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From: Thomas Gleixner <tglx@linutronix.de>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Jiakai Xu <xujiakai24@mails.ucas.ac.cn>
Cc: Ingo Molnar <mingo@redhat.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Valentin Schneider <vschneid@redhat.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/mmcid: Bound the CID allocation busy wait
Date: Fri, 13 Nov 2026 15:32:09 +0100	[thread overview]
Message-ID: <87eccossye.ffs@fw13> (raw)
In-Reply-To: <bd4c03e6-7ea6-4a21-9a3e-74ea9d36fe17@efficios.com>

On Wed, Nov 11 2026 at 20:48, Mathieu Desnoyers wrote:
> On Tue, Oct 20 2026 at 15:54, Thomas Gleixner wrote:
> I have a reproducer for a lockup that starts from the stale state you
> describe. It needs two more things: the execve() fails, and the task is
> moved to another CPU during that execve().

That has been reported already privately to me and a few others and the
reporter provided a similar patch as you.

While both variants seem simpler, I prefer the explicit
re-initialization for the failed exec() case.

It's a NOOP for newly initialized MMs and avoids the pointless fixup
dance for the last user in the common case.

Thanks,

        tglx

      reply	other threads:[~2026-11-13 14:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-18  1:34 [PATCH] sched/mmcid: Bound the CID allocation busy wait Jiakai Xu
2026-09-18 10:43 ` Peter Zijlstra
2026-10-15 20:37   ` Thomas Gleixner
2026-10-20 13:54     ` Thomas Gleixner
2026-10-21  1:30       ` Jiakai Xu
2026-11-12  1:48       ` Mathieu Desnoyers
2026-11-13 14:32         ` Thomas Gleixner [this message]

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