From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Subject: Re: [patch v2] mm, memcg: do not retry precharge charges
Date: Sat, 14 Jan 2017 11:22:38 -0500
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To: David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Vladimir Davydov <vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org

On Fri, Jan 13, 2017 at 02:09:53AM -0800, David Rientjes wrote:
> When memory.move_charge_at_immigrate is enabled and precharges are
> depleted during move, mem_cgroup_move_charge_pte_range() will attempt to
> increase the size of the precharge.
> 
> Prevent precharges from ever looping by setting __GFP_NORETRY.  This was
> probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is
> pointless as written.

The OOM killer livelock was the motivation for this patch. With that
ruled out, what's the point of this patch? Try a bit less hard to move
charges during task migration?