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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 | ||
b7aba698 MG |
19 | #define CREATE_TRACE_POINTS |
20 | #include <trace/events/compaction.h> | |
21 | ||
748446bb MG |
22 | /* |
23 | * compact_control is used to track pages being migrated and the free pages | |
24 | * they are being migrated to during memory compaction. The free_pfn starts | |
25 | * at the end of a zone and migrate_pfn begins at the start. Movable pages | |
26 | * are moved to the end of a zone during a compaction run and the run | |
27 | * completes when free_pfn <= migrate_pfn | |
28 | */ | |
29 | struct compact_control { | |
30 | struct list_head freepages; /* List of free pages to migrate to */ | |
31 | struct list_head migratepages; /* List of pages being migrated */ | |
32 | unsigned long nr_freepages; /* Number of isolated free pages */ | |
33 | unsigned long nr_migratepages; /* Number of pages to migrate */ | |
34 | unsigned long free_pfn; /* isolate_freepages search base */ | |
35 | unsigned long migrate_pfn; /* isolate_migratepages search base */ | |
36 | ||
37 | /* Account for isolated anon and file pages */ | |
38 | unsigned long nr_anon; | |
39 | unsigned long nr_file; | |
40 | ||
56de7263 MG |
41 | unsigned int order; /* order a direct compactor needs */ |
42 | int migratetype; /* MOVABLE, RECLAIMABLE etc */ | |
748446bb MG |
43 | struct zone *zone; |
44 | }; | |
45 | ||
46 | static unsigned long release_freepages(struct list_head *freelist) | |
47 | { | |
48 | struct page *page, *next; | |
49 | unsigned long count = 0; | |
50 | ||
51 | list_for_each_entry_safe(page, next, freelist, lru) { | |
52 | list_del(&page->lru); | |
53 | __free_page(page); | |
54 | count++; | |
55 | } | |
56 | ||
57 | return count; | |
58 | } | |
59 | ||
60 | /* Isolate free pages onto a private freelist. Must hold zone->lock */ | |
61 | static unsigned long isolate_freepages_block(struct zone *zone, | |
62 | unsigned long blockpfn, | |
63 | struct list_head *freelist) | |
64 | { | |
65 | unsigned long zone_end_pfn, end_pfn; | |
b7aba698 | 66 | int nr_scanned = 0, total_isolated = 0; |
748446bb MG |
67 | struct page *cursor; |
68 | ||
69 | /* Get the last PFN we should scan for free pages at */ | |
70 | zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; | |
71 | end_pfn = min(blockpfn + pageblock_nr_pages, zone_end_pfn); | |
72 | ||
73 | /* Find the first usable PFN in the block to initialse page cursor */ | |
74 | for (; blockpfn < end_pfn; blockpfn++) { | |
75 | if (pfn_valid_within(blockpfn)) | |
76 | break; | |
77 | } | |
78 | cursor = pfn_to_page(blockpfn); | |
79 | ||
80 | /* Isolate free pages. This assumes the block is valid */ | |
81 | for (; blockpfn < end_pfn; blockpfn++, cursor++) { | |
82 | int isolated, i; | |
83 | struct page *page = cursor; | |
84 | ||
85 | if (!pfn_valid_within(blockpfn)) | |
86 | continue; | |
b7aba698 | 87 | nr_scanned++; |
748446bb MG |
88 | |
89 | if (!PageBuddy(page)) | |
90 | continue; | |
91 | ||
92 | /* Found a free page, break it into order-0 pages */ | |
93 | isolated = split_free_page(page); | |
94 | total_isolated += isolated; | |
95 | for (i = 0; i < isolated; i++) { | |
96 | list_add(&page->lru, freelist); | |
97 | page++; | |
98 | } | |
99 | ||
100 | /* If a page was split, advance to the end of it */ | |
101 | if (isolated) { | |
102 | blockpfn += isolated - 1; | |
103 | cursor += isolated - 1; | |
104 | } | |
105 | } | |
106 | ||
b7aba698 | 107 | trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated); |
748446bb MG |
108 | return total_isolated; |
109 | } | |
110 | ||
111 | /* Returns true if the page is within a block suitable for migration to */ | |
112 | static bool suitable_migration_target(struct page *page) | |
113 | { | |
114 | ||
115 | int migratetype = get_pageblock_migratetype(page); | |
116 | ||
117 | /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */ | |
118 | if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE) | |
119 | return false; | |
120 | ||
121 | /* If the page is a large free page, then allow migration */ | |
122 | if (PageBuddy(page) && page_order(page) >= pageblock_order) | |
123 | return true; | |
124 | ||
125 | /* If the block is MIGRATE_MOVABLE, allow migration */ | |
126 | if (migratetype == MIGRATE_MOVABLE) | |
127 | return true; | |
128 | ||
129 | /* Otherwise skip the block */ | |
130 | return false; | |
131 | } | |
132 | ||
133 | /* | |
134 | * Based on information in the current compact_control, find blocks | |
135 | * suitable for isolating free pages from and then isolate them. | |
136 | */ | |
137 | static void isolate_freepages(struct zone *zone, | |
138 | struct compact_control *cc) | |
139 | { | |
140 | struct page *page; | |
141 | unsigned long high_pfn, low_pfn, pfn; | |
142 | unsigned long flags; | |
143 | int nr_freepages = cc->nr_freepages; | |
144 | struct list_head *freelist = &cc->freepages; | |
145 | ||
146 | pfn = cc->free_pfn; | |
147 | low_pfn = cc->migrate_pfn + pageblock_nr_pages; | |
148 | high_pfn = low_pfn; | |
149 | ||
150 | /* | |
151 | * Isolate free pages until enough are available to migrate the | |
152 | * pages on cc->migratepages. We stop searching if the migrate | |
153 | * and free page scanners meet or enough free pages are isolated. | |
154 | */ | |
155 | spin_lock_irqsave(&zone->lock, flags); | |
156 | for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; | |
157 | pfn -= pageblock_nr_pages) { | |
158 | unsigned long isolated; | |
159 | ||
160 | if (!pfn_valid(pfn)) | |
161 | continue; | |
162 | ||
163 | /* | |
164 | * Check for overlapping nodes/zones. It's possible on some | |
165 | * configurations to have a setup like | |
166 | * node0 node1 node0 | |
167 | * i.e. it's possible that all pages within a zones range of | |
168 | * pages do not belong to a single zone. | |
169 | */ | |
170 | page = pfn_to_page(pfn); | |
171 | if (page_zone(page) != zone) | |
172 | continue; | |
173 | ||
174 | /* Check the block is suitable for migration */ | |
175 | if (!suitable_migration_target(page)) | |
176 | continue; | |
177 | ||
178 | /* Found a block suitable for isolating free pages from */ | |
179 | isolated = isolate_freepages_block(zone, pfn, freelist); | |
180 | nr_freepages += isolated; | |
181 | ||
182 | /* | |
183 | * Record the highest PFN we isolated pages from. When next | |
184 | * looking for free pages, the search will restart here as | |
185 | * page migration may have returned some pages to the allocator | |
186 | */ | |
187 | if (isolated) | |
188 | high_pfn = max(high_pfn, pfn); | |
189 | } | |
190 | spin_unlock_irqrestore(&zone->lock, flags); | |
191 | ||
192 | /* split_free_page does not map the pages */ | |
193 | list_for_each_entry(page, freelist, lru) { | |
194 | arch_alloc_page(page, 0); | |
195 | kernel_map_pages(page, 1, 1); | |
196 | } | |
197 | ||
198 | cc->free_pfn = high_pfn; | |
199 | cc->nr_freepages = nr_freepages; | |
200 | } | |
201 | ||
202 | /* Update the number of anon and file isolated pages in the zone */ | |
203 | static void acct_isolated(struct zone *zone, struct compact_control *cc) | |
204 | { | |
205 | struct page *page; | |
206 | unsigned int count[NR_LRU_LISTS] = { 0, }; | |
207 | ||
208 | list_for_each_entry(page, &cc->migratepages, lru) { | |
209 | int lru = page_lru_base_type(page); | |
210 | count[lru]++; | |
211 | } | |
212 | ||
213 | cc->nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; | |
214 | cc->nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; | |
215 | __mod_zone_page_state(zone, NR_ISOLATED_ANON, cc->nr_anon); | |
216 | __mod_zone_page_state(zone, NR_ISOLATED_FILE, cc->nr_file); | |
217 | } | |
218 | ||
219 | /* Similar to reclaim, but different enough that they don't share logic */ | |
220 | static bool too_many_isolated(struct zone *zone) | |
221 | { | |
bc693045 | 222 | unsigned long active, inactive, isolated; |
748446bb MG |
223 | |
224 | inactive = zone_page_state(zone, NR_INACTIVE_FILE) + | |
225 | zone_page_state(zone, NR_INACTIVE_ANON); | |
bc693045 MK |
226 | active = zone_page_state(zone, NR_ACTIVE_FILE) + |
227 | zone_page_state(zone, NR_ACTIVE_ANON); | |
748446bb MG |
228 | isolated = zone_page_state(zone, NR_ISOLATED_FILE) + |
229 | zone_page_state(zone, NR_ISOLATED_ANON); | |
230 | ||
bc693045 | 231 | return isolated > (inactive + active) / 2; |
748446bb MG |
232 | } |
233 | ||
234 | /* | |
235 | * Isolate all pages that can be migrated from the block pointed to by | |
236 | * the migrate scanner within compact_control. | |
237 | */ | |
238 | static unsigned long isolate_migratepages(struct zone *zone, | |
239 | struct compact_control *cc) | |
240 | { | |
241 | unsigned long low_pfn, end_pfn; | |
b7aba698 | 242 | unsigned long nr_scanned = 0, nr_isolated = 0; |
748446bb MG |
243 | struct list_head *migratelist = &cc->migratepages; |
244 | ||
245 | /* Do not scan outside zone boundaries */ | |
246 | low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn); | |
247 | ||
248 | /* Only scan within a pageblock boundary */ | |
249 | end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages); | |
250 | ||
251 | /* Do not cross the free scanner or scan within a memory hole */ | |
252 | if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) { | |
253 | cc->migrate_pfn = end_pfn; | |
254 | return 0; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Ensure that there are not too many pages isolated from the LRU | |
259 | * list by either parallel reclaimers or compaction. If there are, | |
260 | * delay for some time until fewer pages are isolated | |
261 | */ | |
262 | while (unlikely(too_many_isolated(zone))) { | |
263 | congestion_wait(BLK_RW_ASYNC, HZ/10); | |
264 | ||
265 | if (fatal_signal_pending(current)) | |
266 | return 0; | |
267 | } | |
268 | ||
269 | /* Time to isolate some pages for migration */ | |
270 | spin_lock_irq(&zone->lru_lock); | |
271 | for (; low_pfn < end_pfn; low_pfn++) { | |
272 | struct page *page; | |
273 | if (!pfn_valid_within(low_pfn)) | |
274 | continue; | |
b7aba698 | 275 | nr_scanned++; |
748446bb MG |
276 | |
277 | /* Get the page and skip if free */ | |
278 | page = pfn_to_page(low_pfn); | |
279 | if (PageBuddy(page)) | |
280 | continue; | |
281 | ||
282 | /* Try isolate the page */ | |
283 | if (__isolate_lru_page(page, ISOLATE_BOTH, 0) != 0) | |
284 | continue; | |
285 | ||
286 | /* Successfully isolated */ | |
287 | del_page_from_lru_list(zone, page, page_lru(page)); | |
288 | list_add(&page->lru, migratelist); | |
748446bb | 289 | cc->nr_migratepages++; |
b7aba698 | 290 | nr_isolated++; |
748446bb MG |
291 | |
292 | /* Avoid isolating too much */ | |
293 | if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) | |
294 | break; | |
295 | } | |
296 | ||
297 | acct_isolated(zone, cc); | |
298 | ||
299 | spin_unlock_irq(&zone->lru_lock); | |
300 | cc->migrate_pfn = low_pfn; | |
301 | ||
b7aba698 MG |
302 | trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated); |
303 | ||
748446bb MG |
304 | return cc->nr_migratepages; |
305 | } | |
306 | ||
307 | /* | |
308 | * This is a migrate-callback that "allocates" freepages by taking pages | |
309 | * from the isolated freelists in the block we are migrating to. | |
310 | */ | |
311 | static struct page *compaction_alloc(struct page *migratepage, | |
312 | unsigned long data, | |
313 | int **result) | |
314 | { | |
315 | struct compact_control *cc = (struct compact_control *)data; | |
316 | struct page *freepage; | |
317 | ||
318 | /* Isolate free pages if necessary */ | |
319 | if (list_empty(&cc->freepages)) { | |
320 | isolate_freepages(cc->zone, cc); | |
321 | ||
322 | if (list_empty(&cc->freepages)) | |
323 | return NULL; | |
324 | } | |
325 | ||
326 | freepage = list_entry(cc->freepages.next, struct page, lru); | |
327 | list_del(&freepage->lru); | |
328 | cc->nr_freepages--; | |
329 | ||
330 | return freepage; | |
331 | } | |
332 | ||
333 | /* | |
334 | * We cannot control nr_migratepages and nr_freepages fully when migration is | |
335 | * running as migrate_pages() has no knowledge of compact_control. When | |
336 | * migration is complete, we count the number of pages on the lists by hand. | |
337 | */ | |
338 | static void update_nr_listpages(struct compact_control *cc) | |
339 | { | |
340 | int nr_migratepages = 0; | |
341 | int nr_freepages = 0; | |
342 | struct page *page; | |
343 | ||
344 | list_for_each_entry(page, &cc->migratepages, lru) | |
345 | nr_migratepages++; | |
346 | list_for_each_entry(page, &cc->freepages, lru) | |
347 | nr_freepages++; | |
348 | ||
349 | cc->nr_migratepages = nr_migratepages; | |
350 | cc->nr_freepages = nr_freepages; | |
351 | } | |
352 | ||
353 | static int compact_finished(struct zone *zone, | |
354 | struct compact_control *cc) | |
355 | { | |
56de7263 MG |
356 | unsigned int order; |
357 | unsigned long watermark = low_wmark_pages(zone) + (1 << cc->order); | |
358 | ||
748446bb MG |
359 | if (fatal_signal_pending(current)) |
360 | return COMPACT_PARTIAL; | |
361 | ||
362 | /* Compaction run completes if the migrate and free scanner meet */ | |
363 | if (cc->free_pfn <= cc->migrate_pfn) | |
364 | return COMPACT_COMPLETE; | |
365 | ||
56de7263 MG |
366 | /* Compaction run is not finished if the watermark is not met */ |
367 | if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0)) | |
368 | return COMPACT_CONTINUE; | |
369 | ||
370 | if (cc->order == -1) | |
371 | return COMPACT_CONTINUE; | |
372 | ||
373 | /* Direct compactor: Is a suitable page free? */ | |
374 | for (order = cc->order; order < MAX_ORDER; order++) { | |
375 | /* Job done if page is free of the right migratetype */ | |
376 | if (!list_empty(&zone->free_area[order].free_list[cc->migratetype])) | |
377 | return COMPACT_PARTIAL; | |
378 | ||
379 | /* Job done if allocation would set block type */ | |
380 | if (order >= pageblock_order && zone->free_area[order].nr_free) | |
381 | return COMPACT_PARTIAL; | |
382 | } | |
383 | ||
748446bb MG |
384 | return COMPACT_CONTINUE; |
385 | } | |
386 | ||
3e7d3449 MG |
387 | /* |
388 | * compaction_suitable: Is this suitable to run compaction on this zone now? | |
389 | * Returns | |
390 | * COMPACT_SKIPPED - If there are too few free pages for compaction | |
391 | * COMPACT_PARTIAL - If the allocation would succeed without compaction | |
392 | * COMPACT_CONTINUE - If compaction should run now | |
393 | */ | |
394 | unsigned long compaction_suitable(struct zone *zone, int order) | |
395 | { | |
396 | int fragindex; | |
397 | unsigned long watermark; | |
398 | ||
399 | /* | |
400 | * Watermarks for order-0 must be met for compaction. Note the 2UL. | |
401 | * This is because during migration, copies of pages need to be | |
402 | * allocated and for a short time, the footprint is higher | |
403 | */ | |
404 | watermark = low_wmark_pages(zone) + (2UL << order); | |
405 | if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) | |
406 | return COMPACT_SKIPPED; | |
407 | ||
408 | /* | |
409 | * fragmentation index determines if allocation failures are due to | |
410 | * low memory or external fragmentation | |
411 | * | |
412 | * index of -1 implies allocations might succeed dependingon watermarks | |
413 | * index towards 0 implies failure is due to lack of memory | |
414 | * index towards 1000 implies failure is due to fragmentation | |
415 | * | |
416 | * Only compact if a failure would be due to fragmentation. | |
417 | */ | |
418 | fragindex = fragmentation_index(zone, order); | |
419 | if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold) | |
420 | return COMPACT_SKIPPED; | |
421 | ||
422 | if (fragindex == -1 && zone_watermark_ok(zone, order, watermark, 0, 0)) | |
423 | return COMPACT_PARTIAL; | |
424 | ||
425 | return COMPACT_CONTINUE; | |
426 | } | |
427 | ||
748446bb MG |
428 | static int compact_zone(struct zone *zone, struct compact_control *cc) |
429 | { | |
430 | int ret; | |
431 | ||
3e7d3449 MG |
432 | ret = compaction_suitable(zone, cc->order); |
433 | switch (ret) { | |
434 | case COMPACT_PARTIAL: | |
435 | case COMPACT_SKIPPED: | |
436 | /* Compaction is likely to fail */ | |
437 | return ret; | |
438 | case COMPACT_CONTINUE: | |
439 | /* Fall through to compaction */ | |
440 | ; | |
441 | } | |
442 | ||
748446bb MG |
443 | /* Setup to move all movable pages to the end of the zone */ |
444 | cc->migrate_pfn = zone->zone_start_pfn; | |
445 | cc->free_pfn = cc->migrate_pfn + zone->spanned_pages; | |
446 | cc->free_pfn &= ~(pageblock_nr_pages-1); | |
447 | ||
448 | migrate_prep_local(); | |
449 | ||
450 | while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) { | |
451 | unsigned long nr_migrate, nr_remaining; | |
452 | ||
453 | if (!isolate_migratepages(zone, cc)) | |
454 | continue; | |
455 | ||
456 | nr_migrate = cc->nr_migratepages; | |
457 | migrate_pages(&cc->migratepages, compaction_alloc, | |
458 | (unsigned long)cc, 0); | |
459 | update_nr_listpages(cc); | |
460 | nr_remaining = cc->nr_migratepages; | |
461 | ||
462 | count_vm_event(COMPACTBLOCKS); | |
463 | count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining); | |
464 | if (nr_remaining) | |
465 | count_vm_events(COMPACTPAGEFAILED, nr_remaining); | |
b7aba698 MG |
466 | trace_mm_compaction_migratepages(nr_migrate - nr_remaining, |
467 | nr_remaining); | |
748446bb MG |
468 | |
469 | /* Release LRU pages not migrated */ | |
470 | if (!list_empty(&cc->migratepages)) { | |
471 | putback_lru_pages(&cc->migratepages); | |
472 | cc->nr_migratepages = 0; | |
473 | } | |
474 | ||
475 | } | |
476 | ||
477 | /* Release free pages and check accounting */ | |
478 | cc->nr_freepages -= release_freepages(&cc->freepages); | |
479 | VM_BUG_ON(cc->nr_freepages != 0); | |
480 | ||
481 | return ret; | |
482 | } | |
76ab0f53 | 483 | |
3e7d3449 | 484 | unsigned long compact_zone_order(struct zone *zone, |
56de7263 MG |
485 | int order, gfp_t gfp_mask) |
486 | { | |
487 | struct compact_control cc = { | |
488 | .nr_freepages = 0, | |
489 | .nr_migratepages = 0, | |
490 | .order = order, | |
491 | .migratetype = allocflags_to_migratetype(gfp_mask), | |
492 | .zone = zone, | |
493 | }; | |
494 | INIT_LIST_HEAD(&cc.freepages); | |
495 | INIT_LIST_HEAD(&cc.migratepages); | |
496 | ||
497 | return compact_zone(zone, &cc); | |
498 | } | |
499 | ||
5e771905 MG |
500 | int sysctl_extfrag_threshold = 500; |
501 | ||
56de7263 MG |
502 | /** |
503 | * try_to_compact_pages - Direct compact to satisfy a high-order allocation | |
504 | * @zonelist: The zonelist used for the current allocation | |
505 | * @order: The order of the current allocation | |
506 | * @gfp_mask: The GFP mask of the current allocation | |
507 | * @nodemask: The allowed nodes to allocate from | |
508 | * | |
509 | * This is the main entry point for direct page compaction. | |
510 | */ | |
511 | unsigned long try_to_compact_pages(struct zonelist *zonelist, | |
512 | int order, gfp_t gfp_mask, nodemask_t *nodemask) | |
513 | { | |
514 | enum zone_type high_zoneidx = gfp_zone(gfp_mask); | |
515 | int may_enter_fs = gfp_mask & __GFP_FS; | |
516 | int may_perform_io = gfp_mask & __GFP_IO; | |
56de7263 MG |
517 | struct zoneref *z; |
518 | struct zone *zone; | |
519 | int rc = COMPACT_SKIPPED; | |
520 | ||
521 | /* | |
522 | * Check whether it is worth even starting compaction. The order check is | |
523 | * made because an assumption is made that the page allocator can satisfy | |
524 | * the "cheaper" orders without taking special steps | |
525 | */ | |
526 | if (order <= PAGE_ALLOC_COSTLY_ORDER || !may_enter_fs || !may_perform_io) | |
527 | return rc; | |
528 | ||
529 | count_vm_event(COMPACTSTALL); | |
530 | ||
531 | /* Compact each zone in the list */ | |
532 | for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx, | |
533 | nodemask) { | |
56de7263 MG |
534 | int status; |
535 | ||
56de7263 MG |
536 | status = compact_zone_order(zone, order, gfp_mask); |
537 | rc = max(status, rc); | |
538 | ||
3e7d3449 MG |
539 | /* If a normal allocation would succeed, stop compacting */ |
540 | if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0)) | |
56de7263 MG |
541 | break; |
542 | } | |
543 | ||
544 | return rc; | |
545 | } | |
546 | ||
547 | ||
76ab0f53 MG |
548 | /* Compact all zones within a node */ |
549 | static int compact_node(int nid) | |
550 | { | |
551 | int zoneid; | |
552 | pg_data_t *pgdat; | |
553 | struct zone *zone; | |
554 | ||
555 | if (nid < 0 || nid >= nr_node_ids || !node_online(nid)) | |
556 | return -EINVAL; | |
557 | pgdat = NODE_DATA(nid); | |
558 | ||
559 | /* Flush pending updates to the LRU lists */ | |
560 | lru_add_drain_all(); | |
561 | ||
562 | for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) { | |
563 | struct compact_control cc = { | |
564 | .nr_freepages = 0, | |
565 | .nr_migratepages = 0, | |
56de7263 | 566 | .order = -1, |
76ab0f53 MG |
567 | }; |
568 | ||
569 | zone = &pgdat->node_zones[zoneid]; | |
570 | if (!populated_zone(zone)) | |
571 | continue; | |
572 | ||
573 | cc.zone = zone; | |
574 | INIT_LIST_HEAD(&cc.freepages); | |
575 | INIT_LIST_HEAD(&cc.migratepages); | |
576 | ||
577 | compact_zone(zone, &cc); | |
578 | ||
579 | VM_BUG_ON(!list_empty(&cc.freepages)); | |
580 | VM_BUG_ON(!list_empty(&cc.migratepages)); | |
581 | } | |
582 | ||
583 | return 0; | |
584 | } | |
585 | ||
586 | /* Compact all nodes in the system */ | |
587 | static int compact_nodes(void) | |
588 | { | |
589 | int nid; | |
590 | ||
591 | for_each_online_node(nid) | |
592 | compact_node(nid); | |
593 | ||
594 | return COMPACT_COMPLETE; | |
595 | } | |
596 | ||
597 | /* The written value is actually unused, all memory is compacted */ | |
598 | int sysctl_compact_memory; | |
599 | ||
600 | /* This is the entry point for compacting all nodes via /proc/sys/vm */ | |
601 | int sysctl_compaction_handler(struct ctl_table *table, int write, | |
602 | void __user *buffer, size_t *length, loff_t *ppos) | |
603 | { | |
604 | if (write) | |
605 | return compact_nodes(); | |
606 | ||
607 | return 0; | |
608 | } | |
ed4a6d7f | 609 | |
5e771905 MG |
610 | int sysctl_extfrag_handler(struct ctl_table *table, int write, |
611 | void __user *buffer, size_t *length, loff_t *ppos) | |
612 | { | |
613 | proc_dointvec_minmax(table, write, buffer, length, ppos); | |
614 | ||
615 | return 0; | |
616 | } | |
617 | ||
ed4a6d7f MG |
618 | #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) |
619 | ssize_t sysfs_compact_node(struct sys_device *dev, | |
620 | struct sysdev_attribute *attr, | |
621 | const char *buf, size_t count) | |
622 | { | |
623 | compact_node(dev->id); | |
624 | ||
625 | return count; | |
626 | } | |
627 | static SYSDEV_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node); | |
628 | ||
629 | int compaction_register_node(struct node *node) | |
630 | { | |
631 | return sysdev_create_file(&node->sysdev, &attr_compact); | |
632 | } | |
633 | ||
634 | void compaction_unregister_node(struct node *node) | |
635 | { | |
636 | return sysdev_remove_file(&node->sysdev, &attr_compact); | |
637 | } | |
638 | #endif /* CONFIG_SYSFS && CONFIG_NUMA */ |