Commit fc8dc0a9f5b062d2b5fbfe368e4d9cdff23ca76b
Committed by
Jiri Slaby
Jiri Slaby
1 parent
e45dcd3dea
Exists in
ti-linux-3.12.y
and in
2 other branches
mm/compaction: check pageblock suitability once per pageblock
commit c122b2087ab94192f2b937e47b563a9c4e688ece upstream. isolation_suitable() and migrate_async_suitable() is used to be sure that this pageblock range is fine to be migragted. It isn't needed to call it on every page. Current code do well if not suitable, but, don't do well when suitable. 1) It re-checks isolation_suitable() on each page of a pageblock that was already estabilished as suitable. 2) It re-checks migrate_async_suitable() on each page of a pageblock that was not entered through the next_pageblock: label, because last_pageblock_nr is not otherwise updated. This patch fixes situation by 1) calling isolation_suitable() only once per pageblock and 2) always updating last_pageblock_nr to the pageblock that was just checked. Additionally, move PageBuddy() check after pageblock unit check, since pageblock check is the first thing we should do and makes things more simple. [vbabka@suse.cz: rephrase commit description] Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Showing 1 changed file with 19 additions and 15 deletions Side-by-side Diff
mm/compaction.c
| ... | ... | @@ -527,26 +527,31 @@ |
| 527 | 527 | |
| 528 | 528 | /* If isolation recently failed, do not retry */ |
| 529 | 529 | pageblock_nr = low_pfn >> pageblock_order; |
| 530 | - if (!isolation_suitable(cc, page)) | |
| 531 | - goto next_pageblock; | |
| 530 | + if (last_pageblock_nr != pageblock_nr) { | |
| 531 | + int mt; | |
| 532 | 532 | |
| 533 | + last_pageblock_nr = pageblock_nr; | |
| 534 | + if (!isolation_suitable(cc, page)) | |
| 535 | + goto next_pageblock; | |
| 536 | + | |
| 537 | + /* | |
| 538 | + * For async migration, also only scan in MOVABLE | |
| 539 | + * blocks. Async migration is optimistic to see if | |
| 540 | + * the minimum amount of work satisfies the allocation | |
| 541 | + */ | |
| 542 | + mt = get_pageblock_migratetype(page); | |
| 543 | + if (!cc->sync && !migrate_async_suitable(mt)) { | |
| 544 | + cc->finished_update_migrate = true; | |
| 545 | + skipped_async_unsuitable = true; | |
| 546 | + goto next_pageblock; | |
| 547 | + } | |
| 548 | + } | |
| 549 | + | |
| 533 | 550 | /* Skip if free */ |
| 534 | 551 | if (PageBuddy(page)) |
| 535 | 552 | continue; |
| 536 | 553 | |
| 537 | 554 | /* |
| 538 | - * For async migration, also only scan in MOVABLE blocks. Async | |
| 539 | - * migration is optimistic to see if the minimum amount of work | |
| 540 | - * satisfies the allocation | |
| 541 | - */ | |
| 542 | - if (!cc->sync && last_pageblock_nr != pageblock_nr && | |
| 543 | - !migrate_async_suitable(get_pageblock_migratetype(page))) { | |
| 544 | - cc->finished_update_migrate = true; | |
| 545 | - skipped_async_unsuitable = true; | |
| 546 | - goto next_pageblock; | |
| 547 | - } | |
| 548 | - | |
| 549 | - /* | |
| 550 | 555 | * Check may be lockless but that's ok as we recheck later. |
| 551 | 556 | * It's possible to migrate LRU pages and balloon pages |
| 552 | 557 | * Skip any other type of page |
| ... | ... | @@ -637,7 +642,6 @@ |
| 637 | 642 | |
| 638 | 643 | next_pageblock: |
| 639 | 644 | low_pfn = ALIGN(low_pfn + 1, pageblock_nr_pages) - 1; |
| 640 | - last_pageblock_nr = pageblock_nr; | |
| 641 | 645 | } |
| 642 | 646 | |
| 643 | 647 | acct_isolated(zone, locked, cc); |