prepare an "initial vector" for the decryption.
-        * It has to be the same as the "initial vector" we
-        * used to encrypt that page.
-        */
-       bzero(&decrypt_iv.aes_iv[0], sizeof (decrypt_iv.aes_iv));
-
-       decrypt_iv.c_seg = (void*)c_seg;
-
-       /* encrypt the "initial vector" */
-       aes_encrypt_cbc((const unsigned char *) &decrypt_iv.aes_iv[0],
-                       swap_crypt_null_iv,
-                       1,
-                       &decrypt_iv.aes_iv[0],
-                       &swap_crypt_ctx.encrypt);
-       
-       kernel_vaddr = (vm_offset_t) c_seg->c_store.c_buffer;
+       ptr = (uint8_t *)c_seg->c_store.c_buffer;
        size = round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset));
 
-       /*
-        * Decrypt the c_segment.
-        */
-       aes_decrypt_cbc((const unsigned char *) kernel_vaddr,
-                       &decrypt_iv.aes_iv[0],
-                       (unsigned int) (size / AES_BLOCK_SIZE),
-                       (unsigned char *) kernel_vaddr,
-                       &swap_crypt_ctx.decrypt);
+       ivnum[0] = (uint64_t)c_seg;
+       ivnum[1] = 0;
+       iv = (uint8_t *)ivnum;
+
+       rc = xts_decrypt(ptr, size, ptr, iv, &xts_modectx);
+       assert(!rc);
 
-       vm_page_decrypt_counter += (size/PAGE_SIZE_64);
+       vm_page_decrypt_counter += (size / PAGE_SIZE_64);
 
 #if DEVELOPMENT || DEBUG
        C_SEG_WRITE_PROTECT(c_seg);
@@ -409,62 +403,72 @@ vm_swap_decrypt(c_segment_t c_seg)
 void
 vm_compressor_swap_init()
 {
-       thread_t        thread = NULL;
-
-       lck_grp_attr_setdefault(&vm_swap_data_lock_grp_attr);
-       lck_grp_init(&vm_swap_data_lock_grp,
-                    "vm_swap_data",
-                    &vm_swap_data_lock_grp_attr);
-       lck_attr_setdefault(&vm_swap_data_lock_attr);
-       lck_mtx_init_ext(&vm_swap_data_lock,
-                        &vm_swap_data_lock_ext,
-                        &vm_swap_data_lock_grp,
-                        &vm_swap_data_lock_attr);
+       thread_t        thread = NULL;
 
        queue_init(&swf_global_queue);
 
-       
        if (kernel_thread_start_priority((thread_continue_t)vm_swapout_thread, NULL,
-                                        BASEPRI_VM, &thread) != KERN_SUCCESS) {
+           BASEPRI_VM, &thread) != KERN_SUCCESS) {
                panic("vm_swapout_thread: create failed");
        }
+       thread_set_thread_name(thread, "VM_swapout");
        vm_swapout_thread_id = thread->thread_id;
 
        thread_deallocate(thread);
 
        if (kernel_thread_start_priority((thread_continue_t)vm_swapfile_create_thread, NULL,
-                                BASEPRI_VM, &thread) != KERN_SUCCESS) {
+           BASEPRI_VM, &thread) != KERN_SUCCESS) {
                panic("vm_swapfile_create_thread: create failed");
        }
 
+       thread_set_thread_name(thread, "VM_swapfile_create");
        thread_deallocate(thread);
 
        if (kernel_thread_start_priority((thread_continue_t)vm_swapfile_gc_thread, NULL,
-                                BASEPRI_VM, &thread) != KERN_SUCCESS) {
+           BASEPRI_VM, &thread) != KERN_SUCCESS) {
                panic("vm_swapfile_gc_thread: create failed");
        }
+       thread_set_thread_name(thread, "VM_swapfile_gc");
+
+       /*
+        * Swapfile garbage collection will need to allocate memory
+        * to complete its swap reclaim and in-memory compaction.
+        * So allow it to dip into the reserved VM page pool.
+        */
+       thread_lock(thread);
+       thread->options |= TH_OPT_VMPRIV;
+       thread_unlock(thread);
+
        thread_deallocate(thread);
 
        proc_set_thread_policy_with_tid(kernel_task, thread->thread_id,
-                                       TASK_POLICY_INTERNAL, TASK_POLICY_IO, THROTTLE_LEVEL_COMPRESSOR_TIER2);
+           TASK_POLICY_INTERNAL, TASK_POLICY_IO, THROTTLE_LEVEL_COMPRESSOR_TIER2);
        proc_set_thread_policy_with_tid(kernel_task, thread->thread_id,
-                                       TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
 
-#if ENCRYPTED_SWAP
-       if (swap_crypt_ctx_initialized == FALSE) {
-               swap_crypt_ctx_initialize();
-       }
-#endif /* ENCRYPTED_SWAP */
-
-#if CONFIG_EMBEDDED
+#if !XNU_TARGET_OS_OSX
        /*
-        * dummy value until the swap file gets created 
-        * when we drive the first c_segment_t to the 
+        * dummy value until the swap file gets created
+        * when we drive the first c_segment_t to the
         * swapout queue... at that time we will
         * know the true size we have to work with
         */
        c_overage_swapped_limit = 16;
+#endif /* !XNU_TARGET_OS_OSX */
+
+       vm_num_swap_files_config = VM_MAX_SWAP_FILE_NUM;
+#if DEVELOPMENT || DEBUG
+       typeof(vm_num_swap_files_config) parsed_vm_max_num_swap_files = 0;
+       if (PE_parse_boot_argn("vm_max_num_swap_files", &parsed_vm_max_num_swap_files, sizeof(parsed_vm_max_num_swap_files))) {
+               if (parsed_vm_max_num_swap_files > 0) {
+                       vm_num_swap_files_config = parsed_vm_max_num_swap_files;
+               } else {
+                       printf("WARNING: Ignoring vm_max_num_swap_files=%d boot-arg. Value must be > 0\n", parsed_vm_max_num_swap_files);
+               }
+       }
 #endif
+       printf("Maximum number of VM swap files: %d\n", vm_num_swap_files_config);
+
        printf("VM Swap Subsystem is ON\n");
 }
 
@@ -491,17 +495,18 @@ c_compressed_record_write(char *buf, int size)
 #endif
 
 
-int            compaction_swapper_inited = 0;
+int             compaction_swapper_inited = 0;
 
 void
 vm_compaction_swapper_do_init(void)
 {
-       struct  vnode *vp;
-       char    *pathname;
-       int     namelen;
+       struct  vnode *vp;
+       char    *pathname;
+       int     namelen;
 
-       if (compaction_swapper_inited)
+       if (compaction_swapper_inited) {
                return;
+       }
 
        if (vm_compressor_mode != VM_PAGER_COMPRESSOR_WITH_SWAP) {
                compaction_swapper_inited = 1;
@@ -509,32 +514,48 @@ vm_compaction_swapper_do_init(void)
        }
        lck_mtx_lock(&vm_swap_data_lock);
 
-       if ( !compaction_swapper_inited) {
-
+       if (!compaction_swapper_inited) {
                namelen = (int)strlen(swapfilename) + SWAPFILENAME_INDEX_LEN + 1;
-               pathname = (char*)kalloc(namelen);
-               memset(pathname, 0, namelen);
+               pathname = kheap_alloc(KHEAP_TEMP, namelen, Z_WAITOK | Z_ZERO);
                snprintf(pathname, namelen, "%s%d", swapfilename, 0);
 
                vm_swapfile_open(pathname, &vp);
 
                if (vp) {
-                       
                        if (vnode_pager_isSSD(vp) == FALSE) {
-                               vm_compressor_minorcompact_threshold_divisor = 18;
-                               vm_compressor_majorcompact_threshold_divisor = 22;
-                               vm_compressor_unthrottle_threshold_divisor = 32;
+                               /*
+                                * swap files live on an HDD, so let's make sure to start swapping
+                                * much earlier since we're not worried about SSD write-wear and
+                                * we have so little write bandwidth to work with
+                                * these values were derived expermentially by running the performance
+                                * teams stock test for evaluating HDD performance against various
+                                * combinations and looking and comparing overall results.
+                                * Note that the > relationship between these 4 values must be maintained
+                                */
+                               if (vm_compressor_minorcompact_threshold_divisor_overridden == 0) {
+                                       vm_compressor_minorcompact_threshold_divisor = 15;
+                               }
+                               if (vm_compressor_majorcompact_threshold_divisor_overridden == 0) {
+                                       vm_compressor_majorcompact_threshold_divisor = 18;
+                               }
+                               if (vm_compressor_unthrottle_threshold_divisor_overridden == 0) {
+                                       vm_compressor_unthrottle_threshold_divisor = 24;
+                               }
+                               if (vm_compressor_catchup_threshold_divisor_overridden == 0) {
+                                       vm_compressor_catchup_threshold_divisor = 30;
+                               }
                        }
-#if !CONFIG_EMBEDDED
+#if XNU_TARGET_OS_OSX
                        vnode_setswapmount(vp);
                        vm_swappin_avail = vnode_getswappin_avail(vp);
 
-                       if (vm_swappin_avail)
+                       if (vm_swappin_avail) {
                                vm_swappin_enabled = TRUE;
-#endif
+                       }
+#endif /* XNU_TARGET_OS_OSX */
                        vm_swapfile_close((uint64_t)pathname, vp);
                }
-               kfree(pathname, namelen);
+               kheap_free(KHEAP_TEMP, pathname, namelen);
 
                compaction_swapper_inited = 1;
        }
@@ -542,18 +563,28 @@ vm_compaction_swapper_do_init(void)
 }
 
 
-
 void
-vm_swap_consider_defragmenting()
+vm_swap_consider_defragmenting(int flags)
 {
-       if (compressor_store_stop_compaction == FALSE && !VM_SWAP_BUSY() &&
-           (VM_SWAP_SHOULD_DEFRAGMENT() || VM_SWAP_SHOULD_RECLAIM())) {
+       boolean_t force_defrag = (flags & VM_SWAP_FLAGS_FORCE_DEFRAG);
+       boolean_t force_reclaim = (flags & VM_SWAP_FLAGS_FORCE_RECLAIM);
 
-               if (!vm_swapfile_gc_thread_running) {
+       if (compressor_store_stop_compaction == FALSE && !VM_SWAP_BUSY() &&
+           (force_defrag || force_reclaim || VM_SWAP_SHOULD_DEFRAGMENT() || VM_SWAP_SHOULD_RECLAIM())) {
+               if (!vm_swapfile_gc_thread_running || force_defrag || force_reclaim) {
                        lck_mtx_lock(&vm_swap_data_lock);
 
-                       if (!vm_swapfile_gc_thread_running)
+                       if (force_defrag) {
+                               vm_swap_force_defrag = TRUE;
+                       }
+
+                       if (force_reclaim) {
+                               vm_swap_force_reclaim = TRUE;
+                       }
+
+                       if (!vm_swapfile_gc_thread_running) {
                                thread_wakeup((event_t) &vm_swapfile_gc_needed);
+                       }
 
                        lck_mtx_unlock(&vm_swap_data_lock);
                }
@@ -566,11 +597,21 @@ int vm_swap_defragment_swapin = 0;
 int vm_swap_defragment_free = 0;
 int vm_swap_defragment_busy = 0;
 
+#if CONFIG_FREEZE
+extern uint32_t c_segment_pages_compressed_incore;
+extern uint32_t c_segment_pages_compressed_nearing_limit;
+extern uint32_t c_segment_count;
+extern uint32_t c_segments_nearing_limit;
+
+boolean_t       memorystatus_kill_on_VM_compressor_space_shortage(boolean_t);
+
+extern bool freezer_incore_cseg_acct;
+#endif /* CONFIG_FREEZE */
 
 static void
 vm_swap_defragment()
 {
-       c_segment_t     c_seg;
+       c_segment_t     c_seg;
 
        /*
         * have to grab the master lock w/o holding
@@ -579,9 +620,8 @@ vm_swap_defragment()
        PAGE_REPLACEMENT_DISALLOWED(TRUE);
 
        lck_mtx_lock_spin_always(c_list_lock);
-       
+
        while (!queue_empty(&c_swappedout_sparse_list_head)) {
-               
                if (compressor_store_stop_compaction == TRUE || VM_SWAP_BUSY()) {
                        vm_swap_defragment_yielded++;
                        break;
@@ -620,18 +660,31 @@ vm_swap_defragment()
                } else {
                        lck_mtx_unlock_always(c_list_lock);
 
-                       if (c_seg_swapin(c_seg, TRUE, FALSE) == 0)
+#if CONFIG_FREEZE
+                       if (freezer_incore_cseg_acct) {
+                               if ((c_seg->c_slots_used + c_segment_pages_compressed_incore) >= c_segment_pages_compressed_nearing_limit) {
+                                       memorystatus_kill_on_VM_compressor_space_shortage(TRUE /* async */);
+                               }
+
+                               uint32_t incore_seg_count = c_segment_count - c_swappedout_count - c_swappedout_sparse_count;
+                               if ((incore_seg_count + 1) >= c_segments_nearing_limit) {
+                                       memorystatus_kill_on_VM_compressor_space_shortage(TRUE /* async */);
+                               }
+                       }
+#endif /* CONFIG_FREEZE */
+                       if (c_seg_swapin(c_seg, TRUE, FALSE) == 0) {
                                lck_mtx_unlock_always(&c_seg->c_lock);
+                       }
 
                        vm_swap_defragment_swapin++;
                }
                PAGE_REPLACEMENT_DISALLOWED(FALSE);
-               
+
                vm_pageout_io_throttle();
 
                /*
                 * because write waiters have privilege over readers,
-                * dropping and immediately retaking the master lock will 
+                * dropping and immediately retaking the master lock will
                 * still allow any thread waiting to acquire the
                 * master lock exclusively an opportunity to take it
                 */
@@ -649,8 +702,8 @@ vm_swap_defragment()
 static void
 vm_swapfile_create_thread(void)
 {
-       clock_sec_t     sec;
-       clock_nsec_t    nsec;
+       clock_sec_t     sec;
+       clock_nsec_t    nsec;
 
        current_thread()->options |= TH_OPT_VMPRIV;
 
@@ -668,34 +721,45 @@ vm_swapfile_create_thread(void)
 
                lck_mtx_lock(&vm_swap_data_lock);
 
-               if (hibernate_in_progress_with_pinned_swap == TRUE)
+               if (hibernate_in_progress_with_pinned_swap == TRUE) {
                        break;
+               }
+
+               if (compressor_store_stop_compaction == TRUE) {
+                       break;
+               }
 
                clock_get_system_nanotime(&sec, &nsec);
 
-               if (VM_SWAP_SHOULD_CREATE(sec) == 0)
+               if (VM_SWAP_SHOULD_CREATE(sec) == 0) {
                        break;
+               }
 
                lck_mtx_unlock(&vm_swap_data_lock);
 
                if (vm_swap_create_file() == FALSE) {
                        vm_swapfile_last_failed_to_create_ts = sec;
                        HIBLOG("vm_swap_create_file failed @ %lu secs\n", (unsigned long)sec);
-
-               } else
+               } else {
                        vm_swapfile_last_successful_create_ts = sec;
+               }
        }
        vm_swapfile_create_thread_running = 0;
 
-       if (hibernate_in_progress_with_pinned_swap == TRUE)
+       if (hibernate_in_progress_with_pinned_swap == TRUE) {
                thread_wakeup((event_t)&hibernate_in_progress_with_pinned_swap);
+       }
+
+       if (compressor_store_stop_compaction == TRUE) {
+               thread_wakeup((event_t)&compressor_store_stop_compaction);
+       }
 
        assert_wait((event_t)&vm_swapfile_create_needed, THREAD_UNINT);
 
        lck_mtx_unlock(&vm_swap_data_lock);
 
        thread_block((thread_continue_t)vm_swapfile_create_thread);
-       
+
        /* NOTREACHED */
 }
 
@@ -708,22 +772,21 @@ hibernate_pin_swap(boolean_t start)
        vm_compaction_swapper_do_init();
 
        if (start == FALSE) {
-
                lck_mtx_lock(&vm_swap_data_lock);
                hibernate_in_progress_with_pinned_swap = FALSE;
                lck_mtx_unlock(&vm_swap_data_lock);
 
-               return (KERN_SUCCESS);
+               return KERN_SUCCESS;
+       }
+       if (vm_swappin_enabled == FALSE) {
+               return KERN_SUCCESS;
        }
-       if (vm_swappin_enabled == FALSE)
-               return (KERN_SUCCESS);
 
        lck_mtx_lock(&vm_swap_data_lock);
 
        hibernate_in_progress_with_pinned_swap = TRUE;
-               
-       while (vm_swapfile_create_thread_running || vm_swapfile_gc_thread_running) {
 
+       while (vm_swapfile_create_thread_running || vm_swapfile_gc_thread_running) {
                assert_wait((event_t)&hibernate_in_progress_with_pinned_swap, THREAD_UNINT);
 
                lck_mtx_unlock(&vm_swap_data_lock);
@@ -737,159 +800,293 @@ hibernate_pin_swap(boolean_t start)
                lck_mtx_unlock(&vm_swap_data_lock);
 
                HIBLOG("hibernate_pin_swap failed - vm_num_swap_files = %d, vm_num_pinned_swap_files = %d\n",
-                      vm_num_swap_files, vm_num_pinned_swap_files);
-               return (KERN_FAILURE);
+                   vm_num_swap_files, vm_num_pinned_swap_files);
+               return KERN_FAILURE;
        }
        lck_mtx_unlock(&vm_swap_data_lock);
 
        while (VM_SWAP_SHOULD_PIN(MAX_SWAP_FILE_SIZE)) {
-               if (vm_swap_create_file() == FALSE)
+               if (vm_swap_create_file() == FALSE) {
                        break;
+               }
        }
-       return (KERN_SUCCESS);
+       return KERN_SUCCESS;
 }
 #endif
 
 static void
 vm_swapfile_gc_thread(void)
-
 {
-       boolean_t       need_defragment;
-       boolean_t       need_reclaim;
+       boolean_t       need_defragment;
+       boolean_t       need_reclaim;
 
        vm_swapfile_gc_thread_awakened++;
        vm_swapfile_gc_thread_running = 1;
 
        while (TRUE) {
-
                lck_mtx_lock(&vm_swap_data_lock);
-               
-               if (hibernate_in_progress_with_pinned_swap == TRUE)
+
+               if (hibernate_in_progress_with_pinned_swap == TRUE) {
                        break;
+               }
 
-               if (VM_SWAP_BUSY() || compressor_store_stop_compaction == TRUE)
+               if (VM_SWAP_BUSY() || compressor_store_stop_compaction == TRUE) {
                        break;
+               }
 
                need_defragment = FALSE;
                need_reclaim = FALSE;
 
-               if (VM_SWAP_SHOULD_DEFRAGMENT())
+               if (VM_SWAP_SHOULD_DEFRAGMENT()) {
                        need_defragment = TRUE;
+               }
 
                if (VM_SWAP_SHOULD_RECLAIM()) {
                        need_defragment = TRUE;
                        need_reclaim = TRUE;
                }
-               if (need_defragment == FALSE && need_reclaim == FALSE)
+               if (need_defragment == FALSE && need_reclaim == FALSE) {
                        break;
+               }
+
+               vm_swap_force_defrag = FALSE;
+               vm_swap_force_reclaim = FALSE;
 
                lck_mtx_unlock(&vm_swap_data_lock);
 
-               if (need_defragment == TRUE)
+               if (need_defragment == TRUE) {
                        vm_swap_defragment();
-               if (need_reclaim == TRUE)
+               }
+               if (need_reclaim == TRUE) {
                        vm_swap_reclaim();
+               }
        }
        vm_swapfile_gc_thread_running = 0;
 
-       if (hibernate_in_progress_with_pinned_swap == TRUE)
+       if (hibernate_in_progress_with_pinned_swap == TRUE) {
                thread_wakeup((event_t)&hibernate_in_progress_with_pinned_swap);
+       }
+
+       if (compressor_store_stop_compaction == TRUE) {
+               thread_wakeup((event_t)&compressor_store_stop_compaction);
+       }
 
        assert_wait((event_t)&vm_swapfile_gc_needed, THREAD_UNINT);
 
        lck_mtx_unlock(&vm_swap_data_lock);
 
        thread_block((thread_continue_t)vm_swapfile_gc_thread);
-       
+
        /* NOTREACHED */
 }
 
 
 
-int      swapper_entered_T0 = 0;
-int      swapper_entered_T1 = 0;
-int      swapper_entered_T2 = 0;
+#define   VM_SWAPOUT_LIMIT_T2P  4
+#define   VM_SWAPOUT_LIMIT_T1P  4
+#define   VM_SWAPOUT_LIMIT_T0P  6
+#define   VM_SWAPOUT_LIMIT_T0   8
+#define   VM_SWAPOUT_LIMIT_MAX  8
+
+#define   VM_SWAPOUT_START      0
+#define   VM_SWAPOUT_T2_PASSIVE 1
+#define   VM_SWAPOUT_T1_PASSIVE 2
+#define   VM_SWAPOUT_T0_PASSIVE 3
+#define   VM_SWAPOUT_T0         4
+
+int vm_swapout_state = VM_SWAPOUT_START;
+int vm_swapout_limit = 1;
+
+int vm_swapper_entered_T0  = 0;
+int vm_swapper_entered_T0P = 0;
+int vm_swapper_entered_T1P = 0;
+int vm_swapper_entered_T2P = 0;
+
 
 static void
 vm_swapout_thread_throttle_adjust(void)
 {
-       int swapper_throttle_new;
+       switch (vm_swapout_state) {
+       case VM_SWAPOUT_START:
 
-       if (swapper_throttle_inited == FALSE) {
-               /*
-                * force this thread to be set to the correct
-                * throttling tier
-                */
-               swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER2;
-               swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER1;
-               swapper_throttle_inited = TRUE;
-               swapper_entered_T2++;
-               goto done;
-       }
-       swapper_throttle_new = swapper_throttle;
+               vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER2;
+               vm_swapper_entered_T2P++;
+
+               proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                   TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+               proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                   TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+               vm_swapout_limit = VM_SWAPOUT_LIMIT_T2P;
+               vm_swapout_state = VM_SWAPOUT_T2_PASSIVE;
+
+               break;
 
+       case VM_SWAPOUT_T2_PASSIVE:
 
-       switch(swapper_throttle) {
+               if (SWAPPER_NEEDS_TO_UNTHROTTLE()) {
+                       vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER0;
+                       vm_swapper_entered_T0P++;
 
-       case THROTTLE_LEVEL_COMPRESSOR_TIER2:
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T0P;
+                       vm_swapout_state = VM_SWAPOUT_T0_PASSIVE;
 
-               if (SWAPPER_NEEDS_TO_UNTHROTTLE() || swapout_target_age || hibernate_flushing == TRUE) {
-                       swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER1;
-                       swapper_entered_T1++;
                        break;
                }
+               if (swapout_target_age || hibernate_flushing == TRUE) {
+                       vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER1;
+                       vm_swapper_entered_T1P++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T1P;
+                       vm_swapout_state = VM_SWAPOUT_T1_PASSIVE;
+               }
                break;
 
-       case THROTTLE_LEVEL_COMPRESSOR_TIER1:
+       case VM_SWAPOUT_T1_PASSIVE:
+
+               if (SWAPPER_NEEDS_TO_UNTHROTTLE()) {
+                       vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER0;
+                       vm_swapper_entered_T0P++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T0P;
+                       vm_swapout_state = VM_SWAPOUT_T0_PASSIVE;
 
-               if (VM_PAGEOUT_SCAN_NEEDS_TO_THROTTLE()) {
-                       swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER0;
-                       swapper_entered_T0++;
                        break;
                }
-               if (COMPRESSOR_NEEDS_TO_SWAP() == 0 && swapout_target_age == 0 && hibernate_flushing == FALSE) {
-                       swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER2;
-                       swapper_entered_T2++;
-                       break;
+               if (swapout_target_age == 0 && hibernate_flushing == FALSE) {
+                       vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER2;
+                       vm_swapper_entered_T2P++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T2P;
+                       vm_swapout_state = VM_SWAPOUT_T2_PASSIVE;
                }
                break;
 
-       case THROTTLE_LEVEL_COMPRESSOR_TIER0:
+       case VM_SWAPOUT_T0_PASSIVE:
+
+               if (SWAPPER_NEEDS_TO_RETHROTTLE()) {
+                       vm_swapper_throttle = THROTTLE_LEVEL_COMPRESSOR_TIER2;
+                       vm_swapper_entered_T2P++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_IO, vm_swapper_throttle);
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T2P;
+                       vm_swapout_state = VM_SWAPOUT_T2_PASSIVE;
 
-               if (COMPRESSOR_NEEDS_TO_SWAP() == 0) {
-                       swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER2;
-                       swapper_entered_T2++;
                        break;
                }
-               if (SWAPPER_NEEDS_TO_UNTHROTTLE() == 0) {
-                       swapper_throttle_new = THROTTLE_LEVEL_COMPRESSOR_TIER1;
-                       swapper_entered_T1++;
-                       break;
+               if (SWAPPER_NEEDS_TO_CATCHUP()) {
+                       vm_swapper_entered_T0++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_DISABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T0;
+                       vm_swapout_state = VM_SWAPOUT_T0;
+               }
+               break;
+
+       case VM_SWAPOUT_T0:
+
+               if (SWAPPER_HAS_CAUGHTUP()) {
+                       vm_swapper_entered_T0P++;
+
+                       proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
+                           TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+                       vm_swapout_limit = VM_SWAPOUT_LIMIT_T0P;
+                       vm_swapout_state = VM_SWAPOUT_T0_PASSIVE;
                }
                break;
        }
-done:
-       if (swapper_throttle != swapper_throttle_new) {
-               proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
-                                               TASK_POLICY_INTERNAL, TASK_POLICY_IO, swapper_throttle_new);
-               proc_set_thread_policy_with_tid(kernel_task, vm_swapout_thread_id,
-                                               TASK_POLICY_INTERNAL, TASK_POLICY_PASSIVE_IO, TASK_POLICY_ENABLE);
+}
+
+int vm_swapout_found_empty = 0;
+
+struct swapout_io_completion vm_swapout_ctx[VM_SWAPOUT_LIMIT_MAX];
+
+int vm_swapout_soc_busy = 0;
+int vm_swapout_soc_done = 0;
+
+
+static struct swapout_io_completion *
+vm_swapout_find_free_soc(void)
+{
+       int      i;
+
+       for (i = 0; i < VM_SWAPOUT_LIMIT_MAX; i++) {
+               if (vm_swapout_ctx[i].swp_io_busy == 0) {
+                       return &vm_swapout_ctx[i];
+               }
+       }
+       assert(vm_swapout_soc_busy == VM_SWAPOUT_LIMIT_MAX);
 
-               swapper_throttle = swapper_throttle_new;
+       return NULL;
+}
+
+static struct swapout_io_completion *
+vm_swapout_find_done_soc(void)
+{
+       int      i;
+
+       if (vm_swapout_soc_done) {
+               for (i = 0; i < VM_SWAPOUT_LIMIT_MAX; i++) {
+                       if (vm_swapout_ctx[i].swp_io_done) {
+                               return &vm_swapout_ctx[i];
+                       }
+               }
        }
+       return NULL;
 }
 
+static void
+vm_swapout_complete_soc(struct swapout_io_completion *soc)
+{
+       kern_return_t  kr;
+
+       if (soc->swp_io_error) {
+               kr = KERN_FAILURE;
+       } else {
+               kr = KERN_SUCCESS;
+       }
+
+       lck_mtx_unlock_always(c_list_lock);
+
+       vm_swap_put_finish(soc->swp_swf, &soc->swp_f_offset, soc->swp_io_error, TRUE /*drop iocount*/);
+       vm_swapout_finish(soc->swp_c_seg, soc->swp_f_offset, soc->swp_c_size, kr);
+
+       lck_mtx_lock_spin_always(c_list_lock);
+
+       soc->swp_io_done = 0;
+       soc->swp_io_busy = 0;
+
+       vm_swapout_soc_busy--;
+       vm_swapout_soc_done--;
+}
 
-int vm_swapout_found_empty = 0;
 
 static void
 vm_swapout_thread(void)
 {
-       uint64_t        f_offset = 0;
-       uint32_t        size = 0;
-       c_segment_t     c_seg = NULL;
-       kern_return_t   kr = KERN_SUCCESS;
-       vm_offset_t     addr = 0;
+       uint32_t        size = 0;
+       c_segment_t     c_seg = NULL;
+       kern_return_t   kr = KERN_SUCCESS;
+       struct swapout_io_completion *soc;
 
        current_thread()->options |= TH_OPT_VMPRIV;
 
@@ -897,8 +1094,9 @@ vm_swapout_thread(void)
 
        lck_mtx_lock_spin_always(c_list_lock);
 
-       while (!queue_empty(&c_swapout_list_head)) {
-               
+       vm_swapout_thread_running = TRUE;
+again:
+       while (!queue_empty(&c_swapout_list_head) && vm_swapout_soc_busy < vm_swapout_limit && !compressor_store_stop_compaction) {
                c_seg = (c_segment_t)queue_first(&c_swapout_list_head);
 
                lck_mtx_lock_spin_always(&c_seg->c_lock);
@@ -917,12 +1115,13 @@ vm_swapout_thread(void)
                vm_swapout_thread_processed_segments++;
 
                size = round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset));
-               
+
                if (size == 0) {
                        assert(c_seg->c_bytes_used == 0);
 
-                       if (!c_seg->c_on_minorcompact_q)
+                       if (!c_seg->c_on_minorcompact_q) {
                                c_seg_need_delayed_compaction(c_seg, TRUE);
+                       }
 
                        c_seg_switch_state(c_seg, C_IS_EMPTY, FALSE);
                        lck_mtx_unlock_always(&c_seg->c_lock);
@@ -934,14 +1133,13 @@ vm_swapout_thread(void)
                C_SEG_BUSY(c_seg);
                c_seg->c_busy_swapping = 1;
 
-               lck_mtx_unlock_always(c_list_lock);
-
-               addr = (vm_offset_t) c_seg->c_store.c_buffer;
+               c_seg_switch_state(c_seg, C_ON_SWAPIO_Q, FALSE);
 
+               lck_mtx_unlock_always(c_list_lock);
                lck_mtx_unlock_always(&c_seg->c_lock);
 
-#if CHECKSUM_THE_SWAP  
-               c_seg->cseg_hash = hash_string((char*)addr, (int)size);
+#if CHECKSUM_THE_SWAP
+               c_seg->cseg_hash = hash_string((char *)c_seg->c_store.c_buffer, (int)size);
                c_seg->cseg_swap_size = size;
 #endif /* CHECKSUM_THE_SWAP */
 
@@ -949,88 +1147,183 @@ vm_swapout_thread(void)
                vm_swap_encrypt(c_seg);
 #endif /* ENCRYPTED_SWAP */
 
-               vm_swapout_thread_throttle_adjust();
-
-               kr = vm_swap_put((vm_offset_t) addr, &f_offset, size, c_seg);
-
-               PAGE_REPLACEMENT_DISALLOWED(TRUE);
-
-               if (kr == KERN_SUCCESS) {
-                       kernel_memory_depopulate(compressor_map, (vm_offset_t) addr, size, KMA_COMPRESSOR);
-               }
-#if ENCRYPTED_SWAP
-               else {
-                       vm_swap_decrypt(c_seg);
-               }
-#endif /* ENCRYPTED_SWAP */
-               lck_mtx_lock_spin_always(c_list_lock);
-               lck_mtx_lock_spin_always(&c_seg->c_lock);
+               soc = vm_swapout_find_free_soc();
+               assert(soc);
 
-               if (kr == KERN_SUCCESS) {
-                       int             new_state = C_ON_SWAPPEDOUT_Q;
-                       boolean_t       insert_head = FALSE;
+               soc->swp_upl_ctx.io_context = (void *)soc;
+               soc->swp_upl_ctx.io_done = (void *)vm_swapout_iodone;
+               soc->swp_upl_ctx.io_error = 0;
 
-                       if (hibernate_flushing == TRUE) {
-                               if (c_seg->c_generation_id >= first_c_segment_to_warm_generation_id &&
-                                   c_seg->c_generation_id <= last_c_segment_to_warm_generation_id)
-                                       insert_head = TRUE;
-                       } else if (C_SEG_ONDISK_IS_SPARSE(c_seg))
-                               new_state = C_ON_SWAPPEDOUTSPARSE_Q;
+               kr = vm_swap_put((vm_offset_t)c_seg->c_store.c_buffer, &soc->swp_f_offset, size, c_seg, soc);
 
-                       c_seg_switch_state(c_seg, new_state, insert_head);
+               if (kr != KERN_SUCCESS) {
+                       if (soc->swp_io_done) {
+                               lck_mtx_lock_spin_always(c_list_lock);
 
-                       c_seg->c_store.c_swap_handle = f_offset;
+                               soc->swp_io_done = 0;
+                               vm_swapout_soc_done--;
 
-                       VM_STAT_INCR_BY(swapouts, size >> PAGE_SHIFT);
-                       
-                       if (c_seg->c_bytes_used)
-                               OSAddAtomic64(-c_seg->c_bytes_used, &compressor_bytes_used);
-               } else {
-                       if (c_seg->c_overage_swap == TRUE) {
-                               c_seg->c_overage_swap = FALSE;
-                               c_overage_swapped_count--;
+                               lck_mtx_unlock_always(c_list_lock);
                        }
-                       c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
+                       vm_swapout_finish(c_seg, soc->swp_f_offset, size, kr);
+               } else {
+                       soc->swp_io_busy = 1;
+                       vm_swapout_soc_busy++;
+               }
 
-                       if (!c_seg->c_on_minorcompact_q && C_SEG_UNUSED_BYTES(c_seg) >= PAGE_SIZE)
-                               c_seg_need_delayed_compaction(c_seg, TRUE);
+c_seg_is_empty:
+               if (c_swapout_count == 0) {
+                       vm_swap_consider_defragmenting(VM_SWAP_FLAGS_NONE);
                }
-               assert(c_seg->c_busy_swapping);
-               assert(c_seg->c_busy);
 
-               c_seg->c_busy_swapping = 0;
+               lck_mtx_lock_spin_always(c_list_lock);
+
+               while ((soc = vm_swapout_find_done_soc())) {
+                       vm_swapout_complete_soc(soc);
+               }
                lck_mtx_unlock_always(c_list_lock);
 
-               C_SEG_WAKEUP_DONE(c_seg);
-               lck_mtx_unlock_always(&c_seg->c_lock);
+               vm_swapout_thread_throttle_adjust();
 
-               PAGE_REPLACEMENT_DISALLOWED(FALSE);
+               lck_mtx_lock_spin_always(c_list_lock);
+       }
+       while ((soc = vm_swapout_find_done_soc())) {
+               vm_swapout_complete_soc(soc);
+       }
+       lck_mtx_unlock_always(c_list_lock);
 
-               vm_pageout_io_throttle();
-c_seg_is_empty:
-               if (c_swapout_count == 0)
-                       vm_swap_consider_defragmenting();
+       vm_pageout_io_throttle();
 
-               lck_mtx_lock_spin_always(c_list_lock);
+       lck_mtx_lock_spin_always(c_list_lock);
+
+       /*
+        * Recheck if we have some c_segs to wakeup
+        * post throttle. And, check to see if we
+        * have any more swapouts needed.
+        */
+       if (vm_swapout_soc_done) {
+               goto again;
        }
 
        assert_wait((event_t)&c_swapout_list_head, THREAD_UNINT);
 
+       vm_swapout_thread_running = FALSE;
+
        lck_mtx_unlock_always(c_list_lock);
 
        thread_block((thread_continue_t)vm_swapout_thread);
-       
+
        /* NOTREACHED */
 }
 
+
+void
+vm_swapout_iodone(void *io_context, int error)
+{
+       struct swapout_io_completion *soc;
+
+       soc = (struct swapout_io_completion *)io_context;
+
+       lck_mtx_lock_spin_always(c_list_lock);
+
+       soc->swp_io_done = 1;
+       soc->swp_io_error = error;
+       vm_swapout_soc_done++;
+
+       if (!vm_swapout_thread_running) {
+               thread_wakeup((event_t)&c_swapout_list_head);
+       }
+
+       lck_mtx_unlock_always(c_list_lock);
+}
+
+
+static void
+vm_swapout_finish(c_segment_t c_seg, uint64_t f_offset, uint32_t size, kern_return_t kr)
+{
+       PAGE_REPLACEMENT_DISALLOWED(TRUE);
+
+       if (kr == KERN_SUCCESS) {
+               kernel_memory_depopulate(compressor_map, (vm_offset_t)c_seg->c_store.c_buffer, size,
+                   KMA_COMPRESSOR, VM_KERN_MEMORY_COMPRESSOR);
+       }
+#if ENCRYPTED_SWAP
+       else {
+               vm_swap_decrypt(c_seg);
+       }
+#endif /* ENCRYPTED_SWAP */
+       lck_mtx_lock_spin_always(c_list_lock);
+       lck_mtx_lock_spin_always(&c_seg->c_lock);
+
+       if (kr == KERN_SUCCESS) {
+               int             new_state = C_ON_SWAPPEDOUT_Q;
+               boolean_t       insert_head = FALSE;
+
+               if (hibernate_flushing == TRUE) {
+                       if (c_seg->c_generation_id >= first_c_segment_to_warm_generation_id &&
+                           c_seg->c_generation_id <= last_c_segment_to_warm_generation_id) {
+                               insert_head = TRUE;
+                       }
+               } else if (C_SEG_ONDISK_IS_SPARSE(c_seg)) {
+                       new_state = C_ON_SWAPPEDOUTSPARSE_Q;
+               }
+
+               c_seg_switch_state(c_seg, new_state, insert_head);
+
+               c_seg->c_store.c_swap_handle = f_offset;
+
+               counter_add(&vm_statistics_swapouts, size >> PAGE_SHIFT);
+
+               if (c_seg->c_bytes_used) {
+                       OSAddAtomic64(-c_seg->c_bytes_used, &compressor_bytes_used);
+               }
+
+#if CONFIG_FREEZE
+               /*
+                * Successful swapout. Decrement the in-core compressed pages count.
+                */
+               OSAddAtomic(-(c_seg->c_slots_used), &c_segment_pages_compressed_incore);
+               assertf(c_segment_pages_compressed_incore >= 0, "-ve incore count %p 0x%x", c_seg, c_segment_pages_compressed_incore);
+#endif /* CONFIG_FREEZE */
+       } else {
+               if (c_seg->c_overage_swap == TRUE) {
+                       c_seg->c_overage_swap = FALSE;
+                       c_overage_swapped_count--;
+               }
+
+#if CONFIG_FREEZE
+               if (c_seg->c_task_owner) {
+                       c_seg_update_task_owner(c_seg, NULL);
+               }
+#endif /* CONFIG_FREEZE */
+
+               c_seg_switch_state(c_seg, C_ON_AGE_Q, FALSE);
+
+               if (!c_seg->c_on_minorcompact_q && C_SEG_UNUSED_BYTES(c_seg) >= PAGE_SIZE) {
+                       c_seg_need_delayed_compaction(c_seg, TRUE);
+               }
+       }
+       assert(c_seg->c_busy_swapping);
+       assert(c_seg->c_busy);
+
+       c_seg->c_busy_swapping = 0;
+       lck_mtx_unlock_always(c_list_lock);
+
+       C_SEG_WAKEUP_DONE(c_seg);
+       lck_mtx_unlock_always(&c_seg->c_lock);
+
+       PAGE_REPLACEMENT_DISALLOWED(FALSE);
+}
+
+
 boolean_t
 vm_swap_create_file()
 {
-       uint64_t        size = 0;
-       int             namelen = 0;
-       boolean_t       swap_file_created = FALSE;
-       boolean_t       swap_file_reuse = FALSE;
-       boolean_t       swap_file_pin = FALSE;
+       uint64_t        size = 0;
+       int             namelen = 0;
+       boolean_t       swap_file_created = FALSE;
+       boolean_t       swap_file_reuse = FALSE;
+       boolean_t       swap_file_pin = FALSE;
        struct swapfile *swf = NULL;
 
        /*
@@ -1043,9 +1336,9 @@ vm_swap_create_file()
        vm_compaction_swapper_do_init();
 
        /*
-        * Any swapfile structure ready for re-use?
-        */      
-       
+        * Any swapfile structure ready for re-use?
+        */
+
        lck_mtx_lock(&vm_swap_data_lock);
 
        swf = (struct swapfile*) queue_first(&swf_global_queue);
@@ -1054,24 +1347,20 @@ vm_swap_create_file()
                if (swf->swp_flags == SWAP_REUSE) {
                        swap_file_reuse = TRUE;
                        break;
-               }                       
+               }
                swf = (struct swapfile*) queue_next(&swf->swp_queue);
        }
 
        lck_mtx_unlock(&vm_swap_data_lock);
 
        if (swap_file_reuse == FALSE) {
-
                namelen = (int)strlen(swapfilename) + SWAPFILENAME_INDEX_LEN + 1;
-                       
-               swf = (struct swapfile*) kalloc(sizeof *swf);
-               memset(swf, 0, sizeof(*swf));
 
+               swf = kalloc_flags(sizeof *swf, Z_WAITOK | Z_ZERO);
                swf->swp_index = vm_num_swap_files + 1;
                swf->swp_pathlen = namelen;
-               swf->swp_path = (char*)kalloc(swf->swp_pathlen);
-
-               memset(swf->swp_path, 0, namelen);
+               swf->swp_path = kheap_alloc(KHEAP_DATA_BUFFERS, swf->swp_pathlen,
+                   Z_WAITOK | Z_ZERO);
 
                snprintf(swf->swp_path, namelen, "%s%d", swapfilename, vm_num_swap_files);
        }
@@ -1080,7 +1369,7 @@ vm_swap_create_file()
 
        if (swf->swp_vp == NULL) {
                if (swap_file_reuse == FALSE) {
-                       kfree(swf->swp_path, swf->swp_pathlen); 
+                       kheap_free(KHEAP_DATA_BUFFERS, swf->swp_path, swf->swp_pathlen);
                        kfree(swf, sizeof *swf);
                }
                return FALSE;
@@ -1090,11 +1379,9 @@ vm_swap_create_file()
        size = MAX_SWAP_FILE_SIZE;
 
        while (size >= MIN_SWAP_FILE_SIZE) {
-
                swap_file_pin = VM_SWAP_SHOULD_PIN(size);
 
                if (vm_swapfile_preallocate(swf->swp_vp, &size, &swap_file_pin) == 0) {
-
                        int num_bytes_for_bitmap = 0;
 
                        swap_file_created = TRUE;
@@ -1104,24 +1391,25 @@ vm_swap_create_file()
                        swf->swp_nseginuse = 0;
                        swf->swp_free_hint = 0;
 
-                       num_bytes_for_bitmap = MAX((swf->swp_nsegs >> 3) , 1);
+                       num_bytes_for_bitmap = MAX((swf->swp_nsegs >> 3), 1);
                        /*
                         * Allocate a bitmap that describes the
                         * number of segments held by this swapfile.
                         */
-                       swf->swp_bitmap = (uint8_t*)kalloc(num_bytes_for_bitmap);
-                       memset(swf->swp_bitmap, 0, num_bytes_for_bitmap);
+                       swf->swp_bitmap = kheap_alloc(KHEAP_DATA_BUFFERS,
+                           num_bytes_for_bitmap, Z_WAITOK | Z_ZERO);
 
-                       swf->swp_csegs = (c_segment_t *) kalloc(swf->swp_nsegs * sizeof(c_segment_t));
-                       memset(swf->swp_csegs, 0, (swf->swp_nsegs * sizeof(c_segment_t)));
+                       swf->swp_csegs = kalloc_flags(swf->swp_nsegs * sizeof(c_segment_t),
+                           Z_WAITOK | Z_ZERO);
 
                        /*
                         * passing a NULL trim_list into vnode_trim_list
                         * will return ENOTSUP if trim isn't supported
                         * and 0 if it is
                         */
-                       if (vnode_trim_list(swf->swp_vp, NULL, FALSE) == 0)
+                       if (vnode_trim_list(swf->swp_vp, NULL, FALSE) == 0) {
                                swp_trim_supported = TRUE;
+                       }
 
                        lck_mtx_lock(&vm_swap_data_lock);
 
@@ -1130,7 +1418,7 @@ vm_swap_create_file()
                        if (swap_file_reuse == FALSE) {
                                queue_enter(&swf_global_queue, swf, struct swapfile*, swp_queue);
                        }
-                       
+
                        vm_num_swap_files++;
 
                        vm_swapfile_total_segs_alloced += swf->swp_nsegs;
@@ -1144,42 +1432,40 @@ vm_swap_create_file()
                        lck_mtx_unlock(&vm_swap_data_lock);
 
                        thread_wakeup((event_t) &vm_num_swap_files);
-#if CONFIG_EMBEDDED
+#if !XNU_TARGET_OS_OSX
                        if (vm_num_swap_files == 1) {
-
                                c_overage_swapped_limit = (uint32_t)size / C_SEG_BUFSIZE;
 
-                               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE)
+                               if (VM_CONFIG_FREEZER_SWAP_IS_ACTIVE) {
                                        c_overage_swapped_limit /= 2;
+                               }
                        }
-#endif
+#endif /* !XNU_TARGET_OS_OSX */
                        break;
                } else {
-
                        size = size / 2;
                }
        }
        if (swap_file_created == FALSE) {
-
                vm_swapfile_close((uint64_t)(swf->swp_path), swf->swp_vp);
 
                swf->swp_vp = NULL;
 
                if (swap_file_reuse == FALSE) {
-                       kfree(swf->swp_path, swf->swp_pathlen); 
+                       kheap_free(KHEAP_DATA_BUFFERS, swf->swp_path, swf->swp_pathlen);
                        kfree(swf, sizeof *swf);
                }
        }
        return swap_file_created;
 }
 
-
+extern void vnode_put(struct vnode* vp);
 kern_return_t
 vm_swap_get(c_segment_t c_seg, uint64_t f_offset, uint64_t size)
 {
        struct swapfile *swf = NULL;
-       uint64_t        file_offset = 0;
-       int             retval = 0;
+       uint64_t        file_offset = 0;
+       int             retval = 0;
 
        assert(c_seg->c_store.c_buffer);
 
@@ -1187,7 +1473,8 @@ vm_swap_get(c_segment_t c_seg, uint64_t f_offset, uint64_t size)
 
        swf = vm_swapfile_for_handle(f_offset);
 
-       if (swf == NULL || ( !(swf->swp_flags & SWAP_READY) && !(swf->swp_flags & SWAP_RECLAIM))) {
+       if (swf == NULL || (!(swf->swp_flags & SWAP_READY) && !(swf->swp_flags & SWAP_RECLAIM))) {
+               vm_swap_get_failures++;
                retval = 1;
                goto done;
        }
@@ -1199,15 +1486,22 @@ vm_swap_get(c_segment_t c_seg, uint64_t f_offset, uint64_t size)
        C_SEG_MAKE_WRITEABLE(c_seg);
 #endif
        file_offset = (f_offset & SWAP_SLOT_MASK);
-       retval = vm_swapfile_io(swf->swp_vp, file_offset, (uint64_t)c_seg->c_store.c_buffer, (int)(size / PAGE_SIZE_64), SWAP_READ);
+
+       if ((retval = vnode_getwithref(swf->swp_vp)) != 0) {
+               printf("vm_swap_get: vnode_getwithref on swapfile failed with %d\n", retval);
+       } else {
+               retval = vm_swapfile_io(swf->swp_vp, file_offset, (uint64_t)c_seg->c_store.c_buffer, (int)(size / PAGE_SIZE_64), SWAP_READ, NULL);
+               vnode_put(swf->swp_vp);
+       }
 
 #if DEVELOPMENT || DEBUG
        C_SEG_WRITE_PROTECT(c_seg);
 #endif
-       if (retval == 0)
-               VM_STAT_INCR_BY(swapins, size >> PAGE_SHIFT);
-       else
+       if (retval == 0) {
+               counter_add(&vm_statistics_swapins, size >> PAGE_SHIFT);
+       } else {
                vm_swap_get_failures++;
+       }
 
        /*
         * Free this slot in the swap structure.
@@ -1218,36 +1512,38 @@ vm_swap_get(c_segment_t c_seg, uint64_t f_offset, uint64_t size)
        swf->swp_io_count--;
 
        if ((swf->swp_flags & SWAP_WANTED) && swf->swp_io_count == 0) {
-       
                swf->swp_flags &= ~SWAP_WANTED;
                thread_wakeup((event_t) &swf->swp_flags);
        }
 done:
        lck_mtx_unlock(&vm_swap_data_lock);
 
-       if (retval == 0)
+       if (retval == 0) {
                return KERN_SUCCESS;
-       else
+       } else {
                return KERN_FAILURE;
+       }
 }
 
 kern_return_t
-vm_swap_put(vm_offset_t addr, uint64_t *f_offset, uint64_t size, c_segment_t c_seg)
+vm_swap_put(vm_offset_t addr, uint64_t *f_offset, uint32_t size, c_segment_t c_seg, struct swapout_io_completion *soc)
 {
-       unsigned int    segidx = 0;
+       unsigned int    segidx = 0;
        struct swapfile *swf = NULL;
-       uint64_t        file_offset = 0;
-       uint64_t        swapfile_index = 0;
-       unsigned int    byte_for_segidx = 0;
-       unsigned int    offset_within_byte = 0;
-       boolean_t       swf_eligible = FALSE;
-       boolean_t       waiting = FALSE;
-       boolean_t       retried = FALSE;
-       int             error = 0;
-       clock_sec_t     sec;
-       clock_nsec_t    nsec;
-
-       if (addr == 0 || f_offset == NULL) {
+       uint64_t        file_offset = 0;
+       uint64_t        swapfile_index = 0;
+       unsigned int    byte_for_segidx = 0;
+       unsigned int    offset_within_byte = 0;
+       boolean_t       swf_eligible = FALSE;
+       boolean_t       waiting = FALSE;
+       boolean_t       retried = FALSE;
+       int             error = 0;
+       clock_sec_t     sec;
+       clock_nsec_t    nsec;
+       void            *upl_ctx = NULL;
+       boolean_t       drop_iocount = FALSE;
+
+       if (addr == 0 || f_offset == NULL || compressor_store_stop_compaction) {
                return KERN_FAILURE;
        }
 retry:
@@ -1255,47 +1551,46 @@ retry:
 
        swf = (struct swapfile*) queue_first(&swf_global_queue);
 
-       while(queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
-       
+       while (queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
                segidx = swf->swp_free_hint;
 
-               swf_eligible =  (swf->swp_flags & SWAP_READY) && (swf->swp_nseginuse < swf->swp_nsegs);
+               swf_eligible =  (swf->swp_flags & SWAP_READY) && (swf->swp_nseginuse < swf->swp_nsegs);
 
                if (swf_eligible) {
-
-                       while(segidx < swf->swp_nsegs) {
-                               
+                       while (segidx < swf->swp_nsegs) {
                                byte_for_segidx = segidx >> 3;
                                offset_within_byte = segidx % 8;
-                       
+
                                if ((swf->swp_bitmap)[byte_for_segidx] & (1 << offset_within_byte)) {
                                        segidx++;
                                        continue;
                                }
-               
+
                                (swf->swp_bitmap)[byte_for_segidx] |= (1 << offset_within_byte);
 
                                file_offset = segidx * COMPRESSED_SWAP_CHUNK_SIZE;
                                swf->swp_nseginuse++;
                                swf->swp_io_count++;
-                               swapfile_index = swf->swp_index;
+                               swf->swp_csegs[segidx] = c_seg;
 
+                               swapfile_index = swf->swp_index;
                                vm_swapfile_total_segs_used++;
 
                                clock_get_system_nanotime(&sec, &nsec);
 
-                               if (VM_SWAP_SHOULD_CREATE(sec) && !vm_swapfile_create_thread_running)
+                               if (VM_SWAP_SHOULD_CREATE(sec) && !vm_swapfile_create_thread_running) {
                                        thread_wakeup((event_t) &vm_swapfile_create_needed);
+                               }
 
                                lck_mtx_unlock(&vm_swap_data_lock);
-               
-                               goto done;
+
+                               goto issue_io;
                        }
                }
                swf = (struct swapfile*) queue_next(&swf->swp_queue);
        }
        assert(queue_end(&swf_global_queue, (queue_entry_t) swf));
-       
+
        /*
         * we've run out of swap segments, but may not
         * be in a position to immediately create a new swap
@@ -1313,14 +1608,16 @@ retry:
         */
        clock_get_system_nanotime(&sec, &nsec);
 
-       if (VM_SWAP_SHOULD_CREATE(sec) && !vm_swapfile_create_thread_running)
+       if (VM_SWAP_SHOULD_CREATE(sec) && !vm_swapfile_create_thread_running) {
                thread_wakeup((event_t) &vm_swapfile_create_needed);
+       }
 
        if (hibernate_flushing == FALSE || VM_SWAP_SHOULD_CREATE(sec)) {
                waiting = TRUE;
-               assert_wait_timeout((event_t) &vm_num_swap_files, THREAD_INTERRUPTIBLE, 1000, 1000*NSEC_PER_USEC);
-       } else
+               assert_wait_timeout((event_t) &vm_num_swap_files, THREAD_INTERRUPTIBLE, 1000, 1000 * NSEC_PER_USEC);
+       } else {
                hibernate_no_swapspace = TRUE;
+       }
 
        lck_mtx_unlock(&vm_swap_data_lock);
 
@@ -1332,32 +1629,62 @@ retry:
                        goto retry;
                }
        }
-       vm_swap_put_failures++;
+       vm_swap_put_failures_no_swap_file++;
 
        return KERN_FAILURE;
 
-done:  
-       error = vm_swapfile_io(swf->swp_vp, file_offset, addr, (int) (size / PAGE_SIZE_64), SWAP_WRITE);
+issue_io:
+       assert(c_seg->c_busy_swapping);
+       assert(c_seg->c_busy);
+       assert(!c_seg->c_on_minorcompact_q);
 
-       lck_mtx_lock(&vm_swap_data_lock);
+       *f_offset = (swapfile_index << SWAP_DEVICE_SHIFT) | file_offset;
 
-       swf->swp_csegs[segidx] = c_seg;
+       if (soc) {
+               soc->swp_c_seg = c_seg;
+               soc->swp_c_size = size;
 
-       swf->swp_io_count--;
+               soc->swp_swf = swf;
 
-       *f_offset = (swapfile_index << SWAP_DEVICE_SHIFT) | file_offset;
+               soc->swp_io_error = 0;
+               soc->swp_io_done = 0;
+
+               upl_ctx = (void *)&soc->swp_upl_ctx;
+       }
+
+       if ((error = vnode_getwithref(swf->swp_vp)) != 0) {
+               printf("vm_swap_put: vnode_getwithref on swapfile failed with %d\n", error);
+       } else {
+               error = vm_swapfile_io(swf->swp_vp, file_offset, addr, (int) (size / PAGE_SIZE_64), SWAP_WRITE, upl_ctx);
+               drop_iocount = TRUE;
+       }
+
+       if (error || upl_ctx == NULL) {
+               return vm_swap_put_finish(swf, f_offset, error, drop_iocount);
+       }
+
+       return KERN_SUCCESS;
+}
+
+kern_return_t
+vm_swap_put_finish(struct swapfile *swf, uint64_t *f_offset, int error, boolean_t drop_iocount)
+{
+       if (drop_iocount) {
+               vnode_put(swf->swp_vp);
+       }
+
+       lck_mtx_lock(&vm_swap_data_lock);
+
+       swf->swp_io_count--;
 
        if ((swf->swp_flags & SWAP_WANTED) && swf->swp_io_count == 0) {
-       
                swf->swp_flags &= ~SWAP_WANTED;
                thread_wakeup((event_t) &swf->swp_flags);
        }
-
        lck_mtx_unlock(&vm_swap_data_lock);
 
        if (error) {
                vm_swap_free(*f_offset);
-
                vm_swap_put_failures++;
 
                return KERN_FAILURE;
@@ -1366,27 +1693,24 @@ done:
 }
 
 
-
 static void
 vm_swap_free_now(struct swapfile *swf, uint64_t f_offset)
 {
-       uint64_t        file_offset = 0;
-       unsigned int    segidx = 0;
+       uint64_t        file_offset = 0;
+       unsigned int    segidx = 0;
 
 
        if ((swf->swp_flags & SWAP_READY) || (swf->swp_flags & SWAP_RECLAIM)) {
-
                unsigned int byte_for_segidx = 0;
                unsigned int offset_within_byte = 0;
 
                file_offset = (f_offset & SWAP_SLOT_MASK);
                segidx = (unsigned int) (file_offset / COMPRESSED_SWAP_CHUNK_SIZE);
-                       
+
                byte_for_segidx = segidx >> 3;
                offset_within_byte = segidx % 8;
 
                if ((swf->swp_bitmap)[byte_for_segidx] & (1 << offset_within_byte)) {
-                               
                        (swf->swp_bitmap)[byte_for_segidx] &= ~(1 << offset_within_byte);
 
                        swf->swp_csegs[segidx] = NULL;
@@ -1398,8 +1722,9 @@ vm_swap_free_now(struct swapfile *swf, uint64_t f_offset)
                                swf->swp_free_hint = segidx;
                        }
                }
-               if (VM_SWAP_SHOULD_RECLAIM() && !vm_swapfile_gc_thread_running)
+               if (VM_SWAP_SHOULD_RECLAIM() && !vm_swapfile_gc_thread_running) {
                        thread_wakeup((event_t) &vm_swapfile_gc_needed);
+               }
        }
 }
 
@@ -1413,18 +1738,18 @@ vm_swap_free(uint64_t f_offset)
 {
        struct swapfile *swf = NULL;
        struct trim_list *tl = NULL;
-        clock_sec_t     sec;
-        clock_nsec_t    nsec;
+       clock_sec_t     sec;
+       clock_nsec_t    nsec;
 
-       if (swp_trim_supported == TRUE)
+       if (swp_trim_supported == TRUE) {
                tl = kalloc(sizeof(struct trim_list));
+       }
 
        lck_mtx_lock(&vm_swap_data_lock);
 
        swf = vm_swapfile_for_handle(f_offset);
 
        if (swf && (swf->swp_flags & (SWAP_READY | SWAP_RECLAIM))) {
-
                if (swp_trim_supported == FALSE || (swf->swp_flags & SWAP_RECLAIM)) {
                        /*
                         * don't delay the free if the underlying disk doesn't support
@@ -1448,29 +1773,30 @@ vm_swap_free(uint64_t f_offset)
                if (VM_SWAP_SHOULD_TRIM(swf) && !vm_swapfile_create_thread_running) {
                        clock_get_system_nanotime(&sec, &nsec);
 
-                       if (sec > dont_trim_until_ts)
+                       if (sec > dont_trim_until_ts) {
                                thread_wakeup((event_t) &vm_swapfile_create_needed);
+                       }
                }
                vm_swap_free_delayed_count++;
        }
 done:
        lck_mtx_unlock(&vm_swap_data_lock);
 
-       if (tl != NULL)
+       if (tl != NULL) {
                kfree(tl, sizeof(struct trim_list));
-}      
+       }
+}
 
 
 static void
 vm_swap_wait_on_trim_handling_in_progress()
 {
        while (delayed_trim_handling_in_progress == TRUE) {
-
                assert_wait((event_t) &delayed_trim_handling_in_progress, THREAD_UNINT);
                lck_mtx_unlock(&vm_swap_data_lock);
-               
+
                thread_block(THREAD_CONTINUE_NULL);
-               
+
                lck_mtx_lock(&vm_swap_data_lock);
        }
 }
@@ -1488,6 +1814,11 @@ vm_swap_handle_delayed_trims(boolean_t force_now)
         * that file since vm_swap_reclaim will first process
         * all of the delayed trims associated with it
         */
+
+       if (compressor_store_stop_compaction == TRUE) {
+               return;
+       }
+
        lck_mtx_lock(&vm_swap_data_lock);
 
        delayed_trim_handling_in_progress = TRUE;
@@ -1504,9 +1835,7 @@ vm_swap_handle_delayed_trims(boolean_t force_now)
        swf = (struct swapfile*) queue_first(&swf_global_queue);
 
        while (queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
-
                if ((swf->swp_flags & SWAP_READY) && (force_now == TRUE || VM_SWAP_SHOULD_TRIM(swf))) {
-
                        assert(!(swf->swp_flags & SWAP_RECLAIM));
                        vm_swap_do_delayed_trim(swf);
                }
@@ -1517,17 +1846,27 @@ vm_swap_handle_delayed_trims(boolean_t force_now)
        delayed_trim_handling_in_progress = FALSE;
        thread_wakeup((event_t) &delayed_trim_handling_in_progress);
 
-       if (VM_SWAP_SHOULD_RECLAIM() && !vm_swapfile_gc_thread_running)
+       if (VM_SWAP_SHOULD_RECLAIM() && !vm_swapfile_gc_thread_running) {
                thread_wakeup((event_t) &vm_swapfile_gc_needed);
+       }
 
        lck_mtx_unlock(&vm_swap_data_lock);
-
 }
 
 static void
 vm_swap_do_delayed_trim(struct swapfile *swf)
 {
        struct trim_list *tl, *tl_head;
+       int error;
+
+       if (compressor_store_stop_compaction == TRUE) {
+               return;
+       }
+
+       if ((error = vnode_getwithref(swf->swp_vp)) != 0) {
+               printf("vm_swap_do_delayed_trim: vnode_getwithref on swapfile failed with %d\n", error);
+               return;
+       }
 
        lck_mtx_lock(&vm_swap_data_lock);
 
@@ -1538,23 +1877,24 @@ vm_swap_do_delayed_trim(struct swapfile *swf)
        lck_mtx_unlock(&vm_swap_data_lock);
 
        vnode_trim_list(swf->swp_vp, tl_head, TRUE);
-       
+
+       (void) vnode_put(swf->swp_vp);
+
        while ((tl = tl_head) != NULL) {
-               unsigned int    segidx = 0;
-               unsigned int    byte_for_segidx = 0;
-               unsigned int    offset_within_byte = 0;
+               unsigned int    segidx = 0;
+               unsigned int    byte_for_segidx = 0;
+               unsigned int    offset_within_byte = 0;
 
                lck_mtx_lock(&vm_swap_data_lock);
 
                segidx = (unsigned int) (tl->tl_offset / COMPRESSED_SWAP_CHUNK_SIZE);
-                       
+
                byte_for_segidx = segidx >> 3;
                offset_within_byte = segidx % 8;
 
                if ((swf->swp_bitmap)[byte_for_segidx] & (1 << offset_within_byte)) {
-                               
                        (swf->swp_bitmap)[byte_for_segidx] &= ~(1 << offset_within_byte);
-                       
+
                        swf->swp_csegs[segidx] = NULL;
 
                        swf->swp_nseginuse--;
@@ -1569,7 +1909,7 @@ vm_swap_do_delayed_trim(struct swapfile *swf)
                tl_head = tl->tl_next;
 
                kfree(tl, sizeof(struct trim_list));
-       }               
+       }
 }
 
 
@@ -1579,23 +1919,23 @@ vm_swap_flush()
        return;
 }
 
-int    vm_swap_reclaim_yielded = 0;
+int     vm_swap_reclaim_yielded = 0;
 
 void
 vm_swap_reclaim(void)
 {
-       vm_offset_t     addr = 0;
-       unsigned int    segidx = 0;
-       uint64_t        f_offset = 0;
+       vm_offset_t     addr = 0;
+       unsigned int    segidx = 0;
+       uint64_t        f_offset = 0;
        struct swapfile *swf = NULL;
        struct swapfile *smallest_swf = NULL;
-       unsigned int    min_nsegs = 0;  
-       unsigned int    byte_for_segidx = 0;
-       unsigned int    offset_within_byte = 0;
-       uint32_t        c_size = 0;
+       unsigned int    min_nsegs = 0;
+       unsigned int    byte_for_segidx = 0;
+       unsigned int    offset_within_byte = 0;
+       uint32_t        c_size = 0;
+
+       c_segment_t     c_seg = NULL;
 
-       c_segment_t     c_seg = NULL;
-       
        if (kernel_memory_allocate(compressor_map, (vm_offset_t *)(&addr), C_SEG_BUFSIZE, 0, KMA_KOBJECT, VM_KERN_MEMORY_COMPRESSOR) != KERN_SUCCESS) {
                panic("vm_swap_reclaim: kernel_memory_allocate failed\n");
        }
@@ -1621,17 +1961,16 @@ vm_swap_reclaim(void)
        smallest_swf = NULL;
 
        while (queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
-
                if ((swf->swp_flags & SWAP_READY) && (swf->swp_nseginuse <= min_nsegs)) {
-
                        smallest_swf = swf;
                        min_nsegs = swf->swp_nseginuse;
-               }                       
+               }
                swf = (struct swapfile*) queue_next(&swf->swp_queue);
        }
-       
-       if (smallest_swf == NULL)
+
+       if (smallest_swf == NULL) {
                goto done;
+       }
 
        swf = smallest_swf;
 
@@ -1640,7 +1979,6 @@ vm_swap_reclaim(void)
        swf->swp_flags |= SWAP_RECLAIM;
 
        if (swf->swp_delayed_trim_count) {
-
                lck_mtx_unlock(&vm_swap_data_lock);
 
                vm_swap_do_delayed_trim(swf);
@@ -1650,23 +1988,21 @@ vm_swap_reclaim(void)
        segidx = 0;
 
        while (segidx < swf->swp_nsegs) {
-
-ReTry_for_cseg:        
+ReTry_for_cseg:
                /*
                 * Wait for outgoing I/Os.
                 */
                while (swf->swp_io_count) {
-
                        swf->swp_flags |= SWAP_WANTED;
 
                        assert_wait((event_t) &swf->swp_flags, THREAD_UNINT);
                        lck_mtx_unlock(&vm_swap_data_lock);
-               
+
                        thread_block(THREAD_CONTINUE_NULL);
-               
+
                        lck_mtx_lock(&vm_swap_data_lock);
                }
-               if (compressor_store_stop_compaction == TRUE || VM_SWAP_SHOULD_ABORT_RECLAIM() || VM_SWAP_BUSY()) {
+               if (compressor_store_stop_compaction == TRUE || VM_SWAP_SHOULD_ABORT_RECLAIM() || VM_SWAP_BUSY()) {
                        vm_swap_reclaim_yielded++;
                        break;
                }
@@ -1675,7 +2011,6 @@ ReTry_for_cseg:
                offset_within_byte = segidx % 8;
 
                if (((swf->swp_bitmap)[byte_for_segidx] & (1 << offset_within_byte)) == 0) {
-
                        segidx++;
                        continue;
                }
@@ -1696,16 +2031,16 @@ ReTry_for_cseg:
                         * this c_segment no longer exists.
                         */
                        c_seg->c_wanted = 1;
-                       
+
                        assert_wait((event_t) (c_seg), THREAD_UNINT);
                        lck_mtx_unlock_always(&c_seg->c_lock);
-                       
+
                        lck_mtx_unlock(&vm_swap_data_lock);
-                       
+
                        thread_block(THREAD_CONTINUE_NULL);
 
                        lck_mtx_lock(&vm_swap_data_lock);
-                       
+
                        goto ReTry_for_cseg;
                }
                (swf->swp_bitmap)[byte_for_segidx] &= ~(1 << offset_within_byte);
@@ -1717,10 +2052,10 @@ ReTry_for_cseg:
                swf->swp_nseginuse--;
 
                vm_swapfile_total_segs_used--;
-                       
+
                lck_mtx_unlock(&vm_swap_data_lock);
 
-               assert(C_SEG_IS_ONDISK(c_seg)); 
+               assert(C_SEG_IS_ONDISK(c_seg));
 
                C_SEG_BUSY(c_seg);
                c_seg->c_busy_swapping = 1;
@@ -1728,29 +2063,36 @@ ReTry_for_cseg:
                c_seg_trim_tail(c_seg);
 #endif
                c_size = round_page_32(C_SEG_OFFSET_TO_BYTES(c_seg->c_populated_offset));
-               
+
                assert(c_size <= C_SEG_BUFSIZE && c_size);
 
                lck_mtx_unlock_always(&c_seg->c_lock);
 
-               if (vm_swapfile_io(swf->swp_vp, f_offset, addr, (int)(c_size / PAGE_SIZE_64), SWAP_READ)) {
-
-                       /*
-                        * reading the data back in failed, so convert c_seg
-                        * to a swapped in c_segment that contains no data
-                        */
-                       c_seg_swapin_requeue(c_seg, FALSE, TRUE, FALSE);
-                       /*
-                        * returns with c_busy_swapping cleared
-                        */
-
+               if (vnode_getwithref(swf->swp_vp)) {
+                       printf("vm_swap_reclaim: vnode_getwithref on swapfile failed.\n");
                        vm_swap_get_failures++;
                        goto swap_io_failed;
+               } else {
+                       if (vm_swapfile_io(swf->swp_vp, f_offset, addr, (int)(c_size / PAGE_SIZE_64), SWAP_READ, NULL)) {
+                               /*
+                                * reading the data back in failed, so convert c_seg
+                                * to a swapped in c_segment that contains no data
+                                */
+                               c_seg_swapin_requeue(c_seg, FALSE, TRUE, FALSE);
+                               /*
+                                * returns with c_busy_swapping cleared
+                                */
+                               vnode_put(swf->swp_vp);
+                               vm_swap_get_failures++;
+                               goto swap_io_failed;
+                       }
+                       vnode_put(swf->swp_vp);
                }
-               VM_STAT_INCR_BY(swapins, c_size >> PAGE_SHIFT);
 
-               if (vm_swap_put(addr, &f_offset, c_size, c_seg)) {
-                       vm_offset_t     c_buffer;
+               counter_add(&vm_statistics_swapins, c_size >> PAGE_SHIFT);
+
+               if (vm_swap_put(addr, &f_offset, c_size, c_seg, NULL)) {
+                       vm_offset_t     c_buffer;
 
                        /*
                         * the put failed, so convert c_seg to a fully swapped in c_segment
@@ -1774,10 +2116,10 @@ ReTry_for_cseg:
 
                        goto swap_io_failed;
                }
-               VM_STAT_INCR_BY(swapouts, c_size >> PAGE_SHIFT);
+               counter_add(&vm_statistics_swapouts, c_size >> PAGE_SHIFT);
 
                lck_mtx_lock_spin_always(&c_seg->c_lock);
-                               
+
                assert(C_SEG_IS_ONDISK(c_seg));
                /*
                 * The c_seg will now know about the new location on disk.
@@ -1789,28 +2131,25 @@ ReTry_for_cseg:
 swap_io_failed:
                assert(c_seg->c_busy);
                C_SEG_WAKEUP_DONE(c_seg);
-                               
+
                lck_mtx_unlock_always(&c_seg->c_lock);
                lck_mtx_lock(&vm_swap_data_lock);
        }
 
        if (swf->swp_nseginuse) {
-
                swf->swp_flags &= ~SWAP_RECLAIM;
                swf->swp_flags |= SWAP_READY;
 
                goto done;
        }
        /*
-        * We don't remove this inactive swf from the queue.
+        * We don't remove this inactive swf from the queue.
         * That way, we can re-use it when needed again and
         * preserve the namespace. The delayed_trim processing
         * is also dependent on us not removing swfs from the queue.
-        */      
+        */
        //queue_remove(&swf_global_queue, swf, struct swapfile*, swp_queue);
 
-       vm_num_swap_files--;
-
        vm_swapfile_total_segs_alloced -= swf->swp_nsegs;
 
        lck_mtx_unlock(&vm_swap_data_lock);
@@ -1818,8 +2157,9 @@ swap_io_failed:
        vm_swapfile_close((uint64_t)(swf->swp_path), swf->swp_vp);
 
        kfree(swf->swp_csegs, swf->swp_nsegs * sizeof(c_segment_t));
-       kfree(swf->swp_bitmap, MAX((swf->swp_nsegs >> 3), 1));
-       
+       kheap_free(KHEAP_DATA_BUFFERS, swf->swp_bitmap,
+           MAX((swf->swp_nsegs >> 3), 1));
+
        lck_mtx_lock(&vm_swap_data_lock);
 
        if (swf->swp_flags & SWAP_PINNED) {
@@ -1827,12 +2167,14 @@ swap_io_failed:
                vm_swappin_avail += swf->swp_size;
        }
 
-       swf->swp_vp = NULL;     
+       swf->swp_vp = NULL;
        swf->swp_size = 0;
        swf->swp_free_hint = 0;
        swf->swp_nsegs = 0;
        swf->swp_flags = SWAP_REUSE;
 
+       vm_num_swap_files--;
+
 done:
        thread_wakeup((event_t) &swf->swp_flags);
        lck_mtx_unlock(&vm_swap_data_lock);
@@ -1864,37 +2206,113 @@ vm_swap_get_used_space(void)
 uint64_t
 vm_swap_get_free_space(void)
 {
-       return (vm_swap_get_total_space() - vm_swap_get_used_space());
+       return vm_swap_get_total_space() - vm_swap_get_used_space();
 }
 
+uint64_t
+vm_swap_get_max_configured_space(void)
+{
+       int num_swap_files = (vm_num_swap_files_config ? vm_num_swap_files_config : VM_MAX_SWAP_FILE_NUM);
+       return num_swap_files * MAX_SWAP_FILE_SIZE;
+}
 
 int
 vm_swap_low_on_space(void)
 {
-
-       if (vm_num_swap_files == 0 && vm_swapfile_can_be_created == FALSE)
-               return (0);
+       if (vm_num_swap_files == 0 && vm_swapfile_can_be_created == FALSE) {
+               return 0;
+       }
 
        if (((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < ((unsigned int)VM_SWAPFILE_HIWATER_SEGS) / 8)) {
+               if (vm_num_swap_files == 0 && !SWAPPER_NEEDS_TO_UNTHROTTLE()) {
+                       return 0;
+               }
 
-               if (vm_num_swap_files == 0 && !SWAPPER_NEEDS_TO_UNTHROTTLE())
-                       return (0);
+               if (vm_swapfile_last_failed_to_create_ts >= vm_swapfile_last_successful_create_ts) {
+                       return 1;
+               }
+       }
+       return 0;
+}
 
-               if (vm_swapfile_last_failed_to_create_ts >= vm_swapfile_last_successful_create_ts)
-                       return (1);
+int
+vm_swap_out_of_space(void)
+{
+       if ((vm_num_swap_files == vm_num_swap_files_config) &&
+           ((vm_swapfile_total_segs_alloced - vm_swapfile_total_segs_used) < VM_SWAPOUT_LIMIT_MAX)) {
+               /*
+                * Last swapfile and we have only space for the
+                * last few swapouts.
+                */
+               return 1;
        }
-       return (0);
+
+       return 0;
 }
 
 boolean_t
 vm_swap_files_pinned(void)
 {
-        boolean_t result;
+       boolean_t result;
+
+       if (vm_swappin_enabled == FALSE) {
+               return TRUE;
+       }
+
+       result = (vm_num_pinned_swap_files == vm_num_swap_files);
+
+       return result;
+}
+
+#if CONFIG_FREEZE
+boolean_t
+vm_swap_max_budget(uint64_t *freeze_daily_budget)
+{
+       boolean_t       use_device_value = FALSE;
+       struct swapfile *swf = NULL;
+
+       if (vm_num_swap_files) {
+               lck_mtx_lock(&vm_swap_data_lock);
+
+               swf = (struct swapfile*) queue_first(&swf_global_queue);
+
+               if (swf) {
+                       while (queue_end(&swf_global_queue, (queue_entry_t)swf) == FALSE) {
+                               if (swf->swp_flags == SWAP_READY) {
+                                       assert(swf->swp_vp);
 
-       if (vm_swappin_enabled == FALSE)
-               return(TRUE);
+                                       if (vm_swap_vol_get_budget(swf->swp_vp, freeze_daily_budget) == 0) {
+                                               use_device_value = TRUE;
+                                       }
+                                       break;
+                               }
+                               swf = (struct swapfile*) queue_next(&swf->swp_queue);
+                       }
+               }
+
+               lck_mtx_unlock(&vm_swap_data_lock);
+       } else {
+               /*
+                * This block is used for the initial budget value before any swap files
+                * are created. We create a temp swap file to get the budget.
+                */
 
-        result = (vm_num_pinned_swap_files == vm_num_swap_files);
+               struct vnode *temp_vp = NULL;
+
+               vm_swapfile_open(swapfilename, &temp_vp);
+
+               if (temp_vp) {
+                       if (vm_swap_vol_get_budget(temp_vp, freeze_daily_budget) == 0) {
+                               use_device_value = TRUE;
+                       }
+
+                       vm_swapfile_close((uint64_t)&swapfilename, temp_vp);
+                       temp_vp = NULL;
+               } else {
+                       *freeze_daily_budget = 0;
+               }
+       }
 
-        return (result);
+       return use_device_value;
 }
+#endif /* CONFIG_FREEZE */