Commit | Line | Data |
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1da177e4 LT |
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 | |
91fc8ab3 AW |
51 | * locked- and dirty-page accounting. |
52 | * | |
53 | * The page flags field is split into two parts, the main flags area | |
54 | * which extends from the low bits upwards, and the fields area which | |
55 | * extends from the high bits downwards. | |
56 | * | |
57 | * | FIELD | ... | FLAGS | | |
58 | * N-1 ^ 0 | |
59 | * (N-FLAGS_RESERVED) | |
60 | * | |
61 | * The fields area is reserved for fields mapping zone, node and SPARSEMEM | |
62 | * section. The boundry between these two areas is defined by | |
63 | * FLAGS_RESERVED which defines the width of the fields section | |
64 | * (see linux/mmzone.h). New flags must _not_ overlap with this area. | |
1da177e4 LT |
65 | */ |
66 | #define PG_locked 0 /* Page is locked. Don't touch. */ | |
67 | #define PG_error 1 | |
68 | #define PG_referenced 2 | |
69 | #define PG_uptodate 3 | |
70 | ||
71 | #define PG_dirty 4 | |
72 | #define PG_lru 5 | |
73 | #define PG_active 6 | |
74 | #define PG_slab 7 /* slab debug (Suparna wants this) */ | |
75 | ||
cbe37d09 BP |
76 | #define PG_checked 8 /* kill me in 2.5.<early>. */ |
77 | #define PG_arch_1 9 | |
78 | #define PG_reserved 10 | |
79 | #define PG_private 11 /* Has something at ->private */ | |
80 | ||
81 | #define PG_writeback 12 /* Page is under writeback */ | |
82 | #define PG_nosave 13 /* Used for system suspend/resume */ | |
83 | #define PG_compound 14 /* Part of a compound page */ | |
84 | #define PG_swapcache 15 /* Swap page: swp_entry_t in private */ | |
85 | ||
86 | #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ | |
87 | #define PG_reclaim 17 /* To be reclaimed asap */ | |
88 | #define PG_nosave_free 18 /* Free, should not be written */ | |
676165a8 NP |
89 | #define PG_buddy 19 /* Page is free, on buddy lists */ |
90 | ||
91 | #define PG_uncached 20 /* Page has been mapped as uncached */ | |
1da177e4 LT |
92 | |
93 | /* | |
94 | * Global page accounting. One instance per CPU. Only unsigned longs are | |
95 | * allowed. | |
b09eb1c0 NP |
96 | * |
97 | * - Fields can be modified with xxx_page_state and xxx_page_state_zone at | |
98 | * any time safely (which protects the instance from modification by | |
99 | * interrupt. | |
100 | * - The __xxx_page_state variants can be used safely when interrupts are | |
101 | * disabled. | |
102 | * - The __xxx_page_state variants can be used if the field is only | |
9d414152 NP |
103 | * modified from process context and protected from preemption, or only |
104 | * modified from interrupt context. In this case, the field should be | |
105 | * commented here. | |
1da177e4 LT |
106 | */ |
107 | struct page_state { | |
108 | unsigned long nr_dirty; /* Dirty writeable pages */ | |
109 | unsigned long nr_writeback; /* Pages under writeback */ | |
110 | unsigned long nr_unstable; /* NFS unstable pages */ | |
111 | unsigned long nr_page_table_pages;/* Pages used for pagetables */ | |
b09eb1c0 NP |
112 | unsigned long nr_mapped; /* mapped into pagetables. |
113 | * only modified from process context */ | |
1da177e4 LT |
114 | unsigned long nr_slab; /* In slab */ |
115 | #define GET_PAGE_STATE_LAST nr_slab | |
116 | ||
117 | /* | |
118 | * The below are zeroed by get_page_state(). Use get_full_page_state() | |
119 | * to add up all these. | |
120 | */ | |
121 | unsigned long pgpgin; /* Disk reads */ | |
122 | unsigned long pgpgout; /* Disk writes */ | |
123 | unsigned long pswpin; /* swap reads */ | |
124 | unsigned long pswpout; /* swap writes */ | |
1da177e4 | 125 | |
9328b8fa | 126 | unsigned long pgalloc_high; /* page allocations */ |
1da177e4 | 127 | unsigned long pgalloc_normal; |
9328b8fa | 128 | unsigned long pgalloc_dma32; |
1da177e4 | 129 | unsigned long pgalloc_dma; |
9328b8fa | 130 | |
1da177e4 LT |
131 | unsigned long pgfree; /* page freeings */ |
132 | unsigned long pgactivate; /* pages moved inactive->active */ | |
133 | unsigned long pgdeactivate; /* pages moved active->inactive */ | |
134 | ||
135 | unsigned long pgfault; /* faults (major+minor) */ | |
136 | unsigned long pgmajfault; /* faults (major only) */ | |
9328b8fa | 137 | |
1da177e4 LT |
138 | unsigned long pgrefill_high; /* inspected in refill_inactive_zone */ |
139 | unsigned long pgrefill_normal; | |
9328b8fa | 140 | unsigned long pgrefill_dma32; |
1da177e4 LT |
141 | unsigned long pgrefill_dma; |
142 | ||
143 | unsigned long pgsteal_high; /* total highmem pages reclaimed */ | |
144 | unsigned long pgsteal_normal; | |
9328b8fa | 145 | unsigned long pgsteal_dma32; |
1da177e4 | 146 | unsigned long pgsteal_dma; |
9328b8fa | 147 | |
1da177e4 LT |
148 | unsigned long pgscan_kswapd_high;/* total highmem pages scanned */ |
149 | unsigned long pgscan_kswapd_normal; | |
9328b8fa | 150 | unsigned long pgscan_kswapd_dma32; |
1da177e4 | 151 | unsigned long pgscan_kswapd_dma; |
9328b8fa | 152 | |
1da177e4 LT |
153 | unsigned long pgscan_direct_high;/* total highmem pages scanned */ |
154 | unsigned long pgscan_direct_normal; | |
9328b8fa | 155 | unsigned long pgscan_direct_dma32; |
1da177e4 | 156 | unsigned long pgscan_direct_dma; |
1da177e4 | 157 | |
9328b8fa | 158 | unsigned long pginodesteal; /* pages reclaimed via inode freeing */ |
1da177e4 LT |
159 | unsigned long slabs_scanned; /* slab objects scanned */ |
160 | unsigned long kswapd_steal; /* pages reclaimed by kswapd */ | |
161 | unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */ | |
162 | unsigned long pageoutrun; /* kswapd's calls to page reclaim */ | |
163 | unsigned long allocstall; /* direct reclaim calls */ | |
164 | ||
165 | unsigned long pgrotated; /* pages rotated to tail of the LRU */ | |
edfbe2b0 | 166 | unsigned long nr_bounce; /* pages for bounce buffers */ |
1da177e4 LT |
167 | }; |
168 | ||
169 | extern void get_page_state(struct page_state *ret); | |
c07e02db | 170 | extern void get_page_state_node(struct page_state *ret, int node); |
1da177e4 | 171 | extern void get_full_page_state(struct page_state *ret); |
a74609fa NP |
172 | extern unsigned long read_page_state_offset(unsigned long offset); |
173 | extern void mod_page_state_offset(unsigned long offset, unsigned long delta); | |
174 | extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); | |
1da177e4 LT |
175 | |
176 | #define read_page_state(member) \ | |
a74609fa | 177 | read_page_state_offset(offsetof(struct page_state, member)) |
1da177e4 LT |
178 | |
179 | #define mod_page_state(member, delta) \ | |
a74609fa | 180 | mod_page_state_offset(offsetof(struct page_state, member), (delta)) |
1da177e4 | 181 | |
a74609fa NP |
182 | #define __mod_page_state(member, delta) \ |
183 | __mod_page_state_offset(offsetof(struct page_state, member), (delta)) | |
1da177e4 | 184 | |
a74609fa NP |
185 | #define inc_page_state(member) mod_page_state(member, 1UL) |
186 | #define dec_page_state(member) mod_page_state(member, 0UL - 1) | |
187 | #define add_page_state(member,delta) mod_page_state(member, (delta)) | |
188 | #define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta)) | |
189 | ||
190 | #define __inc_page_state(member) __mod_page_state(member, 1UL) | |
191 | #define __dec_page_state(member) __mod_page_state(member, 0UL - 1) | |
192 | #define __add_page_state(member,delta) __mod_page_state(member, (delta)) | |
193 | #define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta)) | |
194 | ||
195 | #define page_state(member) (*__page_state(offsetof(struct page_state, member))) | |
196 | ||
197 | #define state_zone_offset(zone, member) \ | |
198 | ({ \ | |
9328b8fa NP |
199 | unsigned offset; \ |
200 | if (is_highmem(zone)) \ | |
201 | offset = offsetof(struct page_state, member##_high); \ | |
202 | else if (is_normal(zone)) \ | |
203 | offset = offsetof(struct page_state, member##_normal); \ | |
204 | else if (is_dma32(zone)) \ | |
205 | offset = offsetof(struct page_state, member##_dma32); \ | |
206 | else \ | |
207 | offset = offsetof(struct page_state, member##_dma); \ | |
a74609fa NP |
208 | offset; \ |
209 | }) | |
210 | ||
211 | #define __mod_page_state_zone(zone, member, delta) \ | |
212 | do { \ | |
213 | __mod_page_state_offset(state_zone_offset(zone, member), (delta)); \ | |
214 | } while (0) | |
215 | ||
216 | #define mod_page_state_zone(zone, member, delta) \ | |
217 | do { \ | |
218 | mod_page_state_offset(state_zone_offset(zone, member), (delta)); \ | |
9328b8fa | 219 | } while (0) |
1da177e4 LT |
220 | |
221 | /* | |
222 | * Manipulation of page state flags | |
223 | */ | |
224 | #define PageLocked(page) \ | |
225 | test_bit(PG_locked, &(page)->flags) | |
226 | #define SetPageLocked(page) \ | |
227 | set_bit(PG_locked, &(page)->flags) | |
228 | #define TestSetPageLocked(page) \ | |
229 | test_and_set_bit(PG_locked, &(page)->flags) | |
230 | #define ClearPageLocked(page) \ | |
231 | clear_bit(PG_locked, &(page)->flags) | |
232 | #define TestClearPageLocked(page) \ | |
233 | test_and_clear_bit(PG_locked, &(page)->flags) | |
234 | ||
235 | #define PageError(page) test_bit(PG_error, &(page)->flags) | |
236 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) | |
237 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) | |
238 | ||
239 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) | |
240 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) | |
241 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) | |
242 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) | |
243 | ||
244 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) | |
245 | #ifndef SetPageUptodate | |
246 | #define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) | |
247 | #endif | |
248 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) | |
249 | ||
250 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) | |
251 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) | |
252 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) | |
253 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) | |
242e5468 | 254 | #define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags) |
1da177e4 LT |
255 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
256 | ||
1da177e4 | 257 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
8d438f96 NP |
258 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
259 | #define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags) | |
67453911 | 260 | #define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags) |
1da177e4 LT |
261 | |
262 | #define PageActive(page) test_bit(PG_active, &(page)->flags) | |
263 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) | |
264 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) | |
67453911 | 265 | #define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags) |
1da177e4 LT |
266 | |
267 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) | |
f205b2fe NP |
268 | #define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags) |
269 | #define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags) | |
1da177e4 LT |
270 | |
271 | #ifdef CONFIG_HIGHMEM | |
cbe37d09 | 272 | #define PageHighMem(page) is_highmem(page_zone(page)) |
1da177e4 LT |
273 | #else |
274 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ | |
275 | #endif | |
276 | ||
277 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) | |
278 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) | |
279 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) | |
280 | ||
281 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) | |
282 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) | |
283 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) | |
284 | #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) | |
285 | ||
286 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) | |
287 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) | |
288 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) | |
289 | #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) | |
290 | #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) | |
291 | ||
292 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) | |
293 | #define SetPageWriteback(page) \ | |
294 | do { \ | |
295 | if (!test_and_set_bit(PG_writeback, \ | |
296 | &(page)->flags)) \ | |
297 | inc_page_state(nr_writeback); \ | |
298 | } while (0) | |
299 | #define TestSetPageWriteback(page) \ | |
300 | ({ \ | |
301 | int ret; \ | |
302 | ret = test_and_set_bit(PG_writeback, \ | |
303 | &(page)->flags); \ | |
304 | if (!ret) \ | |
305 | inc_page_state(nr_writeback); \ | |
306 | ret; \ | |
307 | }) | |
308 | #define ClearPageWriteback(page) \ | |
309 | do { \ | |
310 | if (test_and_clear_bit(PG_writeback, \ | |
311 | &(page)->flags)) \ | |
312 | dec_page_state(nr_writeback); \ | |
313 | } while (0) | |
314 | #define TestClearPageWriteback(page) \ | |
315 | ({ \ | |
316 | int ret; \ | |
317 | ret = test_and_clear_bit(PG_writeback, \ | |
318 | &(page)->flags); \ | |
319 | if (ret) \ | |
320 | dec_page_state(nr_writeback); \ | |
321 | ret; \ | |
322 | }) | |
323 | ||
324 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) | |
325 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) | |
326 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) | |
327 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) | |
328 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) | |
329 | ||
330 | #define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) | |
331 | #define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) | |
332 | #define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) | |
333 | ||
676165a8 NP |
334 | #define PageBuddy(page) test_bit(PG_buddy, &(page)->flags) |
335 | #define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags) | |
336 | #define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags) | |
337 | ||
1da177e4 LT |
338 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
339 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) | |
340 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) | |
341 | ||
342 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) | |
343 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) | |
344 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) | |
345 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) | |
346 | ||
1da177e4 | 347 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
5e9dace8 NP |
348 | #define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags) |
349 | #define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags) | |
1da177e4 LT |
350 | |
351 | #ifdef CONFIG_SWAP | |
352 | #define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) | |
353 | #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) | |
354 | #define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) | |
355 | #else | |
356 | #define PageSwapCache(page) 0 | |
357 | #endif | |
358 | ||
359 | #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) | |
360 | #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) | |
361 | #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) | |
362 | ||
363 | struct page; /* forward declaration */ | |
364 | ||
365 | int test_clear_page_dirty(struct page *page); | |
366 | int test_clear_page_writeback(struct page *page); | |
367 | int test_set_page_writeback(struct page *page); | |
368 | ||
369 | static inline void clear_page_dirty(struct page *page) | |
370 | { | |
371 | test_clear_page_dirty(page); | |
372 | } | |
373 | ||
374 | static inline void set_page_writeback(struct page *page) | |
375 | { | |
376 | test_set_page_writeback(page); | |
377 | } | |
378 | ||
379 | #endif /* PAGE_FLAGS_H */ |