From e87de33ea3bb3e6a4cbeb126db2f1745cafc0ca0 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Fri, 28 Sep 2012 10:19:45 +1000 Subject: [PATCH] mm-compaction-acquire-the-zone-lru_lock-as-late-as-possible-fix augment comment Cc: Mel Gorman Signed-off-by: Andrew Morton --- mm/compaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index a0c1a08c4172..7d96f8b45aa8 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -415,7 +415,8 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, * if PageLRU is set) but the lock is not necessarily taken * here and it is wasteful to take it just to check transhuge. * Check transhuge without lock and skip if it's either a - * transhuge or hugetlbfs page. + * transhuge or hugetlbfs page because calling compound_order() + * requires lru_lock to exclude isolation and splitting. */ if (PageTransHuge(page)) { if (!locked) -- 2.39.2