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; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
