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From: Tejun Heo <tj@kernel.org>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: Noah Feldt <noah@feldt.systems>,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
	N.Feldt@mittwald.de, carnil@debian.org, dschatzberg@meta.com,
	hannes@cmpxchg.org, peterz@infradead.org, stable@vger.kernel.org
Subject: Re: [PATCH v2] cgroup: Avoid iteration of dying tasks with zero refcount
Date: Fri, 11 Sep 2026 06:57:25 -1000	[thread overview]
Message-ID: <aqQy9UMKmXnKd934@slm.duckdns.org> (raw)
In-Reply-To: <aqQlowpkYrTaVmid@localhost.localdomain>

On Fri, Sep 11, 2026 at 06:11:42PM +0200, Michal Koutný wrote:
> On Tue, Sep 08, 2026 at 05:55:45PM +0200, Michal Koutný <mkoutny@suse.com> wrote:
> > Though, the fix loses a bit of elegance. Hm, thinking...
> 
> So, it occurs to me that the ->live based predicate from v2 might break
> CSS_TASK_ITER_WITH_DEAD callers (zombies they asked for would be
> skipped).
> We need to distinguish between (both on dying_tasks list):
> - regular zombies waiting to be reaped and
> - RCU remnant tasks that are going to be free'd.
> IIUC these two are split on the ->usage count. (Correct me if I'm
> wrong.)
> 
> I'm starting to like the tryget_task_struct() approach from v1 again.

Yeah, let's go back to v1. Sorry about the noise.

Thanks.

-- 
tejun

  reply	other threads:[~2026-09-11 16:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-07 19:27 Noah Feldt
2026-09-08 15:55 ` Michal Koutný
2026-09-11 16:11   ` Michal Koutný
2026-09-11 16:57     ` Tejun Heo [this message]
  -- strict thread matches above, loose matches on Subject: below --
2026-09-07 17:03 Michal Koutný
2026-09-07 17:07 ` Michal Koutný

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