Re: [PATCH] mm: memcontrol: reset memory.low on css offline

From: Tejun Heo
Date: Mon Feb 29 2016 - 15:55:21 EST


On Mon, Feb 29, 2016 at 03:02:55PM -0500, Johannes Weiner wrote:
> > To fix this, let's reset memory.low on css offline.
> We already have mem_cgroup_css_reset() for soft-offlining a css - when
> the css is asked to be disabled but another subsystem still uses it.
> Can we just call that function during offline as well? The css can be
> around for quite a bit after the user deleted it. Eliminating *any*
> user-supplied configurations and zapping it back to defaults makes
> sense in general, so that we never have to worry about any remnants.

Hmmm... I wonder whether the behavior can be a bit surprising and it
could be better to simply let memcg offline callback to call the reset
function explicitly. No big deal either way tho. Please feel free to
send a patch.