osfmk/vm/vm_phantom_cache.h

   1 /*
   2  * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <vm/vm_page.h>
  30
  31 #define         VM_GHOST_OFFSET_BITS    39
  32 #define         VM_GHOST_OFFSET_MASK    0x7FFFFFFFFF
  33 #define         VM_GHOST_PAGES_PER_ENTRY 4
  34 #define         VM_GHOST_PAGE_MASK      0x3
  35 #define         VM_GHOST_PAGE_SHIFT     2
  36 #define         VM_GHOST_INDEX_BITS     (64 - VM_GHOST_OFFSET_BITS - VM_GHOST_PAGES_PER_ENTRY)
  37
  38 struct  vm_ghost {
  39         uint64_t        g_next_index:VM_GHOST_INDEX_BITS,
  40             g_pages_held:VM_GHOST_PAGES_PER_ENTRY,
  41             g_obj_offset:VM_GHOST_OFFSET_BITS;
  42         uint32_t        g_obj_id;
  43 } __attribute__((packed));
  44
  45 typedef struct vm_ghost *vm_ghost_t;
  46
  47
  48 extern  void            vm_phantom_cache_init(void);
  49 extern  void            vm_phantom_cache_add_ghost(vm_page_t);
  50 extern  vm_ghost_t      vm_phantom_cache_lookup_ghost(vm_page_t, uint32_t);
  51 extern  void            vm_phantom_cache_update(vm_page_t);
  52 extern  boolean_t       vm_phantom_cache_check_pressure(void);
  53 extern  void            vm_phantom_cache_restart_sample(void);