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Commit | Line | Data |
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748446bb MG |
1 | /* |
2 | * linux/mm/compaction.c | |
3 | * | |
4 | * Memory compaction for the reduction of external fragmentation. Note that | |
5 | * this heavily depends upon page migration to do all the real heavy | |
6 | * lifting | |
7 | * | |
8 | * Copyright IBM Corp. 2007-2010 Mel Gorman <mel@csn.ul.ie> | |
9 | */ | |
10 | #include <linux/swap.h> | |
11 | #include <linux/migrate.h> | |
12 | #include <linux/compaction.h> | |
13 | #include <linux/mm_inline.h> | |
14 | #include <linux/backing-dev.h> | |
76ab0f53 | 15 | #include <linux/sysctl.h> |
ed4a6d7f | 16 | #include <linux/sysfs.h> |
748446bb MG |
17 | #include "internal.h" |
18 | ||
ff9543fd MN |
19 | #if defined CONFIG_COMPACTION || defined CONFIG_CMA |
20 | ||
b7aba698 MG |
21 | #define CREATE_TRACE_POINTS |
22 | #include <trace/events/compaction.h> | |
23 | ||
748446bb MG |
24 | static unsigned long release_freepages(struct list_head *freelist) |
25 | { | |
26 | struct page *page, *next; | |
27 | unsigned long count = 0; | |
28 | ||
29 | list_for_each_entry_safe(page, next, freelist, lru) { | |
30 | list_del(&page->lru); | |
31 | __free_page(page); | |
32 | count++; | |
33 | } | |
34 | ||
35 | return count; | |
36 | } | |
37 | ||
ff9543fd MN |
38 | static void map_pages(struct list_head *list) |
39 | { | |
40 | struct page *page; | |
41 | ||
42 | list_for_each_entry(page, list, lru) { | |
43 | arch_alloc_page(page, 0); | |
44 | kernel_map_pages(page, 1, 1); | |
45 | } | |
46 | } | |
47 | ||
47118af0 MN |
48 | static inline bool migrate_async_suitable(int migratetype) |
49 | { | |
50 | return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE; | |
51 | } | |
52 | ||
c67fe375 MG |
53 | /* |
54 | * Compaction requires the taking of some coarse locks that are potentially | |
55 | * very heavily contended. Check if the process needs to be scheduled or | |
56 | * if the lock is contended. For async compaction, back out in the event | |
57 | * if contention is severe. For sync compaction, schedule. | |
58 | * | |
59 | * Returns true if the lock is held. | |
60 | * Returns false if the lock is released and compaction should abort | |
61 | */ | |
62 | static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, | |
63 | bool locked, struct compact_control *cc) | |
64 | { | |
65 | if (need_resched() || spin_is_contended(lock)) { | |
66 | if (locked) { | |
67 | spin_unlock_irqrestore(lock, *flags); | |
68 | locked = false; | |
69 | } | |
70 | ||
71 | /* async aborts if taking too long or contended */ | |
72 | if (!cc->sync) { | |
73 | if (cc->contended) | |
74 | *cc->contended = true; | |
75 | return false; | |
76 | } | |
77 | ||
78 | cond_resched(); | |
79 | if (fatal_signal_pending(current)) | |
80 | return false; | |
81 | } | |
82 | ||
83 | if (!locked) | |
84 | spin_lock_irqsave(lock, *flags); | |
85 | return true; | |
86 | } | |
87 | ||
88 | static inline bool compact_trylock_irqsave(spinlock_t *lock, | |
89 | unsigned long *flags, struct compact_control *cc) | |
90 | { | |
91 | return compact_checklock_irqsave(lock, flags, false, cc); | |
92 | } | |
93 | ||
1fb3f8ca MG |
94 | static void compact_capture_page(struct compact_control *cc) |
95 | { | |
96 | unsigned long flags; | |
97 | int mtype, mtype_low, mtype_high; | |
98 | ||
99 | if (!cc->page || *cc->page) | |
100 | return; | |
101 | ||
102 | /* | |
103 | * For MIGRATE_MOVABLE allocations we capture a suitable page ASAP | |
104 | * regardless of the migratetype of the freelist is is captured from. | |
105 | * This is fine because the order for a high-order MIGRATE_MOVABLE | |
106 | * allocation is typically at least a pageblock size and overall | |
107 | * fragmentation is not impaired. Other allocation types must | |
108 | * capture pages from their own migratelist because otherwise they | |
109 | * could pollute other pageblocks like MIGRATE_MOVABLE with | |
110 | * difficult to move pages and making fragmentation worse overall. | |
111 | */ | |
112 | if (cc->migratetype == MIGRATE_MOVABLE) { | |
113 | mtype_low = 0; | |
114 | mtype_high = MIGRATE_PCPTYPES; | |
115 | } else { | |
116 | mtype_low = cc->migratetype; | |
117 | mtype_high = cc->migratetype + 1; | |
118 | } | |
119 | ||
120 | /* Speculatively examine the free lists without zone lock */ | |
121 | for (mtype = mtype_low; mtype < mtype_high; mtype++) { | |
122 | int order; | |
123 | for (order = cc->order; order < MAX_ORDER; order++) { | |
124 | struct page *page; | |
125 | struct free_area *area; | |
126 | area = &(cc->zone->free_area[order]); | |
127 | if (list_empty(&area->free_list[mtype])) | |
128 | continue; | |
129 | ||
130 | /* Take the lock and attempt capture of the page */ | |
131 | if (!compact_trylock_irqsave(&cc->zone->lock, &flags, cc)) | |
132 | return; | |
133 | if (!list_empty(&area->free_list[mtype])) { | |
134 | page = list_entry(area->free_list[mtype].next, | |
135 | struct page, lru); | |
136 | if (capture_free_page(page, cc->order, mtype)) { | |
137 | spin_unlock_irqrestore(&cc->zone->lock, | |
138 | flags); | |
139 | *cc->page = page; | |
140 | return; | |
141 | } | |
142 | } | |
143 | spin_unlock_irqrestore(&cc->zone->lock, flags); | |
144 | } | |
145 | } | |
146 | } | |
147 | ||
85aa125f MN |
148 | /* |
149 | * Isolate free pages onto a private freelist. Caller must hold zone->lock. | |
150 | * If @strict is true, will abort returning 0 on any invalid PFNs or non-free | |
151 | * pages inside of the pageblock (even though it may still end up isolating | |
152 | * some pages). | |
153 | */ | |
154 | static unsigned long isolate_freepages_block(unsigned long blockpfn, | |
155 | unsigned long end_pfn, | |
156 | struct list_head *freelist, | |
157 | bool strict) | |
748446bb | 158 | { |
b7aba698 | 159 | int nr_scanned = 0, total_isolated = 0; |
748446bb MG |
160 | struct page *cursor; |
161 | ||
748446bb MG |
162 | cursor = pfn_to_page(blockpfn); |
163 | ||
164 | /* Isolate free pages. This assumes the block is valid */ | |
165 | for (; blockpfn < end_pfn; blockpfn++, cursor++) { | |
166 | int isolated, i; | |
167 | struct page *page = cursor; | |
168 | ||
85aa125f MN |
169 | if (!pfn_valid_within(blockpfn)) { |
170 | if (strict) | |
171 | return 0; | |
748446bb | 172 | continue; |
85aa125f | 173 | } |
b7aba698 | 174 | nr_scanned++; |
748446bb | 175 | |
85aa125f MN |
176 | if (!PageBuddy(page)) { |
177 | if (strict) | |
178 | return 0; | |
748446bb | 179 | continue; |
85aa125f | 180 | } |
748446bb MG |
181 | |
182 | /* Found a free page, break it into order-0 pages */ | |
183 | isolated = split_free_page(page); | |
85aa125f MN |
184 | if (!isolated && strict) |
185 | return 0; | |
748446bb MG |
186 | total_isolated += isolated; |
187 | for (i = 0; i < isolated; i++) { | |
188 | list_add(&page->lru, freelist); | |
189 | page++; | |
190 | } | |
191 | ||
192 | /* If a page was split, advance to the end of it */ | |
193 | if (isolated) { | |
194 | blockpfn += isolated - 1; | |
195 | cursor += isolated - 1; | |
196 | } | |
197 | } | |
198 | ||
b7aba698 | 199 | trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated); |
748446bb MG |
200 | return total_isolated; |
201 | } | |
202 | ||
85aa125f MN |
203 | /** |
204 | * isolate_freepages_range() - isolate free pages. | |
205 | * @start_pfn: The first PFN to start isolating. | |
206 | * @end_pfn: The one-past-last PFN. | |
207 | * | |
208 | * Non-free pages, invalid PFNs, or zone boundaries within the | |
209 | * [start_pfn, end_pfn) range are considered errors, cause function to | |
210 | * undo its actions and return zero. | |
211 | * | |
212 | * Otherwise, function returns one-past-the-last PFN of isolated page | |
213 | * (which may be greater then end_pfn if end fell in a middle of | |
214 | * a free page). | |
215 | */ | |
ff9543fd | 216 | unsigned long |
85aa125f MN |
217 | isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn) |
218 | { | |
219 | unsigned long isolated, pfn, block_end_pfn, flags; | |
220 | struct zone *zone = NULL; | |
221 | LIST_HEAD(freelist); | |
222 | ||
223 | if (pfn_valid(start_pfn)) | |
224 | zone = page_zone(pfn_to_page(start_pfn)); | |
225 | ||
226 | for (pfn = start_pfn; pfn < end_pfn; pfn += isolated) { | |
227 | if (!pfn_valid(pfn) || zone != page_zone(pfn_to_page(pfn))) | |
228 | break; | |
229 | ||
230 | /* | |
231 | * On subsequent iterations ALIGN() is actually not needed, | |
232 | * but we keep it that we not to complicate the code. | |
233 | */ | |
234 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
235 | block_end_pfn = min(block_end_pfn, end_pfn); | |
236 | ||
237 | spin_lock_irqsave(&zone->lock, flags); | |
238 | isolated = isolate_freepages_block(pfn, block_end_pfn, | |
239 | &freelist, true); | |
240 | spin_unlock_irqrestore(&zone->lock, flags); | |
241 | ||
242 | /* | |
243 | * In strict mode, isolate_freepages_block() returns 0 if | |
244 | * there are any holes in the block (ie. invalid PFNs or | |
245 | * non-free pages). | |
246 | */ | |
247 | if (!isolated) | |
248 | break; | |
249 | ||
250 | /* | |
251 | * If we managed to isolate pages, it is always (1 << n) * | |
252 | * pageblock_nr_pages for some non-negative n. (Max order | |
253 | * page may span two pageblocks). | |
254 | */ | |
255 | } | |
256 | ||
257 | /* split_free_page does not map the pages */ | |
258 | map_pages(&freelist); | |
259 | ||
260 | if (pfn < end_pfn) { | |
261 | /* Loop terminated early, cleanup. */ | |
262 | release_freepages(&freelist); | |
263 | return 0; | |
264 | } | |
265 | ||
266 | /* We don't use freelists for anything. */ | |
267 | return pfn; | |
268 | } | |
269 | ||
748446bb | 270 | /* Update the number of anon and file isolated pages in the zone */ |
c67fe375 | 271 | static void acct_isolated(struct zone *zone, bool locked, struct compact_control *cc) |
748446bb MG |
272 | { |
273 | struct page *page; | |
b9e84ac1 | 274 | unsigned int count[2] = { 0, }; |
748446bb | 275 | |
b9e84ac1 MK |
276 | list_for_each_entry(page, &cc->migratepages, lru) |
277 | count[!!page_is_file_cache(page)]++; | |
748446bb | 278 | |
c67fe375 MG |
279 | /* If locked we can use the interrupt unsafe versions */ |
280 | if (locked) { | |
281 | __mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]); | |
282 | __mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); | |
283 | } else { | |
284 | mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]); | |
285 | mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]); | |
286 | } | |
748446bb MG |
287 | } |
288 | ||
289 | /* Similar to reclaim, but different enough that they don't share logic */ | |
290 | static bool too_many_isolated(struct zone *zone) | |
291 | { | |
bc693045 | 292 | unsigned long active, inactive, isolated; |
748446bb MG |
293 | |
294 | inactive = zone_page_state(zone, NR_INACTIVE_FILE) + | |
295 | zone_page_state(zone, NR_INACTIVE_ANON); | |
bc693045 MK |
296 | active = zone_page_state(zone, NR_ACTIVE_FILE) + |
297 | zone_page_state(zone, NR_ACTIVE_ANON); | |
748446bb MG |
298 | isolated = zone_page_state(zone, NR_ISOLATED_FILE) + |
299 | zone_page_state(zone, NR_ISOLATED_ANON); | |
300 | ||
bc693045 | 301 | return isolated > (inactive + active) / 2; |
748446bb MG |
302 | } |
303 | ||
2fe86e00 MN |
304 | /** |
305 | * isolate_migratepages_range() - isolate all migrate-able pages in range. | |
306 | * @zone: Zone pages are in. | |
307 | * @cc: Compaction control structure. | |
308 | * @low_pfn: The first PFN of the range. | |
309 | * @end_pfn: The one-past-the-last PFN of the range. | |
310 | * | |
311 | * Isolate all pages that can be migrated from the range specified by | |
312 | * [low_pfn, end_pfn). Returns zero if there is a fatal signal | |
313 | * pending), otherwise PFN of the first page that was not scanned | |
314 | * (which may be both less, equal to or more then end_pfn). | |
315 | * | |
316 | * Assumes that cc->migratepages is empty and cc->nr_migratepages is | |
317 | * zero. | |
318 | * | |
319 | * Apart from cc->migratepages and cc->nr_migratetypes this function | |
320 | * does not modify any cc's fields, in particular it does not modify | |
321 | * (or read for that matter) cc->migrate_pfn. | |
748446bb | 322 | */ |
ff9543fd | 323 | unsigned long |
2fe86e00 MN |
324 | isolate_migratepages_range(struct zone *zone, struct compact_control *cc, |
325 | unsigned long low_pfn, unsigned long end_pfn) | |
748446bb | 326 | { |
9927af74 | 327 | unsigned long last_pageblock_nr = 0, pageblock_nr; |
b7aba698 | 328 | unsigned long nr_scanned = 0, nr_isolated = 0; |
748446bb | 329 | struct list_head *migratelist = &cc->migratepages; |
f3fd4a61 | 330 | isolate_mode_t mode = 0; |
fa9add64 | 331 | struct lruvec *lruvec; |
c67fe375 MG |
332 | unsigned long flags; |
333 | bool locked; | |
748446bb | 334 | |
748446bb MG |
335 | /* |
336 | * Ensure that there are not too many pages isolated from the LRU | |
337 | * list by either parallel reclaimers or compaction. If there are, | |
338 | * delay for some time until fewer pages are isolated | |
339 | */ | |
340 | while (unlikely(too_many_isolated(zone))) { | |
f9e35b3b | 341 | /* async migration should just abort */ |
68e3e926 | 342 | if (!cc->sync) |
2fe86e00 | 343 | return 0; |
f9e35b3b | 344 | |
748446bb MG |
345 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
346 | ||
347 | if (fatal_signal_pending(current)) | |
2fe86e00 | 348 | return 0; |
748446bb MG |
349 | } |
350 | ||
351 | /* Time to isolate some pages for migration */ | |
b2eef8c0 | 352 | cond_resched(); |
c67fe375 MG |
353 | spin_lock_irqsave(&zone->lru_lock, flags); |
354 | locked = true; | |
748446bb MG |
355 | for (; low_pfn < end_pfn; low_pfn++) { |
356 | struct page *page; | |
b2eef8c0 AA |
357 | |
358 | /* give a chance to irqs before checking need_resched() */ | |
359 | if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) { | |
c67fe375 | 360 | spin_unlock_irqrestore(&zone->lru_lock, flags); |
b2eef8c0 AA |
361 | locked = false; |
362 | } | |
c67fe375 MG |
363 | |
364 | /* Check if it is ok to still hold the lock */ | |
365 | locked = compact_checklock_irqsave(&zone->lru_lock, &flags, | |
366 | locked, cc); | |
367 | if (!locked) | |
368 | break; | |
b2eef8c0 | 369 | |
0bf380bc MG |
370 | /* |
371 | * migrate_pfn does not necessarily start aligned to a | |
372 | * pageblock. Ensure that pfn_valid is called when moving | |
373 | * into a new MAX_ORDER_NR_PAGES range in case of large | |
374 | * memory holes within the zone | |
375 | */ | |
376 | if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) { | |
377 | if (!pfn_valid(low_pfn)) { | |
378 | low_pfn += MAX_ORDER_NR_PAGES - 1; | |
379 | continue; | |
380 | } | |
381 | } | |
382 | ||
748446bb MG |
383 | if (!pfn_valid_within(low_pfn)) |
384 | continue; | |
b7aba698 | 385 | nr_scanned++; |
748446bb | 386 | |
dc908600 MG |
387 | /* |
388 | * Get the page and ensure the page is within the same zone. | |
389 | * See the comment in isolate_freepages about overlapping | |
390 | * nodes. It is deliberate that the new zone lock is not taken | |
391 | * as memory compaction should not move pages between nodes. | |
392 | */ | |
748446bb | 393 | page = pfn_to_page(low_pfn); |
dc908600 MG |
394 | if (page_zone(page) != zone) |
395 | continue; | |
396 | ||
397 | /* Skip if free */ | |
748446bb MG |
398 | if (PageBuddy(page)) |
399 | continue; | |
400 | ||
9927af74 MG |
401 | /* |
402 | * For async migration, also only scan in MOVABLE blocks. Async | |
403 | * migration is optimistic to see if the minimum amount of work | |
404 | * satisfies the allocation | |
405 | */ | |
406 | pageblock_nr = low_pfn >> pageblock_order; | |
68e3e926 | 407 | if (!cc->sync && last_pageblock_nr != pageblock_nr && |
47118af0 | 408 | !migrate_async_suitable(get_pageblock_migratetype(page))) { |
9927af74 MG |
409 | low_pfn += pageblock_nr_pages; |
410 | low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1; | |
411 | last_pageblock_nr = pageblock_nr; | |
412 | continue; | |
413 | } | |
414 | ||
bc835011 AA |
415 | if (!PageLRU(page)) |
416 | continue; | |
417 | ||
418 | /* | |
419 | * PageLRU is set, and lru_lock excludes isolation, | |
420 | * splitting and collapsing (collapsing has already | |
421 | * happened if PageLRU is set). | |
422 | */ | |
423 | if (PageTransHuge(page)) { | |
424 | low_pfn += (1 << compound_order(page)) - 1; | |
425 | continue; | |
426 | } | |
427 | ||
68e3e926 | 428 | if (!cc->sync) |
c8244935 MG |
429 | mode |= ISOLATE_ASYNC_MIGRATE; |
430 | ||
fa9add64 HD |
431 | lruvec = mem_cgroup_page_lruvec(page, zone); |
432 | ||
748446bb | 433 | /* Try isolate the page */ |
f3fd4a61 | 434 | if (__isolate_lru_page(page, mode) != 0) |
748446bb MG |
435 | continue; |
436 | ||
bc835011 AA |
437 | VM_BUG_ON(PageTransCompound(page)); |
438 | ||
748446bb | 439 | /* Successfully isolated */ |
fa9add64 | 440 | del_page_from_lru_list(page, lruvec, page_lru(page)); |
748446bb | 441 | list_add(&page->lru, migratelist); |
748446bb | 442 | cc->nr_migratepages++; |
b7aba698 | 443 | nr_isolated++; |
748446bb MG |
444 | |
445 | /* Avoid isolating too much */ | |
31b8384a HD |
446 | if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) { |
447 | ++low_pfn; | |
748446bb | 448 | break; |
31b8384a | 449 | } |
748446bb MG |
450 | } |
451 | ||
c67fe375 | 452 | acct_isolated(zone, locked, cc); |
748446bb | 453 | |
c67fe375 MG |
454 | if (locked) |
455 | spin_unlock_irqrestore(&zone->lru_lock, flags); | |
748446bb | 456 | |
b7aba698 MG |
457 | trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated); |
458 | ||
2fe86e00 MN |
459 | return low_pfn; |
460 | } | |
461 | ||
ff9543fd MN |
462 | #endif /* CONFIG_COMPACTION || CONFIG_CMA */ |
463 | #ifdef CONFIG_COMPACTION | |
464 | ||
68e3e926 LT |
465 | /* Returns true if the page is within a block suitable for migration to */ |
466 | static bool suitable_migration_target(struct page *page) | |
ff9543fd MN |
467 | { |
468 | ||
469 | int migratetype = get_pageblock_migratetype(page); | |
470 | ||
471 | /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */ | |
472 | if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE) | |
68e3e926 | 473 | return false; |
ff9543fd MN |
474 | |
475 | /* If the page is a large free page, then allow migration */ | |
476 | if (PageBuddy(page) && page_order(page) >= pageblock_order) | |
68e3e926 | 477 | return true; |
ff9543fd | 478 | |
47118af0 | 479 | /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */ |
68e3e926 LT |
480 | if (migrate_async_suitable(migratetype)) |
481 | return true; | |
ff9543fd MN |
482 | |
483 | /* Otherwise skip the block */ | |
68e3e926 | 484 | return false; |
ff9543fd MN |
485 | } |
486 | ||
de74f1cc MG |
487 | /* |
488 | * Returns the start pfn of the last page block in a zone. This is the starting | |
489 | * point for full compaction of a zone. Compaction searches for free pages from | |
490 | * the end of each zone, while isolate_freepages_block scans forward inside each | |
491 | * page block. | |
492 | */ | |
493 | static unsigned long start_free_pfn(struct zone *zone) | |
494 | { | |
495 | unsigned long free_pfn; | |
496 | free_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
497 | free_pfn &= ~(pageblock_nr_pages-1); | |
498 | return free_pfn; | |
499 | } | |
500 | ||
2fe86e00 | 501 | /* |
ff9543fd MN |
502 | * Based on information in the current compact_control, find blocks |
503 | * suitable for isolating free pages from and then isolate them. | |
2fe86e00 | 504 | */ |
ff9543fd MN |
505 | static void isolate_freepages(struct zone *zone, |
506 | struct compact_control *cc) | |
2fe86e00 | 507 | { |
ff9543fd MN |
508 | struct page *page; |
509 | unsigned long high_pfn, low_pfn, pfn, zone_end_pfn, end_pfn; | |
510 | unsigned long flags; | |
511 | int nr_freepages = cc->nr_freepages; | |
512 | struct list_head *freelist = &cc->freepages; | |
2fe86e00 | 513 | |
ff9543fd MN |
514 | /* |
515 | * Initialise the free scanner. The starting point is where we last | |
516 | * scanned from (or the end of the zone if starting). The low point | |
517 | * is the end of the pageblock the migration scanner is using. | |
518 | */ | |
519 | pfn = cc->free_pfn; | |
520 | low_pfn = cc->migrate_pfn + pageblock_nr_pages; | |
2fe86e00 | 521 | |
ff9543fd MN |
522 | /* |
523 | * Take care that if the migration scanner is at the end of the zone | |
524 | * that the free scanner does not accidentally move to the next zone | |
525 | * in the next isolation cycle. | |
526 | */ | |
527 | high_pfn = min(low_pfn, pfn); | |
2fe86e00 | 528 | |
ff9543fd | 529 | zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; |
2fe86e00 | 530 | |
ff9543fd MN |
531 | /* |
532 | * Isolate free pages until enough are available to migrate the | |
533 | * pages on cc->migratepages. We stop searching if the migrate | |
534 | * and free page scanners meet or enough free pages are isolated. | |
535 | */ | |
536 | for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; | |
537 | pfn -= pageblock_nr_pages) { | |
538 | unsigned long isolated; | |
2fe86e00 | 539 | |
ff9543fd MN |
540 | if (!pfn_valid(pfn)) |
541 | continue; | |
2fe86e00 | 542 | |
ff9543fd MN |
543 | /* |
544 | * Check for overlapping nodes/zones. It's possible on some | |
545 | * configurations to have a setup like | |
546 | * node0 node1 node0 | |
547 | * i.e. it's possible that all pages within a zones range of | |
548 | * pages do not belong to a single zone. | |
549 | */ | |
550 | page = pfn_to_page(pfn); | |
551 | if (page_zone(page) != zone) | |
552 | continue; | |
553 | ||
554 | /* Check the block is suitable for migration */ | |
68e3e926 | 555 | if (!suitable_migration_target(page)) |
ff9543fd | 556 | continue; |
68e3e926 | 557 | |
ff9543fd MN |
558 | /* |
559 | * Found a block suitable for isolating free pages from. Now | |
560 | * we disabled interrupts, double check things are ok and | |
561 | * isolate the pages. This is to minimise the time IRQs | |
562 | * are disabled | |
563 | */ | |
564 | isolated = 0; | |
c67fe375 MG |
565 | |
566 | /* | |
567 | * The zone lock must be held to isolate freepages. This | |
568 | * unfortunately this is a very coarse lock and can be | |
569 | * heavily contended if there are parallel allocations | |
570 | * or parallel compactions. For async compaction do not | |
571 | * spin on the lock | |
572 | */ | |
573 | if (!compact_trylock_irqsave(&zone->lock, &flags, cc)) | |
574 | break; | |
68e3e926 | 575 | if (suitable_migration_target(page)) { |
ff9543fd MN |
576 | end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn); |
577 | isolated = isolate_freepages_block(pfn, end_pfn, | |
578 | freelist, false); | |
579 | nr_freepages += isolated; | |
68e3e926 | 580 | } |
ff9543fd MN |
581 | spin_unlock_irqrestore(&zone->lock, flags); |
582 | ||
583 | /* | |
584 | * Record the highest PFN we isolated pages from. When next | |
585 | * looking for free pages, the search will restart here as | |
586 | * page migration may have returned some pages to the allocator | |
587 | */ | |
7db8889a | 588 | if (isolated) { |
ff9543fd | 589 | high_pfn = max(high_pfn, pfn); |
de74f1cc MG |
590 | |
591 | /* | |
592 | * If the free scanner has wrapped, update | |
593 | * compact_cached_free_pfn to point to the highest | |
594 | * pageblock with free pages. This reduces excessive | |
595 | * scanning of full pageblocks near the end of the | |
596 | * zone | |
597 | */ | |
598 | if (cc->order > 0 && cc->wrapped) | |
7db8889a RR |
599 | zone->compact_cached_free_pfn = high_pfn; |
600 | } | |
ff9543fd MN |
601 | } |
602 | ||
603 | /* split_free_page does not map the pages */ | |
604 | map_pages(freelist); | |
605 | ||
606 | cc->free_pfn = high_pfn; | |
607 | cc->nr_freepages = nr_freepages; | |
de74f1cc MG |
608 | |
609 | /* If compact_cached_free_pfn is reset then set it now */ | |
610 | if (cc->order > 0 && !cc->wrapped && | |
611 | zone->compact_cached_free_pfn == start_free_pfn(zone)) | |
612 | zone->compact_cached_free_pfn = high_pfn; | |
748446bb MG |
613 | } |
614 | ||
615 | /* | |
616 | * This is a migrate-callback that "allocates" freepages by taking pages | |
617 | * from the isolated freelists in the block we are migrating to. | |
618 | */ | |
619 | static struct page *compaction_alloc(struct page *migratepage, | |
620 | unsigned long data, | |
621 | int **result) | |
622 | { | |
623 | struct compact_control *cc = (struct compact_control *)data; | |
624 | struct page *freepage; | |
625 | ||
626 | /* Isolate free pages if necessary */ | |
627 | if (list_empty(&cc->freepages)) { | |
628 | isolate_freepages(cc->zone, cc); | |
629 | ||
630 | if (list_empty(&cc->freepages)) | |
631 | return NULL; | |
632 | } | |
633 | ||
634 | freepage = list_entry(cc->freepages.next, struct page, lru); | |
635 | list_del(&freepage->lru); | |
636 | cc->nr_freepages--; | |
637 | ||
638 | return freepage; | |
639 | } | |
640 | ||
641 | /* | |
642 | * We cannot control nr_migratepages and nr_freepages fully when migration is | |
643 | * running as migrate_pages() has no knowledge of compact_control. When | |
644 | * migration is complete, we count the number of pages on the lists by hand. | |
645 | */ | |
646 | static void update_nr_listpages(struct compact_control *cc) | |
647 | { | |
648 | int nr_migratepages = 0; | |
649 | int nr_freepages = 0; | |
650 | struct page *page; | |
651 | ||
652 | list_for_each_entry(page, &cc->migratepages, lru) | |
653 | nr_migratepages++; | |
654 | list_for_each_entry(page, &cc->freepages, lru) | |
655 | nr_freepages++; | |
656 | ||
657 | cc->nr_migratepages = nr_migratepages; | |
658 | cc->nr_freepages = nr_freepages; | |
659 | } | |
660 | ||
ff9543fd MN |
661 | /* possible outcome of isolate_migratepages */ |
662 | typedef enum { | |
663 | ISOLATE_ABORT, /* Abort compaction now */ | |
664 | ISOLATE_NONE, /* No pages isolated, continue scanning */ | |
665 | ISOLATE_SUCCESS, /* Pages isolated, migrate */ | |
666 | } isolate_migrate_t; | |
667 | ||
668 | /* | |
669 | * Isolate all pages that can be migrated from the block pointed to by | |
670 | * the migrate scanner within compact_control. | |
671 | */ | |
672 | static isolate_migrate_t isolate_migratepages(struct zone *zone, | |
673 | struct compact_control *cc) | |
674 | { | |
675 | unsigned long low_pfn, end_pfn; | |
676 | ||
677 | /* Do not scan outside zone boundaries */ | |
678 | low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn); | |
679 | ||
680 | /* Only scan within a pageblock boundary */ | |
681 | end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages); | |
682 | ||
683 | /* Do not cross the free scanner or scan within a memory hole */ | |
684 | if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) { | |
685 | cc->migrate_pfn = end_pfn; | |
686 | return ISOLATE_NONE; | |
687 | } | |
688 | ||
689 | /* Perform the isolation */ | |
690 | low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn); | |
691 | if (!low_pfn) | |
692 | return ISOLATE_ABORT; | |
693 | ||
694 | cc->migrate_pfn = low_pfn; | |
695 | ||
696 | return ISOLATE_SUCCESS; | |
697 | } | |
698 | ||
748446bb | 699 | static int compact_finished(struct zone *zone, |
5a03b051 | 700 | struct compact_control *cc) |
748446bb | 701 | { |
5a03b051 | 702 | unsigned long watermark; |
56de7263 | 703 | |
748446bb MG |
704 | if (fatal_signal_pending(current)) |
705 | return COMPACT_PARTIAL; | |
706 | ||
7db8889a RR |
707 | /* |
708 | * A full (order == -1) compaction run starts at the beginning and | |
709 | * end of a zone; it completes when the migrate and free scanner meet. | |
710 | * A partial (order > 0) compaction can start with the free scanner | |
711 | * at a random point in the zone, and may have to restart. | |
712 | */ | |
713 | if (cc->free_pfn <= cc->migrate_pfn) { | |
714 | if (cc->order > 0 && !cc->wrapped) { | |
715 | /* We started partway through; restart at the end. */ | |
716 | unsigned long free_pfn = start_free_pfn(zone); | |
717 | zone->compact_cached_free_pfn = free_pfn; | |
718 | cc->free_pfn = free_pfn; | |
719 | cc->wrapped = 1; | |
720 | return COMPACT_CONTINUE; | |
721 | } | |
722 | return COMPACT_COMPLETE; | |
723 | } | |
724 | ||
725 | /* We wrapped around and ended up where we started. */ | |
726 | if (cc->wrapped && cc->free_pfn <= cc->start_free_pfn) | |
748446bb MG |
727 | return COMPACT_COMPLETE; |
728 | ||
82478fb7 JW |
729 | /* |
730 | * order == -1 is expected when compacting via | |
731 | * /proc/sys/vm/compact_memory | |
732 | */ | |
56de7263 MG |
733 | if (cc->order == -1) |
734 | return COMPACT_CONTINUE; | |
735 | ||
3957c776 MH |
736 | /* Compaction run is not finished if the watermark is not met */ |
737 | watermark = low_wmark_pages(zone); | |
738 | watermark += (1 << cc->order); | |
739 | ||
740 | if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0)) | |
741 | return COMPACT_CONTINUE; | |
742 | ||
56de7263 | 743 | /* Direct compactor: Is a suitable page free? */ |
1fb3f8ca MG |
744 | if (cc->page) { |
745 | /* Was a suitable page captured? */ | |
746 | if (*cc->page) | |
56de7263 | 747 | return COMPACT_PARTIAL; |
1fb3f8ca MG |
748 | } else { |
749 | unsigned int order; | |
750 | for (order = cc->order; order < MAX_ORDER; order++) { | |
751 | struct free_area *area = &zone->free_area[cc->order]; | |
752 | /* Job done if page is free of the right migratetype */ | |
753 | if (!list_empty(&area->free_list[cc->migratetype])) | |
754 | return COMPACT_PARTIAL; | |
755 | ||
756 | /* Job done if allocation would set block type */ | |
757 | if (cc->order >= pageblock_order && area->nr_free) | |
758 | return COMPACT_PARTIAL; | |
759 | } | |
56de7263 MG |
760 | } |
761 | ||
748446bb MG |
762 | return COMPACT_CONTINUE; |
763 | } | |
764 | ||
3e7d3449 MG |
765 | /* |
766 | * compaction_suitable: Is this suitable to run compaction on this zone now? | |
767 | * Returns | |
768 | * COMPACT_SKIPPED - If there are too few free pages for compaction | |
769 | * COMPACT_PARTIAL - If the allocation would succeed without compaction | |
770 | * COMPACT_CONTINUE - If compaction should run now | |
771 | */ | |
772 | unsigned long compaction_suitable(struct zone *zone, int order) | |
773 | { | |
774 | int fragindex; | |
775 | unsigned long watermark; | |
776 | ||
3957c776 MH |
777 | /* |
778 | * order == -1 is expected when compacting via | |
779 | * /proc/sys/vm/compact_memory | |
780 | */ | |
781 | if (order == -1) | |
782 | return COMPACT_CONTINUE; | |
783 | ||
3e7d3449 MG |
784 | /* |
785 | * Watermarks for order-0 must be met for compaction. Note the 2UL. | |
786 | * This is because during migration, copies of pages need to be | |
787 | * allocated and for a short time, the footprint is higher | |
788 | */ | |
789 | watermark = low_wmark_pages(zone) + (2UL << order); | |
790 | if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) | |
791 | return COMPACT_SKIPPED; | |
792 | ||
793 | /* | |
794 | * fragmentation index determines if allocation failures are due to | |
795 | * low memory or external fragmentation | |
796 | * | |
a582a738 SL |
797 | * index of -1000 implies allocations might succeed depending on |
798 | * watermarks | |
3e7d3449 MG |
799 | * index towards 0 implies failure is due to lack of memory |
800 | * index towards 1000 implies failure is due to fragmentation | |
801 | * | |
802 | * Only compact if a failure would be due to fragmentation. | |
803 | */ | |
804 | fragindex = fragmentation_index(zone, order); | |
805 | if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold) | |
806 | return COMPACT_SKIPPED; | |
807 | ||
a582a738 SL |
808 | if (fragindex == -1000 && zone_watermark_ok(zone, order, watermark, |
809 | 0, 0)) | |
3e7d3449 MG |
810 | return COMPACT_PARTIAL; |
811 | ||
812 | return COMPACT_CONTINUE; | |
813 | } | |
814 | ||
748446bb MG |
815 | static int compact_zone(struct zone *zone, struct compact_control *cc) |
816 | { | |
817 | int ret; | |
818 | ||
3e7d3449 MG |
819 | ret = compaction_suitable(zone, cc->order); |
820 | switch (ret) { | |
821 | case COMPACT_PARTIAL: | |
822 | case COMPACT_SKIPPED: | |
823 | /* Compaction is likely to fail */ | |
824 | return ret; | |
825 | case COMPACT_CONTINUE: | |
826 | /* Fall through to compaction */ | |
827 | ; | |
828 | } | |
829 | ||
748446bb MG |
830 | /* Setup to move all movable pages to the end of the zone */ |
831 | cc->migrate_pfn = zone->zone_start_pfn; | |
7db8889a RR |
832 | |
833 | if (cc->order > 0) { | |
834 | /* Incremental compaction. Start where the last one stopped. */ | |
835 | cc->free_pfn = zone->compact_cached_free_pfn; | |
836 | cc->start_free_pfn = cc->free_pfn; | |
837 | } else { | |
838 | /* Order == -1 starts at the end of the zone. */ | |
839 | cc->free_pfn = start_free_pfn(zone); | |
840 | } | |
748446bb MG |
841 | |
842 | migrate_prep_local(); | |
843 | ||
844 | while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) { | |
845 | unsigned long nr_migrate, nr_remaining; | |
9d502c1c | 846 | int err; |
748446bb | 847 | |
f9e35b3b MG |
848 | switch (isolate_migratepages(zone, cc)) { |
849 | case ISOLATE_ABORT: | |
850 | ret = COMPACT_PARTIAL; | |
851 | goto out; | |
852 | case ISOLATE_NONE: | |
748446bb | 853 | continue; |
f9e35b3b MG |
854 | case ISOLATE_SUCCESS: |
855 | ; | |
856 | } | |
748446bb MG |
857 | |
858 | nr_migrate = cc->nr_migratepages; | |
9d502c1c | 859 | err = migrate_pages(&cc->migratepages, compaction_alloc, |
68e3e926 LT |
860 | (unsigned long)cc, false, |
861 | cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC); | |
748446bb MG |
862 | update_nr_listpages(cc); |
863 | nr_remaining = cc->nr_migratepages; | |
864 | ||
865 | count_vm_event(COMPACTBLOCKS); | |
866 | count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining); | |
867 | if (nr_remaining) | |
868 | count_vm_events(COMPACTPAGEFAILED, nr_remaining); | |
b7aba698 MG |
869 | trace_mm_compaction_migratepages(nr_migrate - nr_remaining, |
870 | nr_remaining); | |
748446bb MG |
871 | |
872 | /* Release LRU pages not migrated */ | |
9d502c1c | 873 | if (err) { |
748446bb MG |
874 | putback_lru_pages(&cc->migratepages); |
875 | cc->nr_migratepages = 0; | |
4bf2bba3 DR |
876 | if (err == -ENOMEM) { |
877 | ret = COMPACT_PARTIAL; | |
878 | goto out; | |
879 | } | |
748446bb | 880 | } |
1fb3f8ca MG |
881 | |
882 | /* Capture a page now if it is a suitable size */ | |
883 | compact_capture_page(cc); | |
748446bb MG |
884 | } |
885 | ||
f9e35b3b | 886 | out: |
748446bb MG |
887 | /* Release free pages and check accounting */ |
888 | cc->nr_freepages -= release_freepages(&cc->freepages); | |
889 | VM_BUG_ON(cc->nr_freepages != 0); | |
890 | ||
891 | return ret; | |
892 | } | |
76ab0f53 | 893 | |
d43a87e6 | 894 | static unsigned long compact_zone_order(struct zone *zone, |
5a03b051 | 895 | int order, gfp_t gfp_mask, |
1fb3f8ca MG |
896 | bool sync, bool *contended, |
897 | struct page **page) | |
56de7263 MG |
898 | { |
899 | struct compact_control cc = { | |
900 | .nr_freepages = 0, | |
901 | .nr_migratepages = 0, | |
902 | .order = order, | |
903 | .migratetype = allocflags_to_migratetype(gfp_mask), | |
904 | .zone = zone, | |
68e3e926 | 905 | .sync = sync, |
c67fe375 | 906 | .contended = contended, |
1fb3f8ca | 907 | .page = page, |
56de7263 MG |
908 | }; |
909 | INIT_LIST_HEAD(&cc.freepages); | |
910 | INIT_LIST_HEAD(&cc.migratepages); | |
911 | ||
68e3e926 | 912 | return compact_zone(zone, &cc); |
56de7263 MG |
913 | } |
914 | ||
5e771905 MG |
915 | int sysctl_extfrag_threshold = 500; |
916 | ||
56de7263 MG |
917 | /** |
918 | * try_to_compact_pages - Direct compact to satisfy a high-order allocation | |
919 | * @zonelist: The zonelist used for the current allocation | |
920 | * @order: The order of the current allocation | |
921 | * @gfp_mask: The GFP mask of the current allocation | |
922 | * @nodemask: The allowed nodes to allocate from | |
77f1fe6b | 923 | * @sync: Whether migration is synchronous or not |
56de7263 MG |
924 | * |
925 | * This is the main entry point for direct page compaction. | |
926 | */ | |
927 | unsigned long try_to_compact_pages(struct zonelist *zonelist, | |
77f1fe6b | 928 | int order, gfp_t gfp_mask, nodemask_t *nodemask, |
1fb3f8ca | 929 | bool sync, bool *contended, struct page **page) |
56de7263 MG |
930 | { |
931 | enum zone_type high_zoneidx = gfp_zone(gfp_mask); | |
932 | int may_enter_fs = gfp_mask & __GFP_FS; | |
933 | int may_perform_io = gfp_mask & __GFP_IO; | |
56de7263 MG |
934 | struct zoneref *z; |
935 | struct zone *zone; | |
936 | int rc = COMPACT_SKIPPED; | |
937 | ||
4ffb6335 | 938 | /* Check if the GFP flags allow compaction */ |
c5a73c3d | 939 | if (!order || !may_enter_fs || !may_perform_io) |
56de7263 MG |
940 | return rc; |
941 | ||
942 | count_vm_event(COMPACTSTALL); | |
943 | ||
944 | /* Compact each zone in the list */ | |
945 | for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, | |
946 | nodemask) { | |
56de7263 MG |
947 | int status; |
948 | ||
c67fe375 | 949 | status = compact_zone_order(zone, order, gfp_mask, sync, |
1fb3f8ca | 950 | contended, page); |
56de7263 MG |
951 | rc = max(status, rc); |
952 | ||
3e7d3449 MG |
953 | /* If a normal allocation would succeed, stop compacting */ |
954 | if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0)) | |
56de7263 MG |
955 | break; |
956 | } | |
957 | ||
958 | return rc; | |
959 | } | |
960 | ||
961 | ||
76ab0f53 | 962 | /* Compact all zones within a node */ |
7be62de9 | 963 | static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) |
76ab0f53 MG |
964 | { |
965 | int zoneid; | |
76ab0f53 MG |
966 | struct zone *zone; |
967 | ||
76ab0f53 | 968 | for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) { |
76ab0f53 MG |
969 | |
970 | zone = &pgdat->node_zones[zoneid]; | |
971 | if (!populated_zone(zone)) | |
972 | continue; | |
973 | ||
7be62de9 RR |
974 | cc->nr_freepages = 0; |
975 | cc->nr_migratepages = 0; | |
976 | cc->zone = zone; | |
977 | INIT_LIST_HEAD(&cc->freepages); | |
978 | INIT_LIST_HEAD(&cc->migratepages); | |
76ab0f53 | 979 | |
aad6ec37 | 980 | if (cc->order == -1 || !compaction_deferred(zone, cc->order)) |
7be62de9 | 981 | compact_zone(zone, cc); |
76ab0f53 | 982 | |
aff62249 RR |
983 | if (cc->order > 0) { |
984 | int ok = zone_watermark_ok(zone, cc->order, | |
985 | low_wmark_pages(zone), 0, 0); | |
c81758fb | 986 | if (ok && cc->order >= zone->compact_order_failed) |
aff62249 RR |
987 | zone->compact_order_failed = cc->order + 1; |
988 | /* Currently async compaction is never deferred. */ | |
68e3e926 | 989 | else if (!ok && cc->sync) |
aff62249 RR |
990 | defer_compaction(zone, cc->order); |
991 | } | |
992 | ||
7be62de9 RR |
993 | VM_BUG_ON(!list_empty(&cc->freepages)); |
994 | VM_BUG_ON(!list_empty(&cc->migratepages)); | |
76ab0f53 MG |
995 | } |
996 | ||
997 | return 0; | |
998 | } | |
999 | ||
7be62de9 RR |
1000 | int compact_pgdat(pg_data_t *pgdat, int order) |
1001 | { | |
1002 | struct compact_control cc = { | |
1003 | .order = order, | |
68e3e926 | 1004 | .sync = false, |
1fb3f8ca | 1005 | .page = NULL, |
7be62de9 RR |
1006 | }; |
1007 | ||
1008 | return __compact_pgdat(pgdat, &cc); | |
1009 | } | |
1010 | ||
1011 | static int compact_node(int nid) | |
1012 | { | |
7be62de9 RR |
1013 | struct compact_control cc = { |
1014 | .order = -1, | |
68e3e926 | 1015 | .sync = true, |
1fb3f8ca | 1016 | .page = NULL, |
7be62de9 RR |
1017 | }; |
1018 | ||
8575ec29 | 1019 | return __compact_pgdat(NODE_DATA(nid), &cc); |
7be62de9 RR |
1020 | } |
1021 | ||
76ab0f53 MG |
1022 | /* Compact all nodes in the system */ |
1023 | static int compact_nodes(void) | |
1024 | { | |
1025 | int nid; | |
1026 | ||
8575ec29 HD |
1027 | /* Flush pending updates to the LRU lists */ |
1028 | lru_add_drain_all(); | |
1029 | ||
76ab0f53 MG |
1030 | for_each_online_node(nid) |
1031 | compact_node(nid); | |
1032 | ||
1033 | return COMPACT_COMPLETE; | |
1034 | } | |
1035 | ||
1036 | /* The written value is actually unused, all memory is compacted */ | |
1037 | int sysctl_compact_memory; | |
1038 | ||
1039 | /* This is the entry point for compacting all nodes via /proc/sys/vm */ | |
1040 | int sysctl_compaction_handler(struct ctl_table *table, int write, | |
1041 | void __user *buffer, size_t *length, loff_t *ppos) | |
1042 | { | |
1043 | if (write) | |
1044 | return compact_nodes(); | |
1045 | ||
1046 | return 0; | |
1047 | } | |
ed4a6d7f | 1048 | |
5e771905 MG |
1049 | int sysctl_extfrag_handler(struct ctl_table *table, int write, |
1050 | void __user *buffer, size_t *length, loff_t *ppos) | |
1051 | { | |
1052 | proc_dointvec_minmax(table, write, buffer, length, ppos); | |
1053 | ||
1054 | return 0; | |
1055 | } | |
1056 | ||
ed4a6d7f | 1057 | #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
10fbcf4c KS |
1058 | ssize_t sysfs_compact_node(struct device *dev, |
1059 | struct device_attribute *attr, | |
ed4a6d7f MG |
1060 | const char *buf, size_t count) |
1061 | { | |
8575ec29 HD |
1062 | int nid = dev->id; |
1063 | ||
1064 | if (nid >= 0 && nid < nr_node_ids && node_online(nid)) { | |
1065 | /* Flush pending updates to the LRU lists */ | |
1066 | lru_add_drain_all(); | |
1067 | ||
1068 | compact_node(nid); | |
1069 | } | |
ed4a6d7f MG |
1070 | |
1071 | return count; | |
1072 | } | |
10fbcf4c | 1073 | static DEVICE_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node); |
ed4a6d7f MG |
1074 | |
1075 | int compaction_register_node(struct node *node) | |
1076 | { | |
10fbcf4c | 1077 | return device_create_file(&node->dev, &dev_attr_compact); |
ed4a6d7f MG |
1078 | } |
1079 | ||
1080 | void compaction_unregister_node(struct node *node) | |
1081 | { | |
10fbcf4c | 1082 | return device_remove_file(&node->dev, &dev_attr_compact); |
ed4a6d7f MG |
1083 | } |
1084 | #endif /* CONFIG_SYSFS && CONFIG_NUMA */ | |
ff9543fd MN |
1085 | |
1086 | #endif /* CONFIG_COMPACTION */ |