From: Peter Zijlstra <peterz@infradead.org>
To: Ming Lei <tom.leiming@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Michael Wu <michael@allwinnertech.com>,
Xiaosen He <xiaosen.he@oss.qualcomm.com>,
Tejun Heo <tj@kernel.org>, Thomas Gleixner <tglx@kernel.org>
Subject: Re: [PATCH] sched: flush plug in schedule_preempt_disabled() to prevent deadlock
Date: Tue, 12 May 2026 18:49:47 +0200 [thread overview]
Message-ID: <20260512164947.GA2677887@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <agNLCof3zO5-QAo9@fedora>
On Tue, May 12, 2026 at 11:45:14PM +0800, Ming Lei wrote:
> > io_schedule()
> > token = io_schedule_prepare()
> > blk_flush_plug(current->plug, true);
> > schedule()
> > if (!task_is_running(tsk))
> > sched_submit_work()
> > blk_flush_plug(tsk->plug, true);
> >
> > Why isn't the one in sched_submit_work() sufficient? This thing either
> > needs a comment justifying its existence, or get removed.
> If io_schedule_prepare() can be called in every iowait context, looks
> blk_flush_plug() from sched_submit_work() may be removed.
No, the other way around. I don't see the point of having the one in
io_schedule_prepare(), since we'll hit the one in sched_submit_work().
next prev parent reply other threads:[~2026-05-12 16:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-12 8:59 [PATCH] sched: flush plug in schedule_preempt_disabled() to prevent deadlock Ming Lei
2026-05-12 12:04 ` Peter Zijlstra
2026-05-12 12:40 ` Peter Zijlstra
2026-05-12 15:45 ` Ming Lei
2026-05-12 16:49 ` Peter Zijlstra [this message]
2026-05-12 16:53 ` Peter Zijlstra
2026-05-12 17:16 ` Tejun Heo
2026-05-13 2:07 ` Ming Lei
2026-05-13 7:30 ` Peter Zijlstra
2026-05-13 8:08 ` Ming Lei
2026-05-15 6:18 ` Xiaosen
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