vmscan: isolate_lru_pages(): stop neighbour search if neighbour cannot be isolated
authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tue, 26 Oct 2010 21:21:44 +0000 (14:21 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 26 Oct 2010 23:52:07 +0000 (16:52 -0700)
commit08fc468f4eaf6683bae5bdb94743a09d8630cb80
treea2225421eb8e01a8e9df588f5064be81059af91a
parent47185052165a4c5de0a461018238375dd982c2ec
vmscan: isolate_lru_pages(): stop neighbour search if neighbour cannot be isolated

isolate_lru_pages() does not just isolate LRU tail pages, but also
isolates neighbour pages of the eviction page.  The neighbour search does
not stop even if neighbours cannot be isolated which is excessive as the
lumpy reclaim will no longer result in a successful higher order
allocation.  This patch stops the PFN neighbour pages if an isolation
fails and moves on to the next block.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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>
mm/vmscan.c