The patch titled
Subject: mm,page_alloc: don't call __node_reclaim() with oom_lock held.
has been added to the -mm tree. Its filename is
mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held.patch
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------------------------------------------------------
From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Subject: mm,page_alloc: don't call __node_reclaim() with oom_lock held.
We are doing 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@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff -puN mm/page_alloc.c~mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held mm/page_alloc.c
--- a/mm/page_alloc.c~mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held
+++ a/mm/page_alloc.c
@@ -3291,10 +3291,13 @@ __alloc_pages_may_oom(gfp_t gfp_mask, un
/*
* 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;
_
Patches currently in -mm which might be from penguin-kernel@xxxxxxxxxxxxxxxxxxx are
mmpage_alloc-dont-call-__node_reclaim-with-oom_lock-held.patch
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