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Commit e746bf73 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Linus Torvalds
Browse files

mm,page_alloc: don't call __node_reclaim() with oom_lock held. 

We are doing a last second memory allocation attempt before calling
out_of_memory().  But since slab shrinker functions might indirectly
wait for other thread's __GFP_DIRECT_RECLAIM && !__GFP_NORETRY memory
allocations via sleeping locks, calling slab shrinker functions from
node_reclaim() from get_page_from_freelist() with oom_lock held has
possibility of deadlock.  Therefore, make sure that last second memory
allocation attempt does not call slab shrinker functions.

Link: http://lkml.kernel.org/r/1503577106-9196-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp


Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 42ff72cf

mm/page_alloc.c

+6 −3
Original line number Diff line number Diff line
@@ -3291,9 +3291,12 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 
	/*

	 * Go through the zonelist yet one more time, keep very high watermark

	 * here, this is only to catch a parallel oom killing, we must fail if

	 * we're still under heavy pressure.

	 * we're still under heavy pressure. But make sure that this reclaim

	 * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY

	 * allocation which will never fail due to oom_lock already held.

	 */

	page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order,

	page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &

				      ~__GFP_DIRECT_RECLAIM, order,

				      ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);

	if (page)

		goto out;