[1] | 1 | /* |
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| 2 | * page.h - physical page descriptor and related operations |
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| 3 | * |
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| 4 | * Authors Ghassan Almalles (2008,2009,2010,2011,2012) |
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| 5 | * Alain Greiner (2016) |
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| 6 | * |
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| 7 | * Copyright (c) UPMC Sorbonne Universites |
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| 8 | * |
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| 9 | * This file is part of ALMOS-MKH. |
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| 10 | * |
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| 11 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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| 12 | * under the terms of the GNU General Public License as published by |
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| 13 | * the Free Software Foundation; version 2.0 of the License. |
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| 14 | * |
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| 15 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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| 16 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 18 | * General Public License for more details. |
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| 19 | * |
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| 20 | * You should have received a copy of the GNU General Public License |
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| 21 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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| 22 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 23 | */ |
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| 24 | |
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| 25 | #ifndef _PAGE_H_ |
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| 26 | #define _PAGE_H_ |
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| 27 | |
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[14] | 28 | #include <kernel_config.h> |
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[1] | 29 | #include <hal_types.h> |
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| 30 | #include <spinlock.h> |
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| 31 | #include <list.h> |
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| 32 | #include <slist.h> |
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| 33 | #include <xlist.h> |
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| 34 | |
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| 35 | /*** Forward declarations ***/ |
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| 36 | |
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| 37 | struct mapper_s; |
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[18] | 38 | |
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[1] | 39 | /************************************************************************************* |
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| 40 | * This defines the flags that can be attached to a physical page. |
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| 41 | ************************************************************************************/ |
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| 42 | |
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| 43 | #define PG_INIT 0x0001 // page descriptor has been initialised |
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| 44 | #define PG_RESERVED 0x0002 // cannot be allocated by PPM |
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| 45 | #define PG_FREE 0x0004 // page can be allocated by PPM |
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[18] | 46 | #define PG_INLOAD 0x0008 // on-going load from disk |
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[1] | 47 | #define PG_IO_ERR 0x0010 // mapper signals a read/write access error |
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| 48 | #define PG_BUFFER 0x0020 // used in blockio.c |
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| 49 | #define PG_DIRTY 0x0040 // page has been written |
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| 50 | #define PG_LOCKED 0x0080 // page is locked |
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[23] | 51 | #define PG_COW 0x0100 // page is copy-on-write |
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[1] | 52 | |
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| 53 | #define PG_ALL 0xFFFF // All flags |
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| 54 | |
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| 55 | /************************************************************************************* |
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| 56 | * This structure defines a physical page descriptor. |
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[23] | 57 | * Size is 64 bytes for a 32 bits core... |
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[1] | 58 | ************************************************************************************/ |
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| 59 | |
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| 60 | typedef struct page_s |
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| 61 | { |
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[23] | 62 | uint32_t flags; /*! flags defined above (4) */ |
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[68] | 63 | uint32_t order; /*! log2( number of small pages) (4) */ |
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[1] | 64 | struct mapper_s * mapper; /*! local pointer on associated mapper (4) */ |
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| 65 | uint32_t index; /*! page index in mapper (4) */ |
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[18] | 66 | list_entry_t list; /*! for both dirty pages and free pages (8) */ |
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[1] | 67 | xlist_entry_t wait_root; /*! root of list of waiting threads (16) */ |
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| 68 | uint32_t refcount; /*! reference counter (4) */ |
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[23] | 69 | uint32_t fork_nr; /*! number of forked processes (4) */ |
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[1] | 70 | spinlock_t lock; /*! only used to set the PG_LOCKED flag (16) */ |
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| 71 | } |
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| 72 | page_t; |
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| 73 | |
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| 74 | /************************************************************************************* |
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| 75 | * This function initializes one page descriptor. |
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[23] | 76 | ************************************************************************************* |
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[1] | 77 | * @ page : pointer to page descriptor |
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| 78 | ************************************************************************************/ |
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| 79 | inline void page_init( page_t * page ); |
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| 80 | |
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| 81 | /************************************************************************************* |
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[23] | 82 | * This function atomically set one or several flags in page descriptor flags. |
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| 83 | ************************************************************************************* |
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[1] | 84 | * @ page : pointer to page descriptor. |
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[18] | 85 | * @ value : all non zero bits in value will be set. |
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[1] | 86 | ************************************************************************************/ |
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| 87 | inline void page_set_flag( page_t * page, |
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[23] | 88 | uint32_t value ); |
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[1] | 89 | |
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| 90 | /************************************************************************************* |
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[23] | 91 | * This function atomically reset one or several flags in page descriptor flags. |
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| 92 | ************************************************************************************* |
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[1] | 93 | * @ page : pointer to page descriptor. |
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[18] | 94 | * @ value : all non zero bits in value will be cleared. |
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[1] | 95 | ************************************************************************************/ |
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| 96 | inline void page_clear_flag( page_t * page, |
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[23] | 97 | uint32_t value ); |
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[1] | 98 | |
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| 99 | /************************************************************************************* |
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[22] | 100 | * This function tests the value of one or several flags in page descriptor flags. |
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[23] | 101 | ************************************************************************************* |
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[1] | 102 | * @ page : pointer to page descriptor. |
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| 103 | * @ value : all non zero bits will be tested. |
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[18] | 104 | * @ returns true if at least one non zero bit in value is set / false otherwise. |
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[1] | 105 | ************************************************************************************/ |
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| 106 | inline bool_t page_is_flag( page_t * page, |
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[23] | 107 | uint32_t value ); |
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[1] | 108 | |
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| 109 | /************************************************************************************* |
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| 110 | * This function synchronizes (i.e. update the disk) all dirty pages in a cluster. |
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[22] | 111 | * It scans the PPM dirty list, that should be empty when this operation is completed. |
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[1] | 112 | ************************************************************************************/ |
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| 113 | void sync_all_pages(); |
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| 114 | |
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| 115 | /************************************************************************************* |
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[22] | 116 | * This function sets the PG_DIRTY flag in the page descriptor, |
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| 117 | * and registers the page in the dirty list in PPM. |
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[23] | 118 | ************************************************************************************* |
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[1] | 119 | * @ page : pointer on page descriptor. |
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| 120 | * @ returns true if page was not dirty / returns false if page was dirty |
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| 121 | ************************************************************************************/ |
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| 122 | bool_t page_do_dirty( page_t * page ); |
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| 123 | |
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| 124 | /************************************************************************************* |
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[22] | 125 | * This function resets the PG_DIRTY flag in the page descriptor, |
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| 126 | * and removes the page from the dirty list in PPM. |
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[23] | 127 | ************************************************************************************* |
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[1] | 128 | * @ page : pointer on page descriptor. |
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[18] | 129 | * @ returns true if page was dirty / returns false if page was not dirty |
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[1] | 130 | ************************************************************************************/ |
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| 131 | bool_t page_undo_dirty( page_t * page ); |
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| 132 | |
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| 133 | /************************************************************************************* |
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[22] | 134 | * This function resets to 0 all bytes in a given page. |
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[23] | 135 | ************************************************************************************* |
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[1] | 136 | * @ page : pointer on page descriptor. |
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| 137 | ************************************************************************************/ |
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| 138 | void page_zero( page_t * page ); |
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| 139 | |
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| 140 | /************************************************************************************* |
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| 141 | * This blocking function set the PG_LOCKED flag on the page. |
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| 142 | * It deschedule if the page has already been locked by another thread, |
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[18] | 143 | * and returns only when the flag has been successfully set. |
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[23] | 144 | ************************************************************************************* |
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[1] | 145 | * @ page : pointer on page descriptor. |
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| 146 | ************************************************************************************/ |
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| 147 | void page_lock( page_t * page ); |
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| 148 | |
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| 149 | /************************************************************************************* |
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[22] | 150 | * This blocking function resets the PG_LOCKED flag on the page, if there is no |
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| 151 | * other waiting thread. If there is waiting thread(s), it activates the first |
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[1] | 152 | * waiting thread without modifying the PG_LOCKED flag. |
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[23] | 153 | ************************************************************************************* |
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[1] | 154 | * @ page : pointer on page descriptor. |
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| 155 | ************************************************************************************/ |
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| 156 | void page_unlock( page_t * page ); |
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| 157 | |
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| 158 | /************************************************************************************* |
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[22] | 159 | * This blocking function atomically increments the page refcount. |
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[23] | 160 | ************************************************************************************* |
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[1] | 161 | * @ page : pointer on page descriptor. |
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| 162 | ************************************************************************************/ |
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| 163 | inline void page_refcount_up( page_t * page ); |
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| 164 | |
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| 165 | /************************************************************************************* |
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[22] | 166 | * This blocking function atomically decrements the page refcount. |
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[23] | 167 | ************************************************************************************* |
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[1] | 168 | * @ page : pointer on page descriptor. |
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| 169 | ************************************************************************************/ |
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| 170 | inline void page_refcount_down( page_t * page ); |
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| 171 | |
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| 172 | /************************************************************************************* |
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| 173 | * This function display the values contained in a page descriptor. |
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[23] | 174 | ************************************************************************************* |
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| 175 | * @ page : pointer on page descriptor. |
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[1] | 176 | ************************************************************************************/ |
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| 177 | void page_print( page_t * page ); |
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| 178 | |
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| 179 | |
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| 180 | #endif /* _PAGE_H_ */ |
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