linux-kernel - Re: [RFC 1/1] sched: Skip redundant operations for proxy tasks needing return migration

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADHxFxSiHJANrsXaOiSoUoBh8Z5Btrc4dRGHJwzLj4ebvy6ktg@mail.gmail.com>
Date: Wed, 11 Jun 2025 14:16:00 +0800
From: hupu <hupu.gm@...il.com>
To: John Stultz <jstultz@...gle.com>
Cc: peterz@...radead.org, linux-kernel@...r.kernel.org, juri.lelli@...hat.com, 
	vschneid@...hat.com, mingo@...hat.com, vincent.guittot@...aro.org, 
	dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com, 
	mgorman@...e.de, hupu@...nssion.com, Suleiman Souhlal <suleiman@...gle.com>
Subject: Re: [RFC 1/1] sched: Skip redundant operations for proxy tasks
 needing return migration

Hi John
Thank you for your response.

On Wed, Jun 11, 2025 at 1:05 PM John Stultz <jstultz@...gle.com> wrote:
>
> On Tue, Jun 10, 2025 at 7:32 PM hupu <hupu.gm@...il.com> wrote:
> >
> > Hi John,
> > It has been a few days without any response to this email. I'm
> > resending it for further discussion.
>
> Apologies, I'm swamped at the moment with some other items and haven't
> had time to give your suggestions enough serious thought to reply. :(
>
> I have made some slow progress on a few items. Suggested by Suleiman,
> I've reworked the migration logic to be considered after the owner
> on_rq check, so we avoid migrating tasks to only realize they are
> waiting on a sleeping owner and pulling them off the rq. This should
> help reduce the number of migrations we make.
>
> Unfortunately I've also been tripping over a crash with the full
> series (not the portion I'm currently submitting upstream) that often
> takes 30+ hours to reproduce and extra debugging logic seems to make
> it even harder to hit. With all the other tasks, keeping enough
> context in my head to make progress on this has been frustratingly
> slow.
>

If you'd like, I'd be happy to help investigate this crash issue. :)

To do that, I would need some additional information, such as the
vmlinux file, coredump, and the source code at the point where the
crash is triggered.

> I'll hopefully have something to share soon and I can
>

Look forward to hearing from you with good news.


Thanks.
hupu