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Date: Thu, 28 May 2015 12:59:34 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Vladimir Davydov <vdavydov@parallels.com>
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.cz>
Subject: Re: [PATCH] memcg: do not call reclaim if !__GFP_WAIT
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On Thu, 28 May 2015 20:26:06 +0300 Vladimir Davydov <vdavydov@parallels.com> wrote:

> 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.

Why does it deadlock?  try_to_free_mem_cgroup_pages() is passed the
gfp_mask and should honour its __GFP_WAIT setting?