Commit 7d638093 authored Jun 10, 2015 by Vladimir Davydov Committed by Linus Torvalds Jun 10, 2015

memcg: do not call reclaim if !__GFP_WAIT



When trimming memcg consumption excess (see memory.high), we call
try_to_free_mem_cgroup_pages without checking if we are allowed to sleep
in the current context, which can result in a deadlock.  Fix this.

Fixes: 241994ed ("mm: memcontrol: default hierarchy interface for memory")
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 85bd8399

mm/memcontrol.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -2323,6 +2323,8 @@ done_restock:
		css_get_many(&memcg->css, batch);
		if (batch > nr_pages)
		refill_stock(memcg, batch - nr_pages);
		if (!(gfp_mask & __GFP_WAIT))
		goto done;
		/*
		* If the hierarchy is above the normal consumption range,
		* make the charging task trim their excess contribution.

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