Date:   Thu, 9 Dec 2021 08:51:54 +0100
From:   Michal Hocko <mhocko@suse.com>
To:     Joel Savitz <jsavitz@redhat.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Waiman Long <longman@redhat.com>, linux-mm@kvack.org,
        Nico Pache <npache@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Darren Hart <dvhart@infradead.org>,
        Davidlohr Bueso <dave@stgolabs.net>,
        =?iso-8859-1?Q?Andr=E9?= Almeida <andrealmeid@collabora.com>
Subject: Re: [PATCH] mm/oom_kill: wake futex waiters before annihilating
 victim shared mutex
Message-ID: <YbG1mu0CLONo+Z7l@dhcp22.suse.cz>
References: <20211207214902.772614-1-jsavitz@redhat.com>
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On Wed 08-12-21 21:59:29, Joel Savitz wrote:
> On Wed, Dec 8, 2021 at 11:05 AM Michal Hocko <mhocko@suse.com> wrote:
[...]
> > I have had a closer look and I guess I can see what you are trying to
> > achieve. futex_exit_release is normally called from exit_mm context. You
> > are likely seeing a situation when the oom victim is blocked and cannot
> > exit. That is certainly possible but it shouldn't be a permanent state.
> > So I would be more interested about your particular issue and how long
> > the task has been stuck unable to exit.
> 
> Before applying this patch I never saw a task eventually exit during
> the reproduction of this system state.

What has happened to the oom victim and why it has never exited?

Side note. I have noticed that you have sent v2 with minor changes. It
is usualy better to resolve review feedback before posting a new
version. Discussion gets rather hard to follow otherwise.

Thanks!
-- 
Michal Hocko
SUSE Labs