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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2017-08-31 16:15:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-08-31 16:33:14 -0700
commite746bf730a76fe53b82c9e6b6da72d58e9ae3565 (patch)
tree5d0170fe8a0bbfbbf4940a2c452ce0f505d14ade
parent42ff72cf27027fa28dd79acabe01d9196f1480a7 (diff)
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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/page_alloc.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7a58eb5757e3..1423da8dd16f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3291,10 +3291,13 @@ __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,
- ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
+ page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
+ ~__GFP_DIRECT_RECLAIM, order,
+ ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
if (page)
goto out;