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1da177e4 LT |
1 | /* |
2 | * linux/mm/swap.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
5 | */ | |
6 | ||
7 | /* | |
183ff22b | 8 | * This file contains the default values for the operation of the |
1da177e4 LT |
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() */ | |
1da177e4 LT |
27 | #include <linux/percpu_counter.h> |
28 | #include <linux/percpu.h> | |
29 | #include <linux/cpu.h> | |
30 | #include <linux/notifier.h> | |
e0bf68dd | 31 | #include <linux/backing-dev.h> |
66e1707b | 32 | #include <linux/memcontrol.h> |
1da177e4 LT |
33 | |
34 | /* How many pages do we try to swap or page in/out together? */ | |
35 | int page_cluster; | |
36 | ||
f04e9ebb | 37 | static DEFINE_PER_CPU(struct pagevec[NR_LRU_LISTS], lru_add_pvecs); |
f84f9504 | 38 | static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs); |
902aaed0 | 39 | |
b221385b AB |
40 | /* |
41 | * This path almost never happens for VM activity - pages are normally | |
42 | * freed via pagevecs. But it gets used by networking. | |
43 | */ | |
920c7a5d | 44 | static void __page_cache_release(struct page *page) |
b221385b AB |
45 | { |
46 | if (PageLRU(page)) { | |
47 | unsigned long flags; | |
48 | struct zone *zone = page_zone(page); | |
49 | ||
50 | spin_lock_irqsave(&zone->lru_lock, flags); | |
51 | VM_BUG_ON(!PageLRU(page)); | |
52 | __ClearPageLRU(page); | |
53 | del_page_from_lru(zone, page); | |
54 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
55 | } | |
56 | free_hot_page(page); | |
57 | } | |
58 | ||
8519fb30 | 59 | static void put_compound_page(struct page *page) |
1da177e4 | 60 | { |
d85f3385 | 61 | page = compound_head(page); |
8519fb30 | 62 | if (put_page_testzero(page)) { |
33f2ef89 | 63 | compound_page_dtor *dtor; |
1da177e4 | 64 | |
33f2ef89 | 65 | dtor = get_compound_page_dtor(page); |
8519fb30 | 66 | (*dtor)(page); |
1da177e4 | 67 | } |
8519fb30 NP |
68 | } |
69 | ||
70 | void put_page(struct page *page) | |
71 | { | |
72 | if (unlikely(PageCompound(page))) | |
73 | put_compound_page(page); | |
74 | else if (put_page_testzero(page)) | |
1da177e4 LT |
75 | __page_cache_release(page); |
76 | } | |
77 | EXPORT_SYMBOL(put_page); | |
1da177e4 | 78 | |
1d7ea732 | 79 | /** |
7682486b RD |
80 | * put_pages_list() - release a list of pages |
81 | * @pages: list of pages threaded on page->lru | |
1d7ea732 AZ |
82 | * |
83 | * Release a list of pages which are strung together on page.lru. Currently | |
84 | * used by read_cache_pages() and related error recovery code. | |
1d7ea732 AZ |
85 | */ |
86 | void put_pages_list(struct list_head *pages) | |
87 | { | |
88 | while (!list_empty(pages)) { | |
89 | struct page *victim; | |
90 | ||
91 | victim = list_entry(pages->prev, struct page, lru); | |
92 | list_del(&victim->lru); | |
93 | page_cache_release(victim); | |
94 | } | |
95 | } | |
96 | EXPORT_SYMBOL(put_pages_list); | |
97 | ||
902aaed0 HH |
98 | /* |
99 | * pagevec_move_tail() must be called with IRQ disabled. | |
100 | * Otherwise this may cause nasty races. | |
101 | */ | |
102 | static void pagevec_move_tail(struct pagevec *pvec) | |
103 | { | |
104 | int i; | |
105 | int pgmoved = 0; | |
106 | struct zone *zone = NULL; | |
107 | ||
108 | for (i = 0; i < pagevec_count(pvec); i++) { | |
109 | struct page *page = pvec->pages[i]; | |
110 | struct zone *pagezone = page_zone(page); | |
111 | ||
112 | if (pagezone != zone) { | |
113 | if (zone) | |
114 | spin_unlock(&zone->lru_lock); | |
115 | zone = pagezone; | |
116 | spin_lock(&zone->lru_lock); | |
117 | } | |
118 | if (PageLRU(page) && !PageActive(page)) { | |
b69408e8 | 119 | list_move_tail(&page->lru, &zone->lru[LRU_INACTIVE].list); |
902aaed0 HH |
120 | pgmoved++; |
121 | } | |
122 | } | |
123 | if (zone) | |
124 | spin_unlock(&zone->lru_lock); | |
125 | __count_vm_events(PGROTATED, pgmoved); | |
126 | release_pages(pvec->pages, pvec->nr, pvec->cold); | |
127 | pagevec_reinit(pvec); | |
128 | } | |
129 | ||
1da177e4 LT |
130 | /* |
131 | * Writeback is about to end against a page which has been marked for immediate | |
132 | * reclaim. If it still appears to be reclaimable, move it to the tail of the | |
902aaed0 | 133 | * inactive list. |
1da177e4 | 134 | */ |
ac6aadb2 | 135 | void rotate_reclaimable_page(struct page *page) |
1da177e4 | 136 | { |
ac6aadb2 MS |
137 | if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) && |
138 | PageLRU(page)) { | |
139 | struct pagevec *pvec; | |
140 | unsigned long flags; | |
141 | ||
142 | page_cache_get(page); | |
143 | local_irq_save(flags); | |
144 | pvec = &__get_cpu_var(lru_rotate_pvecs); | |
145 | if (!pagevec_add(pvec, page)) | |
146 | pagevec_move_tail(pvec); | |
147 | local_irq_restore(flags); | |
148 | } | |
1da177e4 LT |
149 | } |
150 | ||
151 | /* | |
152 | * FIXME: speed this up? | |
153 | */ | |
920c7a5d | 154 | void activate_page(struct page *page) |
1da177e4 LT |
155 | { |
156 | struct zone *zone = page_zone(page); | |
157 | ||
158 | spin_lock_irq(&zone->lru_lock); | |
159 | if (PageLRU(page) && !PageActive(page)) { | |
160 | del_page_from_inactive_list(zone, page); | |
161 | SetPageActive(page); | |
162 | add_page_to_active_list(zone, page); | |
f8891e5e | 163 | __count_vm_event(PGACTIVATE); |
427d5416 | 164 | mem_cgroup_move_lists(page, true); |
1da177e4 LT |
165 | } |
166 | spin_unlock_irq(&zone->lru_lock); | |
167 | } | |
168 | ||
169 | /* | |
170 | * Mark a page as having seen activity. | |
171 | * | |
172 | * inactive,unreferenced -> inactive,referenced | |
173 | * inactive,referenced -> active,unreferenced | |
174 | * active,unreferenced -> active,referenced | |
175 | */ | |
920c7a5d | 176 | void mark_page_accessed(struct page *page) |
1da177e4 LT |
177 | { |
178 | if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) { | |
179 | activate_page(page); | |
180 | ClearPageReferenced(page); | |
181 | } else if (!PageReferenced(page)) { | |
182 | SetPageReferenced(page); | |
183 | } | |
184 | } | |
185 | ||
186 | EXPORT_SYMBOL(mark_page_accessed); | |
187 | ||
f04e9ebb | 188 | void __lru_cache_add(struct page *page, enum lru_list lru) |
1da177e4 | 189 | { |
f04e9ebb | 190 | struct pagevec *pvec = &get_cpu_var(lru_add_pvecs)[lru]; |
1da177e4 LT |
191 | |
192 | page_cache_get(page); | |
193 | if (!pagevec_add(pvec, page)) | |
f04e9ebb | 194 | ____pagevec_lru_add(pvec, lru); |
1da177e4 LT |
195 | put_cpu_var(lru_add_pvecs); |
196 | } | |
197 | ||
f04e9ebb KM |
198 | /** |
199 | * lru_cache_add_lru - add a page to a page list | |
200 | * @page: the page to be added to the LRU. | |
201 | * @lru: the LRU list to which the page is added. | |
202 | */ | |
203 | void lru_cache_add_lru(struct page *page, enum lru_list lru) | |
1da177e4 | 204 | { |
f04e9ebb KM |
205 | if (PageActive(page)) { |
206 | ClearPageActive(page); | |
207 | } | |
1da177e4 | 208 | |
f04e9ebb KM |
209 | VM_BUG_ON(PageLRU(page) || PageActive(page)); |
210 | __lru_cache_add(page, lru); | |
1da177e4 LT |
211 | } |
212 | ||
902aaed0 HH |
213 | /* |
214 | * Drain pages out of the cpu's pagevecs. | |
215 | * Either "cpu" is the current CPU, and preemption has already been | |
216 | * disabled; or "cpu" is being hot-unplugged, and is already dead. | |
217 | */ | |
218 | static void drain_cpu_pagevecs(int cpu) | |
1da177e4 | 219 | { |
f04e9ebb | 220 | struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); |
902aaed0 | 221 | struct pagevec *pvec; |
f04e9ebb | 222 | int lru; |
1da177e4 | 223 | |
f04e9ebb KM |
224 | for_each_lru(lru) { |
225 | pvec = &pvecs[lru - LRU_BASE]; | |
226 | if (pagevec_count(pvec)) | |
227 | ____pagevec_lru_add(pvec, lru); | |
228 | } | |
902aaed0 HH |
229 | |
230 | pvec = &per_cpu(lru_rotate_pvecs, cpu); | |
231 | if (pagevec_count(pvec)) { | |
232 | unsigned long flags; | |
233 | ||
234 | /* No harm done if a racing interrupt already did this */ | |
235 | local_irq_save(flags); | |
236 | pagevec_move_tail(pvec); | |
237 | local_irq_restore(flags); | |
238 | } | |
80bfed90 AM |
239 | } |
240 | ||
241 | void lru_add_drain(void) | |
242 | { | |
902aaed0 | 243 | drain_cpu_pagevecs(get_cpu()); |
80bfed90 | 244 | put_cpu(); |
1da177e4 LT |
245 | } |
246 | ||
053837fc | 247 | #ifdef CONFIG_NUMA |
c4028958 | 248 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
053837fc NP |
249 | { |
250 | lru_add_drain(); | |
251 | } | |
252 | ||
253 | /* | |
254 | * Returns 0 for success | |
255 | */ | |
256 | int lru_add_drain_all(void) | |
257 | { | |
c4028958 | 258 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
053837fc NP |
259 | } |
260 | ||
261 | #else | |
262 | ||
263 | /* | |
264 | * Returns 0 for success | |
265 | */ | |
266 | int lru_add_drain_all(void) | |
267 | { | |
268 | lru_add_drain(); | |
269 | return 0; | |
270 | } | |
271 | #endif | |
272 | ||
1da177e4 LT |
273 | /* |
274 | * Batched page_cache_release(). Decrement the reference count on all the | |
275 | * passed pages. If it fell to zero then remove the page from the LRU and | |
276 | * free it. | |
277 | * | |
278 | * Avoid taking zone->lru_lock if possible, but if it is taken, retain it | |
279 | * for the remainder of the operation. | |
280 | * | |
ab33dc09 FLVC |
281 | * The locking in this function is against shrink_inactive_list(): we recheck |
282 | * the page count inside the lock to see whether shrink_inactive_list() | |
283 | * grabbed the page via the LRU. If it did, give up: shrink_inactive_list() | |
284 | * will free it. | |
1da177e4 LT |
285 | */ |
286 | void release_pages(struct page **pages, int nr, int cold) | |
287 | { | |
288 | int i; | |
289 | struct pagevec pages_to_free; | |
290 | struct zone *zone = NULL; | |
902aaed0 | 291 | unsigned long uninitialized_var(flags); |
1da177e4 LT |
292 | |
293 | pagevec_init(&pages_to_free, cold); | |
294 | for (i = 0; i < nr; i++) { | |
295 | struct page *page = pages[i]; | |
1da177e4 | 296 | |
8519fb30 NP |
297 | if (unlikely(PageCompound(page))) { |
298 | if (zone) { | |
902aaed0 | 299 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
8519fb30 NP |
300 | zone = NULL; |
301 | } | |
302 | put_compound_page(page); | |
303 | continue; | |
304 | } | |
305 | ||
b5810039 | 306 | if (!put_page_testzero(page)) |
1da177e4 LT |
307 | continue; |
308 | ||
46453a6e NP |
309 | if (PageLRU(page)) { |
310 | struct zone *pagezone = page_zone(page); | |
311 | if (pagezone != zone) { | |
312 | if (zone) | |
902aaed0 HH |
313 | spin_unlock_irqrestore(&zone->lru_lock, |
314 | flags); | |
46453a6e | 315 | zone = pagezone; |
902aaed0 | 316 | spin_lock_irqsave(&zone->lru_lock, flags); |
46453a6e | 317 | } |
725d704e | 318 | VM_BUG_ON(!PageLRU(page)); |
67453911 | 319 | __ClearPageLRU(page); |
1da177e4 | 320 | del_page_from_lru(zone, page); |
46453a6e NP |
321 | } |
322 | ||
323 | if (!pagevec_add(&pages_to_free, page)) { | |
324 | if (zone) { | |
902aaed0 | 325 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
46453a6e | 326 | zone = NULL; |
1da177e4 | 327 | } |
46453a6e NP |
328 | __pagevec_free(&pages_to_free); |
329 | pagevec_reinit(&pages_to_free); | |
330 | } | |
1da177e4 LT |
331 | } |
332 | if (zone) | |
902aaed0 | 333 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
1da177e4 LT |
334 | |
335 | pagevec_free(&pages_to_free); | |
336 | } | |
337 | ||
338 | /* | |
339 | * The pages which we're about to release may be in the deferred lru-addition | |
340 | * queues. That would prevent them from really being freed right now. That's | |
341 | * OK from a correctness point of view but is inefficient - those pages may be | |
342 | * cache-warm and we want to give them back to the page allocator ASAP. | |
343 | * | |
344 | * So __pagevec_release() will drain those queues here. __pagevec_lru_add() | |
345 | * and __pagevec_lru_add_active() call release_pages() directly to avoid | |
346 | * mutual recursion. | |
347 | */ | |
348 | void __pagevec_release(struct pagevec *pvec) | |
349 | { | |
350 | lru_add_drain(); | |
351 | release_pages(pvec->pages, pagevec_count(pvec), pvec->cold); | |
352 | pagevec_reinit(pvec); | |
353 | } | |
354 | ||
7f285701 SF |
355 | EXPORT_SYMBOL(__pagevec_release); |
356 | ||
1da177e4 LT |
357 | /* |
358 | * pagevec_release() for pages which are known to not be on the LRU | |
359 | * | |
360 | * This function reinitialises the caller's pagevec. | |
361 | */ | |
362 | void __pagevec_release_nonlru(struct pagevec *pvec) | |
363 | { | |
364 | int i; | |
365 | struct pagevec pages_to_free; | |
366 | ||
367 | pagevec_init(&pages_to_free, pvec->cold); | |
1da177e4 LT |
368 | for (i = 0; i < pagevec_count(pvec); i++) { |
369 | struct page *page = pvec->pages[i]; | |
370 | ||
725d704e | 371 | VM_BUG_ON(PageLRU(page)); |
1da177e4 LT |
372 | if (put_page_testzero(page)) |
373 | pagevec_add(&pages_to_free, page); | |
374 | } | |
375 | pagevec_free(&pages_to_free); | |
376 | pagevec_reinit(pvec); | |
377 | } | |
378 | ||
379 | /* | |
380 | * Add the passed pages to the LRU, then drop the caller's refcount | |
381 | * on them. Reinitialises the caller's pagevec. | |
382 | */ | |
f04e9ebb | 383 | void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru) |
1da177e4 LT |
384 | { |
385 | int i; | |
386 | struct zone *zone = NULL; | |
387 | ||
388 | for (i = 0; i < pagevec_count(pvec); i++) { | |
389 | struct page *page = pvec->pages[i]; | |
390 | struct zone *pagezone = page_zone(page); | |
391 | ||
392 | if (pagezone != zone) { | |
393 | if (zone) | |
394 | spin_unlock_irq(&zone->lru_lock); | |
395 | zone = pagezone; | |
396 | spin_lock_irq(&zone->lru_lock); | |
397 | } | |
725d704e | 398 | VM_BUG_ON(PageLRU(page)); |
8d438f96 | 399 | SetPageLRU(page); |
f04e9ebb KM |
400 | if (is_active_lru(lru)) |
401 | SetPageActive(page); | |
402 | add_page_to_lru_list(zone, page, lru); | |
1da177e4 LT |
403 | } |
404 | if (zone) | |
405 | spin_unlock_irq(&zone->lru_lock); | |
406 | release_pages(pvec->pages, pvec->nr, pvec->cold); | |
407 | pagevec_reinit(pvec); | |
408 | } | |
409 | ||
f04e9ebb | 410 | EXPORT_SYMBOL(____pagevec_lru_add); |
1da177e4 LT |
411 | |
412 | /* | |
413 | * Try to drop buffers from the pages in a pagevec | |
414 | */ | |
415 | void pagevec_strip(struct pagevec *pvec) | |
416 | { | |
417 | int i; | |
418 | ||
419 | for (i = 0; i < pagevec_count(pvec); i++) { | |
420 | struct page *page = pvec->pages[i]; | |
421 | ||
529ae9aa | 422 | if (PagePrivate(page) && trylock_page(page)) { |
5b40dc78 CL |
423 | if (PagePrivate(page)) |
424 | try_to_release_page(page, 0); | |
1da177e4 LT |
425 | unlock_page(page); |
426 | } | |
427 | } | |
428 | } | |
429 | ||
68a22394 RR |
430 | /** |
431 | * pagevec_swap_free - try to free swap space from the pages in a pagevec | |
432 | * @pvec: pagevec with swapcache pages to free the swap space of | |
433 | * | |
434 | * The caller needs to hold an extra reference to each page and | |
435 | * not hold the page lock on the pages. This function uses a | |
436 | * trylock on the page lock so it may not always free the swap | |
437 | * space associated with a page. | |
438 | */ | |
439 | void pagevec_swap_free(struct pagevec *pvec) | |
440 | { | |
441 | int i; | |
442 | ||
443 | for (i = 0; i < pagevec_count(pvec); i++) { | |
444 | struct page *page = pvec->pages[i]; | |
445 | ||
446 | if (PageSwapCache(page) && trylock_page(page)) { | |
447 | if (PageSwapCache(page)) | |
448 | remove_exclusive_swap_page_ref(page); | |
449 | unlock_page(page); | |
450 | } | |
451 | } | |
452 | } | |
453 | ||
1da177e4 LT |
454 | /** |
455 | * pagevec_lookup - gang pagecache lookup | |
456 | * @pvec: Where the resulting pages are placed | |
457 | * @mapping: The address_space to search | |
458 | * @start: The starting page index | |
459 | * @nr_pages: The maximum number of pages | |
460 | * | |
461 | * pagevec_lookup() will search for and return a group of up to @nr_pages pages | |
462 | * in the mapping. The pages are placed in @pvec. pagevec_lookup() takes a | |
463 | * reference against the pages in @pvec. | |
464 | * | |
465 | * The search returns a group of mapping-contiguous pages with ascending | |
466 | * indexes. There may be holes in the indices due to not-present pages. | |
467 | * | |
468 | * pagevec_lookup() returns the number of pages which were found. | |
469 | */ | |
470 | unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, | |
471 | pgoff_t start, unsigned nr_pages) | |
472 | { | |
473 | pvec->nr = find_get_pages(mapping, start, nr_pages, pvec->pages); | |
474 | return pagevec_count(pvec); | |
475 | } | |
476 | ||
78539fdf CH |
477 | EXPORT_SYMBOL(pagevec_lookup); |
478 | ||
1da177e4 LT |
479 | unsigned pagevec_lookup_tag(struct pagevec *pvec, struct address_space *mapping, |
480 | pgoff_t *index, int tag, unsigned nr_pages) | |
481 | { | |
482 | pvec->nr = find_get_pages_tag(mapping, index, tag, | |
483 | nr_pages, pvec->pages); | |
484 | return pagevec_count(pvec); | |
485 | } | |
486 | ||
7f285701 | 487 | EXPORT_SYMBOL(pagevec_lookup_tag); |
1da177e4 LT |
488 | |
489 | #ifdef CONFIG_SMP | |
490 | /* | |
491 | * We tolerate a little inaccuracy to avoid ping-ponging the counter between | |
492 | * CPUs | |
493 | */ | |
494 | #define ACCT_THRESHOLD max(16, NR_CPUS * 2) | |
495 | ||
f84f9504 | 496 | static DEFINE_PER_CPU(long, committed_space); |
1da177e4 LT |
497 | |
498 | void vm_acct_memory(long pages) | |
499 | { | |
500 | long *local; | |
501 | ||
502 | preempt_disable(); | |
503 | local = &__get_cpu_var(committed_space); | |
504 | *local += pages; | |
505 | if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) { | |
80119ef5 | 506 | atomic_long_add(*local, &vm_committed_space); |
1da177e4 LT |
507 | *local = 0; |
508 | } | |
509 | preempt_enable(); | |
510 | } | |
1da177e4 LT |
511 | |
512 | #ifdef CONFIG_HOTPLUG_CPU | |
1da177e4 LT |
513 | |
514 | /* Drop the CPU's cached committed space back into the central pool. */ | |
515 | static int cpu_swap_callback(struct notifier_block *nfb, | |
516 | unsigned long action, | |
517 | void *hcpu) | |
518 | { | |
519 | long *committed; | |
520 | ||
521 | committed = &per_cpu(committed_space, (long)hcpu); | |
8bb78442 | 522 | if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { |
80119ef5 | 523 | atomic_long_add(*committed, &vm_committed_space); |
1da177e4 | 524 | *committed = 0; |
902aaed0 | 525 | drain_cpu_pagevecs((long)hcpu); |
1da177e4 LT |
526 | } |
527 | return NOTIFY_OK; | |
528 | } | |
529 | #endif /* CONFIG_HOTPLUG_CPU */ | |
530 | #endif /* CONFIG_SMP */ | |
531 | ||
1da177e4 LT |
532 | /* |
533 | * Perform any setup for the swap system | |
534 | */ | |
535 | void __init swap_setup(void) | |
536 | { | |
537 | unsigned long megs = num_physpages >> (20 - PAGE_SHIFT); | |
538 | ||
e0bf68dd PZ |
539 | #ifdef CONFIG_SWAP |
540 | bdi_init(swapper_space.backing_dev_info); | |
541 | #endif | |
542 | ||
1da177e4 LT |
543 | /* Use a smaller cluster for small-memory machines */ |
544 | if (megs < 16) | |
545 | page_cluster = 2; | |
546 | else | |
547 | page_cluster = 3; | |
548 | /* | |
549 | * Right now other parts of the system means that we | |
550 | * _really_ don't want to cluster much more | |
551 | */ | |
02316067 | 552 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 553 | hotcpu_notifier(cpu_swap_callback, 0); |
02316067 | 554 | #endif |
1da177e4 | 555 | } |