tree 5e72498f44d4fcae18f29eb87dd05a849a7a23c9
parent 83fde0f22872aa8c1d46f775cc7bdfa864499e65
author Mel Gorman <mgorman@suse.de> 1349738952 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1349767341 +0900

mm: compaction: capture a suitable high-order page immediately when it is made available

While compaction is migrating pages to free up large contiguous blocks
for allocation it races with other allocation requests that may steal
these blocks or break them up.  This patch alters direct compaction to
capture a suitable free page as soon as it becomes available to reduce
this race.  It uses similar logic to split_free_page() to ensure that
watermarks are still obeyed.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>