From: Nico Pache <npache@redhat.com>
To: Michal Hocko <mhocko@suse.com>, Davidlohr Bueso <dave@stgolabs.net>
Cc: linux-mm@kvack.org, Andrea Arcangeli <aarcange@redhat.com>,
Joel Savitz <jsavitz@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Rafael Aquini <aquini@redhat.com>,
Waiman Long <longman@redhat.com>, Baoquan He <bhe@redhat.com>,
Christoph von Recklinghausen <crecklin@redhat.com>,
Don Dutile <ddutile@redhat.com>,
"Herton R . Krzesinski" <herton@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Darren Hart <dvhart@infradead.org>,
Andre Almeida <andrealmeid@collabora.com>,
David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v5] mm/oom_kill.c: futex: Close a race between do_exit and the oom_reaper
Date: Mon, 21 Mar 2022 19:53:29 -0600 [thread overview]
Message-ID: <c8bb0b6d-981c-8591-d5b6-17414c934758@redhat.com> (raw)
In-Reply-To: <20220322004231.rwmnbjpq4ms6fnbi@offworld>
On 3/21/22 18:42, Davidlohr Bueso wrote:
> On Mon, 21 Mar 2022, Michal Hocko wrote:
>
>> The more I am thinking about this the more I am getting convinced that
>> we should rather approach this differently and skip over vmas which can
>> be holding the list. Have you considered this option?
>
> While I tend to agree with this over a hacky trylock approach, I cannot
> help but think that v3 was the right thing to do, at least conceptually.
Yeah conceptually the V3 was the first correct patch. It could use some slight
cleanup with a wrapper like in this v5 (has_robust_list), and instead of
returning it should set MMF_OOM_SKIP.
> Robust futex users here care enough about dealing with crashes while holding
> a lock that they sacrifice the performance of regular futexes. So the OOM
> killer should not cause this very thing. I went through previous threads
> but other than the user base (which I don't think would be very large
> just because of the performance implications), was there any other reason
> to no just set MMF_OOM_SKIP upon a robust list?
We could proceed with the V3 approach; however if we are able to find a complete
solution that keeps both functionalities (Concurrent OOM Reaping & Robust Futex)
working, I dont see why we wouldnt go for it.
If we can't find a good/reliable way to check if the vma contains the robust
list then I think we should just skip the OOM like in the v3.
Cheers,
-- Nico
>
> Thanks,
> Davidlohr
>
next prev parent reply other threads:[~2022-03-22 1:53 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-18 3:36 [PATCH v5] mm/oom_kill.c: futex: Close a race between do_exit and the oom_reaper Nico Pache
2022-03-21 8:55 ` Michal Hocko
2022-03-21 22:45 ` Nico Pache
2022-03-22 0:42 ` Davidlohr Bueso
2022-03-22 1:53 ` Nico Pache [this message]
2022-03-22 2:57 ` Davidlohr Bueso
2022-03-22 3:09 ` Nico Pache
2022-03-22 8:26 ` Michal Hocko
2022-03-22 15:17 ` Thomas Gleixner
2022-03-22 16:36 ` Michal Hocko
2022-03-22 22:43 ` Thomas Gleixner
2022-03-23 9:17 ` Michal Hocko
2022-03-23 10:30 ` Thomas Gleixner
2022-03-23 11:11 ` Peter Zijlstra
2022-03-30 9:18 ` Michal Hocko
2022-03-30 18:18 ` Nico Pache
2022-03-30 21:36 ` Nico Pache
2022-04-06 17:22 ` Nico Pache
2022-04-06 17:36 ` Nico Pache
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c8bb0b6d-981c-8591-d5b6-17414c934758@redhat.com \
--to=npache@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andrealmeid@collabora.com \
--cc=aquini@redhat.com \
--cc=bhe@redhat.com \
--cc=crecklin@redhat.com \
--cc=dave@stgolabs.net \
--cc=ddutile@redhat.com \
--cc=dvhart@infradead.org \
--cc=herton@redhat.com \
--cc=jsavitz@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=longman@redhat.com \
--cc=mhocko@suse.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rientjes@google.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.