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Date: Fri, 20 Dec 2013 11:53:59 -0500
From: Luiz Capitulino <lcapitulino@redhat.com>
To: Glauber Costa <glommer@gmail.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>, dchinner@redhat.com,
        Michal Hocko <mhocko@suse.cz>, Johannes Weiner <hannes@cmpxchg.org>,
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        Glauber Costa <glommer@openvz.org>,
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        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [PATCH v14 16/18] vmpressure: in-kernel notifications
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On Fri, 20 Dec 2013 20:46:05 +0400
Glauber Costa <glommer@gmail.com> wrote:

> On Fri, Dec 20, 2013 at 8:44 PM, Luiz Capitulino <lcapitulino@redhat.com> wrote:
> > On Fri, 20 Dec 2013 10:03:32 -0500
> > Luiz Capitulino <lcapitulino@redhat.com> wrote:
> >
> >> > The answer for all of your questions above can be summarized by noting
> >> > that for the lack of other users (at the time), this patch does the bare minimum
> >> > for memcg needs. I agree, for instance, that it would be good to pass the level
> >> > but since memcg won't do anything with thta, I didn't pass it.
> >> >
> >> > That should be extended if you need to.
> >>
> >> That works for me. That is, including this minimal version first and
> >> extending it when we get in-tree users.
> >
> > Btw, there's something I was thinking just right now. If/when we
> > convert shrink functions to use this API, they will come to depend
> > on CONFIG_MEMCG=y. IOW, they won't work if CONFIG_MEMCG=n.
> >
> > Is this acceptable (this is an honest question)? Because today, they
> > do work when CONFIG_MEMCG=n. Should those shrink functions use the
> > shrinker API as a fallback?
> 
> If you have a non-memcg user, that should obviously be available for
> CONFIG_MEMCG=n

OK, which means we'll have to change it, right? Because, if I'm not
missing something, today vmpressure does depend on CONFIG_MEMCG=y.