From aff622495c9a0b56148192e53bdec539f5e147f2 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Wed, 21 Mar 2012 16:33:52 -0700 Subject: vmscan: only defer compaction for failed order and higher Currently a failed order-9 (transparent hugepage) compaction can lead to memory compaction being temporarily disabled for a memory zone. Even if we only need compaction for an order 2 allocation, eg. for jumbo frames networking. The fix is relatively straightforward: keep track of the highest order at which compaction is succeeding, and only defer compaction for orders at which compaction is failing. Signed-off-by: Rik van Riel Cc: Andrea Arcangeli Acked-by: Mel Gorman Cc: Johannes Weiner Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/compaction.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'include/linux/compaction.h') diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 7a9323aef4a3..51a90b7f2d60 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -34,20 +34,26 @@ extern unsigned long compaction_suitable(struct zone *zone, int order); * allocation success. 1 << compact_defer_limit compactions are skipped up * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT */ -static inline void defer_compaction(struct zone *zone) +static inline void defer_compaction(struct zone *zone, int order) { zone->compact_considered = 0; zone->compact_defer_shift++; + if (order < zone->compact_order_failed) + zone->compact_order_failed = order; + if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT) zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT; } /* Returns true if compaction should be skipped this time */ -static inline bool compaction_deferred(struct zone *zone) +static inline bool compaction_deferred(struct zone *zone, int order) { unsigned long defer_limit = 1UL << zone->compact_defer_shift; + if (order < zone->compact_order_failed) + return false; + /* Avoid possible overflow */ if (++zone->compact_considered > defer_limit) zone->compact_considered = defer_limit; @@ -73,11 +79,11 @@ static inline unsigned long compaction_suitable(struct zone *zone, int order) return COMPACT_SKIPPED; } -static inline void defer_compaction(struct zone *zone) +static inline void defer_compaction(struct zone *zone, int order) { } -static inline bool compaction_deferred(struct zone *zone) +static inline bool compaction_deferred(struct zone *zone, int order) { return 1; } -- cgit v1.2.3-59-g8ed1b