From: Peter Zijlstra <peterz@infradead.org>
To: Julian Sun <sunjunchao@bytedance.com>
Cc: cgroups@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk,
brauner@kernel.org, jack@suse.cz, mingo@redhat.com,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, vschneid@redhat.com,
akpm@linux-foundation.org, lance.yang@linux.dev,
mhiramat@kernel.org, agruenba@redhat.com, hannes@cmpxchg.org,
mhocko@kernel.org, roman.gushchin@linux.dev,
shakeel.butt@linux.dev, muchun.song@linux.dev
Subject: Re: [PATCH 0/3] Suppress undesirable hung task warnings.
Date: Mon, 22 Sep 2025 15:27:18 +0200 [thread overview]
Message-ID: <20250922132718.GB49638@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20250922094146.708272-1-sunjunchao@bytedance.com>
On Mon, Sep 22, 2025 at 05:41:43PM +0800, Julian Sun wrote:
> As suggested by Andrew Morton in [1], we need a general mechanism
> that allows the hung task detector to ignore unnecessary hung
> tasks. This patch set implements this functionality.
>
> Patch 1 introduces a PF_DONT_HUNG flag. The hung task detector will
> ignores all tasks that have the PF_DONT_HUNG flag set.
>
> Patch 2 introduces wait_event_no_hung() and wb_wait_for_completion_no_hung(),
> which enable the hung task detector to ignore hung tasks caused by these
> wait events.
>
> Patch 3 uses wb_wait_for_completion_no_hung() in the final phase of memcg
> teardown to eliminate the hung task warning.
>
> Julian Sun (3):
> sched: Introduce a new flag PF_DONT_HUNG.
> writeback: Introduce wb_wait_for_completion_no_hung().
> memcg: Don't trigger hung task when memcg is releasing.
This is all quite terrible. I'm not at all sure why a task that is
genuinely not making progress and isn't killable should not be reported.
next prev parent reply other threads:[~2025-09-22 13:27 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-22 9:41 [PATCH 0/3] Suppress undesirable hung task warnings Julian Sun
2025-09-22 9:41 ` [PATCH 1/3] sched: Introduce a new flag PF_DONT_HUNG Julian Sun
2025-09-22 9:41 ` [PATCH 2/3] writeback: Introduce wb_wait_for_completion_no_hung() Julian Sun
2025-09-22 9:41 ` [PATCH 3/3] memcg: Don't trigger hung task warnings when memcg is releasing resources Julian Sun
2025-09-22 11:38 ` [PATCH 0/3] Suppress undesirable hung task warnings Lance Yang
2025-09-22 12:40 ` Julian Sun
2025-09-22 13:12 ` Lance Yang
2025-09-22 21:57 ` Andrew Morton
2025-09-23 2:30 ` Lance Yang
2025-09-23 2:45 ` [External] " Julian Sun
2025-09-23 3:18 ` Lance Yang
2025-09-22 13:07 ` Michal Hocko
2025-09-22 14:24 ` [External] " Julian Sun
2025-09-22 13:27 ` Peter Zijlstra [this message]
2025-09-22 14:29 ` Julian Sun
2025-09-22 15:27 ` Jan Kara
2025-09-22 18:08 ` Christoph Hellwig
2025-09-22 21:50 ` Andrew Morton
2025-09-23 7:16 ` Peter Zijlstra
2025-09-23 12:44 ` Masami Hiramatsu
2025-09-24 10:34 ` Jan Kara
2025-09-25 15:07 ` [External] " Julian Sun
2025-09-25 16:30 ` Jan Kara
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