From 6128cc0567321c5548e1a3cf1467eb3d682e21f6 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Mon, 7 Apr 2014 15:37:06 -0700 Subject: 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 Acked-by: Vlastimil Babka Cc: Mel Gorman Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman --- mm/compaction.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) (limited to 'mm') diff --git a/mm/compaction.c b/mm/compaction.c index f347b73be165..1791b4acffb5 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -526,8 +526,25 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, /* If isolation recently failed, do not retry */ pageblock_nr = low_pfn >> pageblock_order; - if (!isolation_suitable(cc, page)) - goto next_pageblock; + if (last_pageblock_nr != pageblock_nr) { + int mt; + + last_pageblock_nr = pageblock_nr; + if (!isolation_suitable(cc, page)) + goto next_pageblock; + + /* + * For async migration, also only scan in MOVABLE + * blocks. Async migration is optimistic to see if + * the minimum amount of work satisfies the allocation + */ + mt = get_pageblock_migratetype(page); + if (!cc->sync && !migrate_async_suitable(mt)) { + cc->finished_update_migrate = true; + skipped_async_unsuitable = true; + goto next_pageblock; + } + } /* * Skip if free. page_order cannot be used without zone->lock @@ -536,18 +553,6 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, if (PageBuddy(page)) continue; - /* - * For async migration, also only scan in MOVABLE blocks. Async - * migration is optimistic to see if the minimum amount of work - * satisfies the allocation - */ - if (!cc->sync && last_pageblock_nr != pageblock_nr && - !migrate_async_suitable(get_pageblock_migratetype(page))) { - cc->finished_update_migrate = true; - skipped_async_unsuitable = true; - goto next_pageblock; - } - /* * Check may be lockless but that's ok as we recheck later. * It's possible to migrate LRU pages and balloon pages @@ -639,7 +644,6 @@ check_compact_cluster: next_pageblock: low_pfn = ALIGN(low_pfn + 1, pageblock_nr_pages) - 1; - last_pageblock_nr = pageblock_nr; } acct_isolated(zone, locked, cc); -- cgit v1.2.3