]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm, thp: abort compaction if migration page cannot be charged to memcg
authorDavid Rientjes <rientjes@google.com>
Wed, 11 Jul 2012 21:02:13 +0000 (14:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Jul 2012 23:04:43 +0000 (16:04 -0700)
commit4bf2bba3750f10aa9e62e6949bc7e8329990f01b
tree8e0eb9acc97fed0ea070dda3f97326ee0fbd9316
parent4229fb1dc6843c49a14bb098719f8a696cdc44f8
mm, thp: abort compaction if migration page cannot be charged to memcg

If page migration cannot charge the temporary page to the memcg,
migrate_pages() will return -ENOMEM.  This isn't considered in memory
compaction however, and the loop continues to iterate over all
pageblocks trying to isolate and migrate pages.  If a small number of
very large memcgs happen to be oom, however, these attempts will mostly
be futile leading to an enormous amout of cpu consumption due to the
page migration failures.

This patch will short circuit and fail memory compaction if
migrate_pages() returns -ENOMEM.  COMPACT_PARTIAL is returned in case
some migrations were successful so that the page allocator will retry.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/compaction.c