Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Macros for manipulating and testing page->flags |
| 3 | */ |
| 4 | |
| 5 | #ifndef PAGE_FLAGS_H |
| 6 | #define PAGE_FLAGS_H |
| 7 | |
| 8 | #include <linux/percpu.h> |
| 9 | #include <linux/cache.h> |
| 10 | #include <asm/pgtable.h> |
| 11 | |
| 12 | /* |
| 13 | * Various page->flags bits: |
| 14 | * |
| 15 | * PG_reserved is set for special pages, which can never be swapped out. Some |
| 16 | * of them might not even exist (eg empty_bad_page)... |
| 17 | * |
| 18 | * The PG_private bitflag is set if page->private contains a valid value. |
| 19 | * |
| 20 | * During disk I/O, PG_locked is used. This bit is set before I/O and |
| 21 | * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks |
| 22 | * waiting for the I/O on this page to complete. |
| 23 | * |
| 24 | * PG_uptodate tells whether the page's contents is valid. When a read |
| 25 | * completes, the page becomes uptodate, unless a disk I/O error happened. |
| 26 | * |
| 27 | * For choosing which pages to swap out, inode pages carry a PG_referenced bit, |
| 28 | * which is set any time the system accesses that page through the (mapping, |
| 29 | * index) hash table. This referenced bit, together with the referenced bit |
| 30 | * in the page tables, is used to manipulate page->age and move the page across |
| 31 | * the active, inactive_dirty and inactive_clean lists. |
| 32 | * |
| 33 | * Note that the referenced bit, the page->lru list_head and the active, |
| 34 | * inactive_dirty and inactive_clean lists are protected by the |
| 35 | * zone->lru_lock, and *NOT* by the usual PG_locked bit! |
| 36 | * |
| 37 | * PG_error is set to indicate that an I/O error occurred on this page. |
| 38 | * |
| 39 | * PG_arch_1 is an architecture specific page state bit. The generic code |
| 40 | * guarantees that this bit is cleared for a page when it first is entered into |
| 41 | * the page cache. |
| 42 | * |
| 43 | * PG_highmem pages are not permanently mapped into the kernel virtual address |
| 44 | * space, they need to be kmapped separately for doing IO on the pages. The |
| 45 | * struct page (these bits with information) are always mapped into kernel |
| 46 | * address space... |
| 47 | */ |
| 48 | |
| 49 | /* |
| 50 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break |
| 51 | * locked- and dirty-page accounting. The top eight bits of page->flags are |
| 52 | * used for page->zone, so putting flag bits there doesn't work. |
| 53 | */ |
| 54 | #define PG_locked 0 /* Page is locked. Don't touch. */ |
| 55 | #define PG_error 1 |
| 56 | #define PG_referenced 2 |
| 57 | #define PG_uptodate 3 |
| 58 | |
| 59 | #define PG_dirty 4 |
| 60 | #define PG_lru 5 |
| 61 | #define PG_active 6 |
| 62 | #define PG_slab 7 /* slab debug (Suparna wants this) */ |
| 63 | |
Badari Pulavarty | cbe37d0 | 2005-06-21 17:14:52 -0700 | [diff] [blame] | 64 | #define PG_checked 8 /* kill me in 2.5.<early>. */ |
| 65 | #define PG_arch_1 9 |
| 66 | #define PG_reserved 10 |
| 67 | #define PG_private 11 /* Has something at ->private */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
Badari Pulavarty | cbe37d0 | 2005-06-21 17:14:52 -0700 | [diff] [blame] | 69 | #define PG_writeback 12 /* Page is under writeback */ |
| 70 | #define PG_nosave 13 /* Used for system suspend/resume */ |
| 71 | #define PG_compound 14 /* Part of a compound page */ |
| 72 | #define PG_swapcache 15 /* Swap page: swp_entry_t in private */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Badari Pulavarty | cbe37d0 | 2005-06-21 17:14:52 -0700 | [diff] [blame] | 74 | #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ |
| 75 | #define PG_reclaim 17 /* To be reclaimed asap */ |
| 76 | #define PG_nosave_free 18 /* Free, should not be written */ |
| 77 | #define PG_uncached 19 /* Page has been mapped as uncached */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | /* |
| 80 | * Global page accounting. One instance per CPU. Only unsigned longs are |
| 81 | * allowed. |
| 82 | */ |
| 83 | struct page_state { |
| 84 | unsigned long nr_dirty; /* Dirty writeable pages */ |
| 85 | unsigned long nr_writeback; /* Pages under writeback */ |
| 86 | unsigned long nr_unstable; /* NFS unstable pages */ |
| 87 | unsigned long nr_page_table_pages;/* Pages used for pagetables */ |
| 88 | unsigned long nr_mapped; /* mapped into pagetables */ |
| 89 | unsigned long nr_slab; /* In slab */ |
| 90 | #define GET_PAGE_STATE_LAST nr_slab |
| 91 | |
| 92 | /* |
| 93 | * The below are zeroed by get_page_state(). Use get_full_page_state() |
| 94 | * to add up all these. |
| 95 | */ |
| 96 | unsigned long pgpgin; /* Disk reads */ |
| 97 | unsigned long pgpgout; /* Disk writes */ |
| 98 | unsigned long pswpin; /* swap reads */ |
| 99 | unsigned long pswpout; /* swap writes */ |
| 100 | unsigned long pgalloc_high; /* page allocations */ |
| 101 | |
| 102 | unsigned long pgalloc_normal; |
| 103 | unsigned long pgalloc_dma; |
| 104 | unsigned long pgfree; /* page freeings */ |
| 105 | unsigned long pgactivate; /* pages moved inactive->active */ |
| 106 | unsigned long pgdeactivate; /* pages moved active->inactive */ |
| 107 | |
| 108 | unsigned long pgfault; /* faults (major+minor) */ |
| 109 | unsigned long pgmajfault; /* faults (major only) */ |
| 110 | unsigned long pgrefill_high; /* inspected in refill_inactive_zone */ |
| 111 | unsigned long pgrefill_normal; |
| 112 | unsigned long pgrefill_dma; |
| 113 | |
| 114 | unsigned long pgsteal_high; /* total highmem pages reclaimed */ |
| 115 | unsigned long pgsteal_normal; |
| 116 | unsigned long pgsteal_dma; |
| 117 | unsigned long pgscan_kswapd_high;/* total highmem pages scanned */ |
| 118 | unsigned long pgscan_kswapd_normal; |
| 119 | |
| 120 | unsigned long pgscan_kswapd_dma; |
| 121 | unsigned long pgscan_direct_high;/* total highmem pages scanned */ |
| 122 | unsigned long pgscan_direct_normal; |
| 123 | unsigned long pgscan_direct_dma; |
| 124 | unsigned long pginodesteal; /* pages reclaimed via inode freeing */ |
| 125 | |
| 126 | unsigned long slabs_scanned; /* slab objects scanned */ |
| 127 | unsigned long kswapd_steal; /* pages reclaimed by kswapd */ |
| 128 | unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */ |
| 129 | unsigned long pageoutrun; /* kswapd's calls to page reclaim */ |
| 130 | unsigned long allocstall; /* direct reclaim calls */ |
| 131 | |
| 132 | unsigned long pgrotated; /* pages rotated to tail of the LRU */ |
KAMEZAWA Hiroyuki | edfbe2b | 2005-05-01 08:58:37 -0700 | [diff] [blame] | 133 | unsigned long nr_bounce; /* pages for bounce buffers */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | }; |
| 135 | |
| 136 | extern void get_page_state(struct page_state *ret); |
| 137 | extern void get_full_page_state(struct page_state *ret); |
Benjamin LaHaise | c2f29ea | 2005-06-21 17:14:55 -0700 | [diff] [blame] | 138 | extern unsigned long __read_page_state(unsigned long offset); |
Benjamin LaHaise | 83e5d8f | 2005-06-21 17:14:54 -0700 | [diff] [blame] | 139 | extern void __mod_page_state(unsigned long offset, unsigned long delta); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | |
| 141 | #define read_page_state(member) \ |
| 142 | __read_page_state(offsetof(struct page_state, member)) |
| 143 | |
| 144 | #define mod_page_state(member, delta) \ |
| 145 | __mod_page_state(offsetof(struct page_state, member), (delta)) |
| 146 | |
| 147 | #define inc_page_state(member) mod_page_state(member, 1UL) |
| 148 | #define dec_page_state(member) mod_page_state(member, 0UL - 1) |
| 149 | #define add_page_state(member,delta) mod_page_state(member, (delta)) |
| 150 | #define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta)) |
| 151 | |
| 152 | #define mod_page_state_zone(zone, member, delta) \ |
| 153 | do { \ |
| 154 | unsigned offset; \ |
| 155 | if (is_highmem(zone)) \ |
| 156 | offset = offsetof(struct page_state, member##_high); \ |
| 157 | else if (is_normal(zone)) \ |
| 158 | offset = offsetof(struct page_state, member##_normal); \ |
| 159 | else \ |
| 160 | offset = offsetof(struct page_state, member##_dma); \ |
| 161 | __mod_page_state(offset, (delta)); \ |
| 162 | } while (0) |
| 163 | |
| 164 | /* |
| 165 | * Manipulation of page state flags |
| 166 | */ |
| 167 | #define PageLocked(page) \ |
| 168 | test_bit(PG_locked, &(page)->flags) |
| 169 | #define SetPageLocked(page) \ |
| 170 | set_bit(PG_locked, &(page)->flags) |
| 171 | #define TestSetPageLocked(page) \ |
| 172 | test_and_set_bit(PG_locked, &(page)->flags) |
| 173 | #define ClearPageLocked(page) \ |
| 174 | clear_bit(PG_locked, &(page)->flags) |
| 175 | #define TestClearPageLocked(page) \ |
| 176 | test_and_clear_bit(PG_locked, &(page)->flags) |
| 177 | |
| 178 | #define PageError(page) test_bit(PG_error, &(page)->flags) |
| 179 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) |
| 180 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) |
| 181 | |
| 182 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) |
| 183 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) |
| 184 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) |
| 185 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) |
| 186 | |
| 187 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) |
| 188 | #ifndef SetPageUptodate |
| 189 | #define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) |
| 190 | #endif |
| 191 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) |
| 192 | |
| 193 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) |
| 194 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) |
| 195 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) |
| 196 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) |
| 197 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
| 198 | |
| 199 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
| 200 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
| 201 | #define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags) |
| 202 | #define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags) |
| 203 | |
| 204 | #define PageActive(page) test_bit(PG_active, &(page)->flags) |
| 205 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) |
| 206 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) |
| 207 | #define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags) |
| 208 | #define TestSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags) |
| 209 | |
| 210 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) |
| 211 | #define SetPageSlab(page) set_bit(PG_slab, &(page)->flags) |
| 212 | #define ClearPageSlab(page) clear_bit(PG_slab, &(page)->flags) |
| 213 | #define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags) |
| 214 | #define TestSetPageSlab(page) test_and_set_bit(PG_slab, &(page)->flags) |
| 215 | |
| 216 | #ifdef CONFIG_HIGHMEM |
Badari Pulavarty | cbe37d0 | 2005-06-21 17:14:52 -0700 | [diff] [blame] | 217 | #define PageHighMem(page) is_highmem(page_zone(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | #else |
| 219 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ |
| 220 | #endif |
| 221 | |
| 222 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) |
| 223 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) |
| 224 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) |
| 225 | |
| 226 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) |
| 227 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) |
| 228 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) |
| 229 | #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) |
| 230 | |
| 231 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) |
| 232 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) |
| 233 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) |
| 234 | #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) |
| 235 | #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) |
| 236 | |
| 237 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) |
| 238 | #define SetPageWriteback(page) \ |
| 239 | do { \ |
| 240 | if (!test_and_set_bit(PG_writeback, \ |
| 241 | &(page)->flags)) \ |
| 242 | inc_page_state(nr_writeback); \ |
| 243 | } while (0) |
| 244 | #define TestSetPageWriteback(page) \ |
| 245 | ({ \ |
| 246 | int ret; \ |
| 247 | ret = test_and_set_bit(PG_writeback, \ |
| 248 | &(page)->flags); \ |
| 249 | if (!ret) \ |
| 250 | inc_page_state(nr_writeback); \ |
| 251 | ret; \ |
| 252 | }) |
| 253 | #define ClearPageWriteback(page) \ |
| 254 | do { \ |
| 255 | if (test_and_clear_bit(PG_writeback, \ |
| 256 | &(page)->flags)) \ |
| 257 | dec_page_state(nr_writeback); \ |
| 258 | } while (0) |
| 259 | #define TestClearPageWriteback(page) \ |
| 260 | ({ \ |
| 261 | int ret; \ |
| 262 | ret = test_and_clear_bit(PG_writeback, \ |
| 263 | &(page)->flags); \ |
| 264 | if (ret) \ |
| 265 | dec_page_state(nr_writeback); \ |
| 266 | ret; \ |
| 267 | }) |
| 268 | |
| 269 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) |
| 270 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) |
| 271 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) |
| 272 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) |
| 273 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) |
| 274 | |
| 275 | #define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) |
| 276 | #define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) |
| 277 | #define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) |
| 278 | |
| 279 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
| 280 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) |
| 281 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) |
| 282 | |
| 283 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) |
| 284 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) |
| 285 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) |
| 286 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) |
| 287 | |
| 288 | #ifdef CONFIG_HUGETLB_PAGE |
| 289 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
| 290 | #else |
| 291 | #define PageCompound(page) 0 |
| 292 | #endif |
| 293 | #define SetPageCompound(page) set_bit(PG_compound, &(page)->flags) |
| 294 | #define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags) |
| 295 | |
| 296 | #ifdef CONFIG_SWAP |
| 297 | #define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) |
| 298 | #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) |
| 299 | #define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) |
| 300 | #else |
| 301 | #define PageSwapCache(page) 0 |
| 302 | #endif |
| 303 | |
| 304 | #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) |
| 305 | #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) |
| 306 | #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) |
| 307 | |
| 308 | struct page; /* forward declaration */ |
| 309 | |
| 310 | int test_clear_page_dirty(struct page *page); |
| 311 | int test_clear_page_writeback(struct page *page); |
| 312 | int test_set_page_writeback(struct page *page); |
| 313 | |
| 314 | static inline void clear_page_dirty(struct page *page) |
| 315 | { |
| 316 | test_clear_page_dirty(page); |
| 317 | } |
| 318 | |
| 319 | static inline void set_page_writeback(struct page *page) |
| 320 | { |
| 321 | test_set_page_writeback(page); |
| 322 | } |
| 323 | |
| 324 | #endif /* PAGE_FLAGS_H */ |