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