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 | |
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 | ||
cbe37d09 BP |
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 */ | |
68 | ||
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 */ | |
73 | ||
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 */ | |
1da177e4 LT |
78 | |
79 | /* | |
80 | * Global page accounting. One instance per CPU. Only unsigned longs are | |
81 | * allowed. | |
b09eb1c0 NP |
82 | * |
83 | * - Fields can be modified with xxx_page_state and xxx_page_state_zone at | |
84 | * any time safely (which protects the instance from modification by | |
85 | * interrupt. | |
86 | * - The __xxx_page_state variants can be used safely when interrupts are | |
87 | * disabled. | |
88 | * - The __xxx_page_state variants can be used if the field is only | |
89 | * modified from process context, or only modified from interrupt context. | |
90 | * In this case, the field should be commented here. | |
1da177e4 LT |
91 | */ |
92 | struct page_state { | |
93 | unsigned long nr_dirty; /* Dirty writeable pages */ | |
94 | unsigned long nr_writeback; /* Pages under writeback */ | |
95 | unsigned long nr_unstable; /* NFS unstable pages */ | |
96 | unsigned long nr_page_table_pages;/* Pages used for pagetables */ | |
b09eb1c0 NP |
97 | unsigned long nr_mapped; /* mapped into pagetables. |
98 | * only modified from process context */ | |
1da177e4 LT |
99 | unsigned long nr_slab; /* In slab */ |
100 | #define GET_PAGE_STATE_LAST nr_slab | |
101 | ||
102 | /* | |
103 | * The below are zeroed by get_page_state(). Use get_full_page_state() | |
104 | * to add up all these. | |
105 | */ | |
106 | unsigned long pgpgin; /* Disk reads */ | |
107 | unsigned long pgpgout; /* Disk writes */ | |
108 | unsigned long pswpin; /* swap reads */ | |
109 | unsigned long pswpout; /* swap writes */ | |
1da177e4 | 110 | |
9328b8fa | 111 | unsigned long pgalloc_high; /* page allocations */ |
1da177e4 | 112 | unsigned long pgalloc_normal; |
9328b8fa | 113 | unsigned long pgalloc_dma32; |
1da177e4 | 114 | unsigned long pgalloc_dma; |
9328b8fa | 115 | |
1da177e4 LT |
116 | unsigned long pgfree; /* page freeings */ |
117 | unsigned long pgactivate; /* pages moved inactive->active */ | |
118 | unsigned long pgdeactivate; /* pages moved active->inactive */ | |
119 | ||
120 | unsigned long pgfault; /* faults (major+minor) */ | |
121 | unsigned long pgmajfault; /* faults (major only) */ | |
9328b8fa | 122 | |
1da177e4 LT |
123 | unsigned long pgrefill_high; /* inspected in refill_inactive_zone */ |
124 | unsigned long pgrefill_normal; | |
9328b8fa | 125 | unsigned long pgrefill_dma32; |
1da177e4 LT |
126 | unsigned long pgrefill_dma; |
127 | ||
128 | unsigned long pgsteal_high; /* total highmem pages reclaimed */ | |
129 | unsigned long pgsteal_normal; | |
9328b8fa | 130 | unsigned long pgsteal_dma32; |
1da177e4 | 131 | unsigned long pgsteal_dma; |
9328b8fa | 132 | |
1da177e4 LT |
133 | unsigned long pgscan_kswapd_high;/* total highmem pages scanned */ |
134 | unsigned long pgscan_kswapd_normal; | |
9328b8fa | 135 | unsigned long pgscan_kswapd_dma32; |
1da177e4 | 136 | unsigned long pgscan_kswapd_dma; |
9328b8fa | 137 | |
1da177e4 LT |
138 | unsigned long pgscan_direct_high;/* total highmem pages scanned */ |
139 | unsigned long pgscan_direct_normal; | |
9328b8fa | 140 | unsigned long pgscan_direct_dma32; |
1da177e4 | 141 | unsigned long pgscan_direct_dma; |
1da177e4 | 142 | |
9328b8fa | 143 | unsigned long pginodesteal; /* pages reclaimed via inode freeing */ |
1da177e4 LT |
144 | unsigned long slabs_scanned; /* slab objects scanned */ |
145 | unsigned long kswapd_steal; /* pages reclaimed by kswapd */ | |
146 | unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */ | |
147 | unsigned long pageoutrun; /* kswapd's calls to page reclaim */ | |
148 | unsigned long allocstall; /* direct reclaim calls */ | |
149 | ||
150 | unsigned long pgrotated; /* pages rotated to tail of the LRU */ | |
edfbe2b0 | 151 | unsigned long nr_bounce; /* pages for bounce buffers */ |
1da177e4 LT |
152 | }; |
153 | ||
154 | extern void get_page_state(struct page_state *ret); | |
c07e02db | 155 | extern void get_page_state_node(struct page_state *ret, int node); |
1da177e4 | 156 | extern void get_full_page_state(struct page_state *ret); |
a74609fa NP |
157 | extern unsigned long read_page_state_offset(unsigned long offset); |
158 | extern void mod_page_state_offset(unsigned long offset, unsigned long delta); | |
159 | extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); | |
1da177e4 LT |
160 | |
161 | #define read_page_state(member) \ | |
a74609fa | 162 | read_page_state_offset(offsetof(struct page_state, member)) |
1da177e4 LT |
163 | |
164 | #define mod_page_state(member, delta) \ | |
a74609fa | 165 | mod_page_state_offset(offsetof(struct page_state, member), (delta)) |
1da177e4 | 166 | |
a74609fa NP |
167 | #define __mod_page_state(member, delta) \ |
168 | __mod_page_state_offset(offsetof(struct page_state, member), (delta)) | |
1da177e4 | 169 | |
a74609fa NP |
170 | #define inc_page_state(member) mod_page_state(member, 1UL) |
171 | #define dec_page_state(member) mod_page_state(member, 0UL - 1) | |
172 | #define add_page_state(member,delta) mod_page_state(member, (delta)) | |
173 | #define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta)) | |
174 | ||
175 | #define __inc_page_state(member) __mod_page_state(member, 1UL) | |
176 | #define __dec_page_state(member) __mod_page_state(member, 0UL - 1) | |
177 | #define __add_page_state(member,delta) __mod_page_state(member, (delta)) | |
178 | #define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta)) | |
179 | ||
180 | #define page_state(member) (*__page_state(offsetof(struct page_state, member))) | |
181 | ||
182 | #define state_zone_offset(zone, member) \ | |
183 | ({ \ | |
9328b8fa NP |
184 | unsigned offset; \ |
185 | if (is_highmem(zone)) \ | |
186 | offset = offsetof(struct page_state, member##_high); \ | |
187 | else if (is_normal(zone)) \ | |
188 | offset = offsetof(struct page_state, member##_normal); \ | |
189 | else if (is_dma32(zone)) \ | |
190 | offset = offsetof(struct page_state, member##_dma32); \ | |
191 | else \ | |
192 | offset = offsetof(struct page_state, member##_dma); \ | |
a74609fa NP |
193 | offset; \ |
194 | }) | |
195 | ||
196 | #define __mod_page_state_zone(zone, member, delta) \ | |
197 | do { \ | |
198 | __mod_page_state_offset(state_zone_offset(zone, member), (delta)); \ | |
199 | } while (0) | |
200 | ||
201 | #define mod_page_state_zone(zone, member, delta) \ | |
202 | do { \ | |
203 | mod_page_state_offset(state_zone_offset(zone, member), (delta)); \ | |
9328b8fa | 204 | } while (0) |
1da177e4 LT |
205 | |
206 | /* | |
207 | * Manipulation of page state flags | |
208 | */ | |
209 | #define PageLocked(page) \ | |
210 | test_bit(PG_locked, &(page)->flags) | |
211 | #define SetPageLocked(page) \ | |
212 | set_bit(PG_locked, &(page)->flags) | |
213 | #define TestSetPageLocked(page) \ | |
214 | test_and_set_bit(PG_locked, &(page)->flags) | |
215 | #define ClearPageLocked(page) \ | |
216 | clear_bit(PG_locked, &(page)->flags) | |
217 | #define TestClearPageLocked(page) \ | |
218 | test_and_clear_bit(PG_locked, &(page)->flags) | |
219 | ||
220 | #define PageError(page) test_bit(PG_error, &(page)->flags) | |
221 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) | |
222 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) | |
223 | ||
224 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) | |
225 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) | |
226 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) | |
227 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) | |
228 | ||
229 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) | |
230 | #ifndef SetPageUptodate | |
231 | #define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) | |
232 | #endif | |
233 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) | |
234 | ||
235 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) | |
236 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) | |
237 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) | |
238 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) | |
242e5468 | 239 | #define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags) |
1da177e4 LT |
240 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
241 | ||
242 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) | |
243 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) | |
244 | #define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags) | |
245 | #define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags) | |
246 | ||
247 | #define PageActive(page) test_bit(PG_active, &(page)->flags) | |
248 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) | |
249 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) | |
250 | #define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags) | |
251 | #define TestSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags) | |
252 | ||
253 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) | |
254 | #define SetPageSlab(page) set_bit(PG_slab, &(page)->flags) | |
255 | #define ClearPageSlab(page) clear_bit(PG_slab, &(page)->flags) | |
256 | #define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags) | |
257 | #define TestSetPageSlab(page) test_and_set_bit(PG_slab, &(page)->flags) | |
258 | ||
259 | #ifdef CONFIG_HIGHMEM | |
cbe37d09 | 260 | #define PageHighMem(page) is_highmem(page_zone(page)) |
1da177e4 LT |
261 | #else |
262 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ | |
263 | #endif | |
264 | ||
265 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) | |
266 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) | |
267 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) | |
268 | ||
269 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) | |
270 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) | |
271 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) | |
272 | #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) | |
273 | ||
274 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) | |
275 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) | |
276 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) | |
277 | #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) | |
278 | #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) | |
279 | ||
280 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) | |
281 | #define SetPageWriteback(page) \ | |
282 | do { \ | |
283 | if (!test_and_set_bit(PG_writeback, \ | |
284 | &(page)->flags)) \ | |
285 | inc_page_state(nr_writeback); \ | |
286 | } while (0) | |
287 | #define TestSetPageWriteback(page) \ | |
288 | ({ \ | |
289 | int ret; \ | |
290 | ret = test_and_set_bit(PG_writeback, \ | |
291 | &(page)->flags); \ | |
292 | if (!ret) \ | |
293 | inc_page_state(nr_writeback); \ | |
294 | ret; \ | |
295 | }) | |
296 | #define ClearPageWriteback(page) \ | |
297 | do { \ | |
298 | if (test_and_clear_bit(PG_writeback, \ | |
299 | &(page)->flags)) \ | |
300 | dec_page_state(nr_writeback); \ | |
301 | } while (0) | |
302 | #define TestClearPageWriteback(page) \ | |
303 | ({ \ | |
304 | int ret; \ | |
305 | ret = test_and_clear_bit(PG_writeback, \ | |
306 | &(page)->flags); \ | |
307 | if (ret) \ | |
308 | dec_page_state(nr_writeback); \ | |
309 | ret; \ | |
310 | }) | |
311 | ||
312 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) | |
313 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) | |
314 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) | |
315 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) | |
316 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) | |
317 | ||
318 | #define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) | |
319 | #define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) | |
320 | #define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) | |
321 | ||
322 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) | |
323 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) | |
324 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) | |
325 | ||
326 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) | |
327 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) | |
328 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) | |
329 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) | |
330 | ||
1da177e4 | 331 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
1da177e4 LT |
332 | #define SetPageCompound(page) set_bit(PG_compound, &(page)->flags) |
333 | #define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags) | |
334 | ||
335 | #ifdef CONFIG_SWAP | |
336 | #define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) | |
337 | #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) | |
338 | #define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) | |
339 | #else | |
340 | #define PageSwapCache(page) 0 | |
341 | #endif | |
342 | ||
343 | #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) | |
344 | #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) | |
345 | #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) | |
346 | ||
347 | struct page; /* forward declaration */ | |
348 | ||
349 | int test_clear_page_dirty(struct page *page); | |
350 | int test_clear_page_writeback(struct page *page); | |
351 | int test_set_page_writeback(struct page *page); | |
352 | ||
353 | static inline void clear_page_dirty(struct page *page) | |
354 | { | |
355 | test_clear_page_dirty(page); | |
356 | } | |
357 | ||
358 | static inline void set_page_writeback(struct page *page) | |
359 | { | |
360 | test_set_page_writeback(page); | |
361 | } | |
362 | ||
363 | #endif /* PAGE_FLAGS_H */ |