Rev 422 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | /* |
| 2 | * Macros for manipulating and testing page->flags |
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| 3 | */ |
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| 4 | |||
| 5 | #ifndef PAGE_FLAGS_H |
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| 6 | #define PAGE_FLAGS_H |
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| 7 | |||
| 8 | #include <linux/percpu.h> |
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| 9 | #include <linux/cache.h> |
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| 10 | #include <asm/pgtable.h> |
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| 11 | |||
| 12 | /* |
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| 13 | * Various page->flags bits: |
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| 14 | * |
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| 15 | * PG_reserved is set for special pages, which can never be swapped out. Some |
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| 16 | * of them might not even exist (eg empty_bad_page)... |
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| 17 | * |
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| 18 | * The PG_private bitflag is set if page->private contains a valid value. |
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| 19 | * |
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| 20 | * During disk I/O, PG_locked is used. This bit is set before I/O and |
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| 21 | * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks |
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| 22 | * waiting for the I/O on this page to complete. |
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| 23 | * |
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| 24 | * PG_uptodate tells whether the page's contents is valid. When a read |
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| 25 | * completes, the page becomes uptodate, unless a disk I/O error happened. |
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| 26 | * |
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| 27 | * For choosing which pages to swap out, inode pages carry a PG_referenced bit, |
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| 28 | * which is set any time the system accesses that page through the (mapping, |
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| 29 | * index) hash table. This referenced bit, together with the referenced bit |
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| 30 | * in the page tables, is used to manipulate page->age and move the page across |
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| 31 | * the active, inactive_dirty and inactive_clean lists. |
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| 32 | * |
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| 33 | * Note that the referenced bit, the page->lru list_head and the active, |
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| 34 | * inactive_dirty and inactive_clean lists are protected by the |
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| 35 | * zone->lru_lock, and *NOT* by the usual PG_locked bit! |
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| 36 | * |
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| 37 | * PG_error is set to indicate that an I/O error occurred on this page. |
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| 38 | * |
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| 39 | * PG_arch_1 is an architecture specific page state bit. The generic code |
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| 40 | * guarantees that this bit is cleared for a page when it first is entered into |
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| 41 | * the page cache. |
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| 42 | * |
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| 43 | * PG_highmem pages are not permanently mapped into the kernel virtual address |
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| 44 | * space, they need to be kmapped separately for doing IO on the pages. The |
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| 45 | * struct page (these bits with information) are always mapped into kernel |
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| 46 | * address space... |
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| 47 | */ |
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| 48 | |||
| 49 | /* |
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| 50 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break |
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| 51 | * locked- and dirty-page accounting. The top eight bits of page->flags are |
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| 52 | * used for page->zone, so putting flag bits there doesn't work. |
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| 53 | */ |
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| 54 | #define PG_locked 0 /* Page is locked. Don't touch. */ |
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| 55 | #define PG_error 1 |
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| 56 | #define PG_referenced 2 |
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| 57 | #define PG_uptodate 3 |
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| 58 | |||
| 59 | #define PG_dirty 4 |
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| 60 | #define PG_lru 5 |
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| 61 | #define PG_active 6 |
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| 62 | #define PG_slab 7 /* slab debug (Suparna wants this) */ |
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| 63 | |||
| 64 | #define PG_highmem 8 |
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| 65 | #define PG_checked 9 /* kill me in 2.5.<early>. */ |
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| 66 | #define PG_arch_1 10 |
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| 67 | #define PG_reserved 11 |
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| 68 | |||
| 69 | #define PG_private 12 /* Has something at ->private */ |
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| 70 | #define PG_writeback 13 /* Page is under writeback */ |
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| 71 | #define PG_nosave 14 /* Used for system suspend/resume */ |
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| 72 | #define PG_chainlock 15 /* lock bit for ->pte_chain */ |
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| 73 | |||
| 74 | #define PG_direct 16 /* ->pte_chain points directly at pte */ |
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| 75 | #define PG_mappedtodisk 17 /* Has blocks allocated on-disk */ |
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| 76 | #define PG_reclaim 18 /* To be reclaimed asap */ |
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| 77 | #define PG_compound 19 /* Part of a compound page */ |
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| 78 | |||
| 79 | |||
| 80 | /* |
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| 81 | * Global page accounting. One instance per CPU. Only unsigned longs are |
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| 82 | * allowed. |
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| 83 | */ |
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| 84 | struct page_state { |
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| 85 | unsigned long nr_dirty; /* Dirty writeable pages */ |
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| 86 | unsigned long nr_writeback; /* Pages under writeback */ |
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| 87 | unsigned long nr_unstable; /* NFS unstable pages */ |
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| 88 | unsigned long nr_page_table_pages;/* Pages used for pagetables */ |
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| 89 | unsigned long nr_mapped; /* mapped into pagetables */ |
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| 90 | unsigned long nr_slab; /* In slab */ |
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| 91 | #define GET_PAGE_STATE_LAST nr_slab |
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| 92 | |||
| 93 | /* |
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| 94 | * The below are zeroed by get_page_state(). Use get_full_page_state() |
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| 95 | * to add up all these. |
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| 96 | */ |
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| 97 | unsigned long pgpgin; /* Disk reads */ |
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| 98 | unsigned long pgpgout; /* Disk writes */ |
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| 99 | unsigned long pswpin; /* swap reads */ |
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| 100 | unsigned long pswpout; /* swap writes */ |
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| 101 | unsigned long pgalloc; /* page allocations */ |
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| 102 | |||
| 103 | unsigned long pgfree; /* page freeings */ |
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| 104 | unsigned long pgactivate; /* pages moved inactive->active */ |
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| 105 | unsigned long pgdeactivate; /* pages moved active->inactive */ |
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| 106 | unsigned long pgfault; /* faults (major+minor) */ |
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| 107 | unsigned long pgmajfault; /* faults (major only) */ |
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| 108 | |||
| 109 | unsigned long pgscan; /* pages scanned by page reclaim */ |
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| 110 | unsigned long pgrefill; /* inspected in refill_inactive_zone */ |
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| 111 | unsigned long pgsteal; /* total pages reclaimed */ |
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| 112 | unsigned long pginodesteal; /* pages reclaimed via inode freeing */ |
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| 113 | unsigned long kswapd_steal; /* pages reclaimed by kswapd */ |
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| 114 | |||
| 115 | unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */ |
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| 116 | unsigned long pageoutrun; /* kswapd's calls to page reclaim */ |
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| 117 | unsigned long allocstall; /* direct reclaim calls */ |
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| 118 | unsigned long pgrotated; /* pages rotated to tail of the LRU */ |
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| 119 | } ____cacheline_aligned; |
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| 120 | |||
| 121 | DECLARE_PER_CPU(struct page_state, page_states); |
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| 122 | |||
| 123 | extern void get_page_state(struct page_state *ret); |
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| 124 | extern void get_full_page_state(struct page_state *ret); |
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| 125 | |||
| 126 | #define mod_page_state(member, delta) \ |
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| 127 | do { \ |
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| 128 | unsigned long flags; \ |
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| 129 | local_irq_save(flags); \ |
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| 130 | __get_cpu_var(page_states).member += (delta); \ |
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| 131 | local_irq_restore(flags); \ |
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| 132 | } while (0) |
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| 133 | |||
| 134 | #define inc_page_state(member) mod_page_state(member, 1UL) |
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| 135 | #define dec_page_state(member) mod_page_state(member, 0UL - 1) |
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| 136 | #define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta)) |
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| 137 | |||
| 138 | |||
| 139 | /* |
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| 140 | * Manipulation of page state flags |
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| 141 | */ |
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| 142 | #define PageLocked(page) \ |
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| 143 | test_bit(PG_locked, &(page)->flags) |
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| 144 | #define SetPageLocked(page) \ |
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| 145 | set_bit(PG_locked, &(page)->flags) |
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| 146 | #define TestSetPageLocked(page) \ |
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| 147 | test_and_set_bit(PG_locked, &(page)->flags) |
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| 148 | #define ClearPageLocked(page) \ |
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| 149 | clear_bit(PG_locked, &(page)->flags) |
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| 150 | #define TestClearPageLocked(page) \ |
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| 151 | test_and_clear_bit(PG_locked, &(page)->flags) |
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| 152 | |||
| 153 | #define PageError(page) test_bit(PG_error, &(page)->flags) |
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| 154 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) |
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| 155 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) |
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| 156 | |||
| 157 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) |
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| 158 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) |
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| 159 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) |
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| 160 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) |
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| 161 | |||
| 162 | #ifndef arch_set_page_uptodate |
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| 163 | #define arch_set_page_uptodate(page) do { } while (0) |
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| 164 | #endif |
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| 165 | |||
| 166 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) |
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| 167 | #define SetPageUptodate(page) \ |
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| 168 | do { \ |
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| 169 | arch_set_page_uptodate(page); \ |
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| 170 | set_bit(PG_uptodate, &(page)->flags); \ |
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| 171 | } while (0) |
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| 172 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) |
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| 173 | |||
| 174 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) |
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| 175 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) |
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| 176 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) |
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| 177 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) |
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| 178 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
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| 179 | |||
| 180 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
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| 181 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
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| 182 | #define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags) |
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| 183 | #define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags) |
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| 184 | |||
| 185 | #define PageActive(page) test_bit(PG_active, &(page)->flags) |
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| 186 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) |
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| 187 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) |
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| 188 | #define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags) |
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| 189 | #define TestSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags) |
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| 190 | |||
| 191 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) |
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| 192 | #define SetPageSlab(page) set_bit(PG_slab, &(page)->flags) |
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| 193 | #define ClearPageSlab(page) clear_bit(PG_slab, &(page)->flags) |
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| 194 | #define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags) |
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| 195 | #define TestSetPageSlab(page) test_and_set_bit(PG_slab, &(page)->flags) |
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| 196 | |||
| 197 | #ifdef CONFIG_HIGHMEM |
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| 198 | #define PageHighMem(page) test_bit(PG_highmem, &(page)->flags) |
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| 199 | #else |
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| 200 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ |
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| 201 | #endif |
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| 202 | |||
| 203 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) |
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| 204 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) |
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| 205 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) |
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| 206 | |||
| 207 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) |
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| 208 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) |
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| 209 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) |
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| 210 | |||
| 211 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) |
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| 212 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) |
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| 213 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) |
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| 214 | |||
| 215 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) |
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| 216 | #define SetPageWriteback(page) \ |
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| 217 | do { \ |
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| 218 | if (!test_and_set_bit(PG_writeback, \ |
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| 219 | &(page)->flags)) \ |
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| 220 | inc_page_state(nr_writeback); \ |
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| 221 | } while (0) |
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| 222 | #define TestSetPageWriteback(page) \ |
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| 223 | ({ \ |
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| 224 | int ret; \ |
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| 225 | ret = test_and_set_bit(PG_writeback, \ |
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| 226 | &(page)->flags); \ |
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| 227 | if (!ret) \ |
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| 228 | inc_page_state(nr_writeback); \ |
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| 229 | ret; \ |
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| 230 | }) |
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| 231 | #define ClearPageWriteback(page) \ |
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| 232 | do { \ |
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| 233 | if (test_and_clear_bit(PG_writeback, \ |
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| 234 | &(page)->flags)) \ |
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| 235 | dec_page_state(nr_writeback); \ |
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| 236 | } while (0) |
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| 237 | #define TestClearPageWriteback(page) \ |
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| 238 | ({ \ |
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| 239 | int ret; \ |
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| 240 | ret = test_and_clear_bit(PG_writeback, \ |
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| 241 | &(page)->flags); \ |
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| 242 | if (ret) \ |
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| 243 | dec_page_state(nr_writeback); \ |
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| 244 | ret; \ |
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| 245 | }) |
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| 246 | |||
| 247 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) |
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| 248 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) |
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| 249 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) |
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| 250 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) |
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| 251 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) |
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| 252 | |||
| 253 | #define PageDirect(page) test_bit(PG_direct, &(page)->flags) |
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| 254 | #define SetPageDirect(page) set_bit(PG_direct, &(page)->flags) |
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| 255 | #define TestSetPageDirect(page) test_and_set_bit(PG_direct, &(page)->flags) |
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| 256 | #define ClearPageDirect(page) clear_bit(PG_direct, &(page)->flags) |
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| 257 | #define TestClearPageDirect(page) test_and_clear_bit(PG_direct, &(page)->flags) |
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| 258 | |||
| 259 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
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| 260 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) |
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| 261 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) |
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| 262 | |||
| 263 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) |
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| 264 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) |
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| 265 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) |
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| 266 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) |
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| 267 | |||
| 268 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
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| 269 | #define SetPageCompound(page) set_bit(PG_compound, &(page)->flags) |
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| 270 | #define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags) |
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| 271 | |||
| 272 | /* |
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| 273 | * The PageSwapCache predicate doesn't use a PG_flag at this time, |
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| 274 | * but it may again do so one day. |
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| 275 | */ |
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| 276 | #ifdef CONFIG_SWAP |
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| 277 | extern struct address_space swapper_space; |
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| 278 | #define PageSwapCache(page) ((page)->mapping == &swapper_space) |
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| 279 | #else |
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| 280 | #define PageSwapCache(page) 0 |
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| 281 | #endif |
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| 282 | |||
| 283 | struct page; /* forward declaration */ |
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| 284 | |||
| 285 | int test_clear_page_dirty(struct page *page); |
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| 286 | |||
| 287 | static inline void clear_page_dirty(struct page *page) |
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| 288 | { |
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| 289 | test_clear_page_dirty(page); |
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| 290 | } |
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| 291 | |||
| 292 | #endif /* PAGE_FLAGS_H */ |