From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michal Hocko <mhocko-IBi9RG/b67k@public.gmane.org>
Subject: Re: [PATCH v5 2/6] mm/memcg: Disable threshold event handlers on
 PREEMPT_RT
Date: Thu, 2 Mar 2023 12:24:27 +0100
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To: Valentin Schneider <vschneid-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Sebastian Andrzej Siewior <bigeasy-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny-IBi9RG/b67k@public.gmane.org>, Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Vladimir Davydov <vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>, Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

On Thu 02-03-23 10:18:31, Valentin Schneider wrote:
> On 02/03/23 08:45, Michal Hocko wrote:
> > On Wed 01-03-23 18:23:19, Valentin Schneider wrote:
[...]
> >> I want cgroupv1 to die as much as the next person, but in that specific
> >> situation I kinda need cgroupv1 to behave somewhat sanely on RT with
> >> threshold events :/
> >
> > Could you expand on the usecase?
> >
> 
> In this case it's just some middleware leveraging memcontrol cgroups and
> setting up callbacks for in-cgroup OOM events. This is a supported feature
> in cgroupv2, so this isn't a problem of cgroupv1 vs cgroupv2 feature
> parity, but rather one of being in a transitional phase where the
> middleware itself hasn't fully migrated to using cgroupv2.

How is this related to the RT kernel config? memcg OOM vs any RT
assumptions do not really get along well AFAICT.

-- 
Michal Hocko
SUSE Labs