]> www.infradead.org Git - users/jedix/linux-maple.git/commit
mm: compaction: make isolate_lru_page() filter-aware
authorMinchan Kim <minchan.kim@gmail.com>
Tue, 1 Nov 2011 00:06:51 +0000 (17:06 -0700)
committerJerry Snitselaar <jerry.snitselaar@oracle.com>
Sun, 7 Oct 2012 06:00:52 +0000 (23:00 -0700)
commit5bfc3c17385e248647ef700d08ecad5050569dbc
treef94e7d7c380e13aeca06178e130016c647ffbf5d
parentbccd43e4976d5be310df0e0b359af67e983af2f9
mm: compaction: make isolate_lru_page() filter-aware

commit 39deaf8585152f1a35c1676d3d7dc6ae0fb65967 upstream.

Stable note: Not tracked in Bugzilla. THP and compaction disrupt the LRU
list leading to poor reclaim decisions which has a variable
performance impact.

In async mode, compaction doesn't migrate dirty or writeback pages.  So,
it's meaningless to pick the page and re-add it to lru list.

Of course, when we isolate the page in compaction, the page might be dirty
or writeback but when we try to migrate the page, the page would be not
dirty, writeback.  So it could be migrated.  But it's very unlikely as
isolate and migration cycle is much faster than writeout.

So, this patch helps cpu overhead and prevent unnecessary LRU churning.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 19faec0520b3b16dfd58cde30938a3c4d3dcdd5b)

Signed-off-by: Jerry Snitselaar <jerry.snitselaar@oracle.com>
include/linux/mmzone.h
mm/compaction.c
mm/vmscan.c