Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/swap.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * This file contains the default values for the opereation of the |
| 9 | * Linux VM subsystem. Fine-tuning documentation can be found in |
| 10 | * Documentation/sysctl/vm.txt. |
| 11 | * Started 18.12.91 |
| 12 | * Swap aging added 23.2.95, Stephen Tweedie. |
| 13 | * Buffermem limits added 12.3.98, Rik van Riel. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/kernel_stat.h> |
| 19 | #include <linux/swap.h> |
| 20 | #include <linux/mman.h> |
| 21 | #include <linux/pagemap.h> |
| 22 | #include <linux/pagevec.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/mm_inline.h> |
| 26 | #include <linux/buffer_head.h> /* for try_to_release_page() */ |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/percpu_counter.h> |
| 29 | #include <linux/percpu.h> |
| 30 | #include <linux/cpu.h> |
| 31 | #include <linux/notifier.h> |
| 32 | #include <linux/init.h> |
| 33 | |
| 34 | /* How many pages do we try to swap or page in/out together? */ |
| 35 | int page_cluster; |
| 36 | |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 37 | static void put_compound_page(struct page *page) |
| 38 | { |
| 39 | page = (struct page *)page_private(page); |
| 40 | if (put_page_testzero(page)) { |
| 41 | void (*dtor)(struct page *page); |
| 42 | |
Hugh Dickins | 41d78ba | 2006-02-14 13:52:58 -0800 | [diff] [blame] | 43 | dtor = (void (*)(struct page *))page[1].lru.next; |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 44 | (*dtor)(page); |
| 45 | } |
| 46 | } |
| 47 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | void put_page(struct page *page) |
| 49 | { |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 50 | if (unlikely(PageCompound(page))) |
| 51 | put_compound_page(page); |
| 52 | else if (put_page_testzero(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | __page_cache_release(page); |
| 54 | } |
| 55 | EXPORT_SYMBOL(put_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
| 57 | /* |
| 58 | * Writeback is about to end against a page which has been marked for immediate |
| 59 | * reclaim. If it still appears to be reclaimable, move it to the tail of the |
| 60 | * inactive list. The page still has PageWriteback set, which will pin it. |
| 61 | * |
| 62 | * We don't expect many pages to come through here, so don't bother batching |
| 63 | * things up. |
| 64 | * |
| 65 | * To avoid placing the page at the tail of the LRU while PG_writeback is still |
| 66 | * set, this function will clear PG_writeback before performing the page |
| 67 | * motion. Do that inside the lru lock because once PG_writeback is cleared |
| 68 | * we may not touch the page. |
| 69 | * |
| 70 | * Returns zero if it cleared PG_writeback. |
| 71 | */ |
| 72 | int rotate_reclaimable_page(struct page *page) |
| 73 | { |
| 74 | struct zone *zone; |
| 75 | unsigned long flags; |
| 76 | |
| 77 | if (PageLocked(page)) |
| 78 | return 1; |
| 79 | if (PageDirty(page)) |
| 80 | return 1; |
| 81 | if (PageActive(page)) |
| 82 | return 1; |
| 83 | if (!PageLRU(page)) |
| 84 | return 1; |
| 85 | |
| 86 | zone = page_zone(page); |
| 87 | spin_lock_irqsave(&zone->lru_lock, flags); |
| 88 | if (PageLRU(page) && !PageActive(page)) { |
| 89 | list_del(&page->lru); |
| 90 | list_add_tail(&page->lru, &zone->inactive_list); |
| 91 | inc_page_state(pgrotated); |
| 92 | } |
| 93 | if (!test_clear_page_writeback(page)) |
| 94 | BUG(); |
| 95 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * FIXME: speed this up? |
| 101 | */ |
| 102 | void fastcall activate_page(struct page *page) |
| 103 | { |
| 104 | struct zone *zone = page_zone(page); |
| 105 | |
| 106 | spin_lock_irq(&zone->lru_lock); |
| 107 | if (PageLRU(page) && !PageActive(page)) { |
| 108 | del_page_from_inactive_list(zone, page); |
| 109 | SetPageActive(page); |
| 110 | add_page_to_active_list(zone, page); |
| 111 | inc_page_state(pgactivate); |
| 112 | } |
| 113 | spin_unlock_irq(&zone->lru_lock); |
| 114 | } |
| 115 | |
| 116 | /* |
| 117 | * Mark a page as having seen activity. |
| 118 | * |
| 119 | * inactive,unreferenced -> inactive,referenced |
| 120 | * inactive,referenced -> active,unreferenced |
| 121 | * active,unreferenced -> active,referenced |
| 122 | */ |
| 123 | void fastcall mark_page_accessed(struct page *page) |
| 124 | { |
| 125 | if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) { |
| 126 | activate_page(page); |
| 127 | ClearPageReferenced(page); |
| 128 | } else if (!PageReferenced(page)) { |
| 129 | SetPageReferenced(page); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | EXPORT_SYMBOL(mark_page_accessed); |
| 134 | |
| 135 | /** |
| 136 | * lru_cache_add: add a page to the page lists |
| 137 | * @page: the page to add |
| 138 | */ |
| 139 | static DEFINE_PER_CPU(struct pagevec, lru_add_pvecs) = { 0, }; |
| 140 | static DEFINE_PER_CPU(struct pagevec, lru_add_active_pvecs) = { 0, }; |
| 141 | |
| 142 | void fastcall lru_cache_add(struct page *page) |
| 143 | { |
| 144 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs); |
| 145 | |
| 146 | page_cache_get(page); |
| 147 | if (!pagevec_add(pvec, page)) |
| 148 | __pagevec_lru_add(pvec); |
| 149 | put_cpu_var(lru_add_pvecs); |
| 150 | } |
| 151 | |
| 152 | void fastcall lru_cache_add_active(struct page *page) |
| 153 | { |
| 154 | struct pagevec *pvec = &get_cpu_var(lru_add_active_pvecs); |
| 155 | |
| 156 | page_cache_get(page); |
| 157 | if (!pagevec_add(pvec, page)) |
| 158 | __pagevec_lru_add_active(pvec); |
| 159 | put_cpu_var(lru_add_active_pvecs); |
| 160 | } |
| 161 | |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 162 | static void __lru_add_drain(int cpu) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | { |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 164 | struct pagevec *pvec = &per_cpu(lru_add_pvecs, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 166 | /* CPU is dead, so no locking needed. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | if (pagevec_count(pvec)) |
| 168 | __pagevec_lru_add(pvec); |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 169 | pvec = &per_cpu(lru_add_active_pvecs, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | if (pagevec_count(pvec)) |
| 171 | __pagevec_lru_add_active(pvec); |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 172 | } |
| 173 | |
| 174 | void lru_add_drain(void) |
| 175 | { |
| 176 | __lru_add_drain(get_cpu()); |
| 177 | put_cpu(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | } |
| 179 | |
Nick Piggin | 053837f | 2006-01-18 17:42:27 -0800 | [diff] [blame] | 180 | #ifdef CONFIG_NUMA |
| 181 | static void lru_add_drain_per_cpu(void *dummy) |
| 182 | { |
| 183 | lru_add_drain(); |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * Returns 0 for success |
| 188 | */ |
| 189 | int lru_add_drain_all(void) |
| 190 | { |
| 191 | return schedule_on_each_cpu(lru_add_drain_per_cpu, NULL); |
| 192 | } |
| 193 | |
| 194 | #else |
| 195 | |
| 196 | /* |
| 197 | * Returns 0 for success |
| 198 | */ |
| 199 | int lru_add_drain_all(void) |
| 200 | { |
| 201 | lru_add_drain(); |
| 202 | return 0; |
| 203 | } |
| 204 | #endif |
| 205 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | /* |
| 207 | * This path almost never happens for VM activity - pages are normally |
| 208 | * freed via pagevecs. But it gets used by networking. |
| 209 | */ |
| 210 | void fastcall __page_cache_release(struct page *page) |
| 211 | { |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 212 | if (PageLRU(page)) { |
| 213 | unsigned long flags; |
| 214 | struct zone *zone = page_zone(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 216 | spin_lock_irqsave(&zone->lru_lock, flags); |
Nick Piggin | 8d438f9 | 2006-03-22 00:07:59 -0800 | [diff] [blame] | 217 | BUG_ON(!PageLRU(page)); |
Nick Piggin | 6745391 | 2006-03-22 00:08:00 -0800 | [diff] [blame] | 218 | __ClearPageLRU(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | del_page_from_lru(zone, page); |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 220 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
| 221 | } |
| 222 | free_hot_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | EXPORT_SYMBOL(__page_cache_release); |
| 225 | |
| 226 | /* |
| 227 | * Batched page_cache_release(). Decrement the reference count on all the |
| 228 | * passed pages. If it fell to zero then remove the page from the LRU and |
| 229 | * free it. |
| 230 | * |
| 231 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it |
| 232 | * for the remainder of the operation. |
| 233 | * |
| 234 | * The locking in this function is against shrink_cache(): we recheck the |
| 235 | * page count inside the lock to see whether shrink_cache grabbed the page |
| 236 | * via the LRU. If it did, give up: shrink_cache will free it. |
| 237 | */ |
| 238 | void release_pages(struct page **pages, int nr, int cold) |
| 239 | { |
| 240 | int i; |
| 241 | struct pagevec pages_to_free; |
| 242 | struct zone *zone = NULL; |
| 243 | |
| 244 | pagevec_init(&pages_to_free, cold); |
| 245 | for (i = 0; i < nr; i++) { |
| 246 | struct page *page = pages[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | |
Nick Piggin | 8519fb3 | 2006-02-07 12:58:52 -0800 | [diff] [blame] | 248 | if (unlikely(PageCompound(page))) { |
| 249 | if (zone) { |
| 250 | spin_unlock_irq(&zone->lru_lock); |
| 251 | zone = NULL; |
| 252 | } |
| 253 | put_compound_page(page); |
| 254 | continue; |
| 255 | } |
| 256 | |
Nick Piggin | b581003 | 2005-10-29 18:16:12 -0700 | [diff] [blame] | 257 | if (!put_page_testzero(page)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | continue; |
| 259 | |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 260 | if (PageLRU(page)) { |
| 261 | struct zone *pagezone = page_zone(page); |
| 262 | if (pagezone != zone) { |
| 263 | if (zone) |
| 264 | spin_unlock_irq(&zone->lru_lock); |
| 265 | zone = pagezone; |
| 266 | spin_lock_irq(&zone->lru_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | } |
Nick Piggin | 8d438f9 | 2006-03-22 00:07:59 -0800 | [diff] [blame] | 268 | BUG_ON(!PageLRU(page)); |
Nick Piggin | 6745391 | 2006-03-22 00:08:00 -0800 | [diff] [blame] | 269 | __ClearPageLRU(page); |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 270 | del_page_from_lru(zone, page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | } |
Nick Piggin | 46453a6 | 2006-03-22 00:07:58 -0800 | [diff] [blame] | 272 | |
| 273 | if (!pagevec_add(&pages_to_free, page)) { |
| 274 | if (zone) { |
| 275 | spin_unlock_irq(&zone->lru_lock); |
| 276 | zone = NULL; |
| 277 | } |
| 278 | __pagevec_free(&pages_to_free); |
| 279 | pagevec_reinit(&pages_to_free); |
| 280 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | } |
| 282 | if (zone) |
| 283 | spin_unlock_irq(&zone->lru_lock); |
| 284 | |
| 285 | pagevec_free(&pages_to_free); |
| 286 | } |
| 287 | |
| 288 | /* |
| 289 | * The pages which we're about to release may be in the deferred lru-addition |
| 290 | * queues. That would prevent them from really being freed right now. That's |
| 291 | * OK from a correctness point of view but is inefficient - those pages may be |
| 292 | * cache-warm and we want to give them back to the page allocator ASAP. |
| 293 | * |
| 294 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() |
| 295 | * and __pagevec_lru_add_active() call release_pages() directly to avoid |
| 296 | * mutual recursion. |
| 297 | */ |
| 298 | void __pagevec_release(struct pagevec *pvec) |
| 299 | { |
| 300 | lru_add_drain(); |
| 301 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); |
| 302 | pagevec_reinit(pvec); |
| 303 | } |
| 304 | |
Steve French | 7f28570 | 2005-11-01 10:22:55 -0800 | [diff] [blame] | 305 | EXPORT_SYMBOL(__pagevec_release); |
| 306 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | /* |
| 308 | * pagevec_release() for pages which are known to not be on the LRU |
| 309 | * |
| 310 | * This function reinitialises the caller's pagevec. |
| 311 | */ |
| 312 | void __pagevec_release_nonlru(struct pagevec *pvec) |
| 313 | { |
| 314 | int i; |
| 315 | struct pagevec pages_to_free; |
| 316 | |
| 317 | pagevec_init(&pages_to_free, pvec->cold); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 319 | struct page *page = pvec->pages[i]; |
| 320 | |
| 321 | BUG_ON(PageLRU(page)); |
| 322 | if (put_page_testzero(page)) |
| 323 | pagevec_add(&pages_to_free, page); |
| 324 | } |
| 325 | pagevec_free(&pages_to_free); |
| 326 | pagevec_reinit(pvec); |
| 327 | } |
| 328 | |
| 329 | /* |
| 330 | * Add the passed pages to the LRU, then drop the caller's refcount |
| 331 | * on them. Reinitialises the caller's pagevec. |
| 332 | */ |
| 333 | void __pagevec_lru_add(struct pagevec *pvec) |
| 334 | { |
| 335 | int i; |
| 336 | struct zone *zone = NULL; |
| 337 | |
| 338 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 339 | struct page *page = pvec->pages[i]; |
| 340 | struct zone *pagezone = page_zone(page); |
| 341 | |
| 342 | if (pagezone != zone) { |
| 343 | if (zone) |
| 344 | spin_unlock_irq(&zone->lru_lock); |
| 345 | zone = pagezone; |
| 346 | spin_lock_irq(&zone->lru_lock); |
| 347 | } |
Nick Piggin | 8d438f9 | 2006-03-22 00:07:59 -0800 | [diff] [blame] | 348 | BUG_ON(PageLRU(page)); |
| 349 | SetPageLRU(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | add_page_to_inactive_list(zone, page); |
| 351 | } |
| 352 | if (zone) |
| 353 | spin_unlock_irq(&zone->lru_lock); |
| 354 | release_pages(pvec->pages, pvec->nr, pvec->cold); |
| 355 | pagevec_reinit(pvec); |
| 356 | } |
| 357 | |
| 358 | EXPORT_SYMBOL(__pagevec_lru_add); |
| 359 | |
| 360 | void __pagevec_lru_add_active(struct pagevec *pvec) |
| 361 | { |
| 362 | int i; |
| 363 | struct zone *zone = NULL; |
| 364 | |
| 365 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 366 | struct page *page = pvec->pages[i]; |
| 367 | struct zone *pagezone = page_zone(page); |
| 368 | |
| 369 | if (pagezone != zone) { |
| 370 | if (zone) |
| 371 | spin_unlock_irq(&zone->lru_lock); |
| 372 | zone = pagezone; |
| 373 | spin_lock_irq(&zone->lru_lock); |
| 374 | } |
Nick Piggin | 8d438f9 | 2006-03-22 00:07:59 -0800 | [diff] [blame] | 375 | BUG_ON(PageLRU(page)); |
| 376 | SetPageLRU(page); |
Nick Piggin | 4c84cac | 2006-03-22 00:08:00 -0800 | [diff] [blame] | 377 | BUG_ON(PageActive(page)); |
| 378 | SetPageActive(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | add_page_to_active_list(zone, page); |
| 380 | } |
| 381 | if (zone) |
| 382 | spin_unlock_irq(&zone->lru_lock); |
| 383 | release_pages(pvec->pages, pvec->nr, pvec->cold); |
| 384 | pagevec_reinit(pvec); |
| 385 | } |
| 386 | |
| 387 | /* |
| 388 | * Try to drop buffers from the pages in a pagevec |
| 389 | */ |
| 390 | void pagevec_strip(struct pagevec *pvec) |
| 391 | { |
| 392 | int i; |
| 393 | |
| 394 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 395 | struct page *page = pvec->pages[i]; |
| 396 | |
| 397 | if (PagePrivate(page) && !TestSetPageLocked(page)) { |
Christoph Lameter | 5b40dc7 | 2006-03-16 23:04:07 -0800 | [diff] [blame] | 398 | if (PagePrivate(page)) |
| 399 | try_to_release_page(page, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | unlock_page(page); |
| 401 | } |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | /** |
| 406 | * pagevec_lookup - gang pagecache lookup |
| 407 | * @pvec: Where the resulting pages are placed |
| 408 | * @mapping: The address_space to search |
| 409 | * @start: The starting page index |
| 410 | * @nr_pages: The maximum number of pages |
| 411 | * |
| 412 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages |
| 413 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a |
| 414 | * reference against the pages in @pvec. |
| 415 | * |
| 416 | * The search returns a group of mapping-contiguous pages with ascending |
| 417 | * indexes. There may be holes in the indices due to not-present pages. |
| 418 | * |
| 419 | * pagevec_lookup() returns the number of pages which were found. |
| 420 | */ |
| 421 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, |
| 422 | pgoff_t start, unsigned nr_pages) |
| 423 | { |
| 424 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); |
| 425 | return pagevec_count(pvec); |
| 426 | } |
| 427 | |
Christoph Hellwig | 78539fd | 2006-01-11 20:47:41 +1100 | [diff] [blame] | 428 | EXPORT_SYMBOL(pagevec_lookup); |
| 429 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
| 431 | pgoff_t *index, int tag, unsigned nr_pages) |
| 432 | { |
| 433 | pvec->nr = find_get_pages_tag(mapping, index, tag, |
| 434 | nr_pages, pvec->pages); |
| 435 | return pagevec_count(pvec); |
| 436 | } |
| 437 | |
Steve French | 7f28570 | 2005-11-01 10:22:55 -0800 | [diff] [blame] | 438 | EXPORT_SYMBOL(pagevec_lookup_tag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
| 440 | #ifdef CONFIG_SMP |
| 441 | /* |
| 442 | * We tolerate a little inaccuracy to avoid ping-ponging the counter between |
| 443 | * CPUs |
| 444 | */ |
| 445 | #define ACCT_THRESHOLD max(16, NR_CPUS * 2) |
| 446 | |
| 447 | static DEFINE_PER_CPU(long, committed_space) = 0; |
| 448 | |
| 449 | void vm_acct_memory(long pages) |
| 450 | { |
| 451 | long *local; |
| 452 | |
| 453 | preempt_disable(); |
| 454 | local = &__get_cpu_var(committed_space); |
| 455 | *local += pages; |
| 456 | if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) { |
| 457 | atomic_add(*local, &vm_committed_space); |
| 458 | *local = 0; |
| 459 | } |
| 460 | preempt_enable(); |
| 461 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
| 463 | #ifdef CONFIG_HOTPLUG_CPU |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | |
| 465 | /* Drop the CPU's cached committed space back into the central pool. */ |
| 466 | static int cpu_swap_callback(struct notifier_block *nfb, |
| 467 | unsigned long action, |
| 468 | void *hcpu) |
| 469 | { |
| 470 | long *committed; |
| 471 | |
| 472 | committed = &per_cpu(committed_space, (long)hcpu); |
| 473 | if (action == CPU_DEAD) { |
| 474 | atomic_add(*committed, &vm_committed_space); |
| 475 | *committed = 0; |
Andrew Morton | 80bfed9 | 2006-01-06 00:11:14 -0800 | [diff] [blame] | 476 | __lru_add_drain((long)hcpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | } |
| 478 | return NOTIFY_OK; |
| 479 | } |
| 480 | #endif /* CONFIG_HOTPLUG_CPU */ |
| 481 | #endif /* CONFIG_SMP */ |
| 482 | |
| 483 | #ifdef CONFIG_SMP |
| 484 | void percpu_counter_mod(struct percpu_counter *fbc, long amount) |
| 485 | { |
| 486 | long count; |
| 487 | long *pcount; |
| 488 | int cpu = get_cpu(); |
| 489 | |
| 490 | pcount = per_cpu_ptr(fbc->counters, cpu); |
| 491 | count = *pcount + amount; |
| 492 | if (count >= FBC_BATCH || count <= -FBC_BATCH) { |
| 493 | spin_lock(&fbc->lock); |
| 494 | fbc->count += count; |
Andrew Morton | e2bab3d | 2006-03-07 21:55:31 -0800 | [diff] [blame] | 495 | *pcount = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | spin_unlock(&fbc->lock); |
Andrew Morton | e2bab3d | 2006-03-07 21:55:31 -0800 | [diff] [blame] | 497 | } else { |
| 498 | *pcount = count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | put_cpu(); |
| 501 | } |
| 502 | EXPORT_SYMBOL(percpu_counter_mod); |
Andrew Morton | e2bab3d | 2006-03-07 21:55:31 -0800 | [diff] [blame] | 503 | |
| 504 | /* |
| 505 | * Add up all the per-cpu counts, return the result. This is a more accurate |
| 506 | * but much slower version of percpu_counter_read_positive() |
| 507 | */ |
| 508 | long percpu_counter_sum(struct percpu_counter *fbc) |
| 509 | { |
| 510 | long ret; |
| 511 | int cpu; |
| 512 | |
| 513 | spin_lock(&fbc->lock); |
| 514 | ret = fbc->count; |
KAMEZAWA Hiroyuki | 0a94502 | 2006-03-28 01:56:37 -0800 | [diff] [blame^] | 515 | for_each_possible_cpu(cpu) { |
Andrew Morton | e2bab3d | 2006-03-07 21:55:31 -0800 | [diff] [blame] | 516 | long *pcount = per_cpu_ptr(fbc->counters, cpu); |
| 517 | ret += *pcount; |
| 518 | } |
| 519 | spin_unlock(&fbc->lock); |
| 520 | return ret < 0 ? 0 : ret; |
| 521 | } |
| 522 | EXPORT_SYMBOL(percpu_counter_sum); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | #endif |
| 524 | |
| 525 | /* |
| 526 | * Perform any setup for the swap system |
| 527 | */ |
| 528 | void __init swap_setup(void) |
| 529 | { |
| 530 | unsigned long megs = num_physpages >> (20 - PAGE_SHIFT); |
| 531 | |
| 532 | /* Use a smaller cluster for small-memory machines */ |
| 533 | if (megs < 16) |
| 534 | page_cluster = 2; |
| 535 | else |
| 536 | page_cluster = 3; |
| 537 | /* |
| 538 | * Right now other parts of the system means that we |
| 539 | * _really_ don't want to cluster much more |
| 540 | */ |
| 541 | hotcpu_notifier(cpu_swap_callback, 0); |
| 542 | } |