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Date:   Tue, 22 Mar 2022 16:22:16 +0100
Message-ID: <s5ha6dixb9z.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc:     LKML <linux-kernel@vger.kernel.org>, Tejun Heo <tj@kernel.org>,
        Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: An announcement for kernel-global workqueue users.
In-Reply-To: <49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp>
References: <49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp>
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On Mon, 21 Mar 2022 02:24:23 +0100,
Tetsuo Handa wrote:
> 
> Hello.
> 
> The Linux kernel provides kernel-global WQs (namely, system_wq, system_highpri_wq,
> system_long_wq, system_unbound_wq, system_freezable_wq, system_power_efficient_wq
> and system_freezable_power_efficient_wq). But since attempt to flush kernel-global
> WQs has possibility of deadlock, Tejun Heo thinks that we should stop calling
> flush_scheduled_work() and flush_workqueue(system_*). Such callers as of Linux 5.17
> are listed below.
> 
> ----------
> $ git grep -nF 'flush_scheduled_work()'
(snip)
> sound/soc/intel/atom/sst/sst.c:363:     flush_scheduled_work();

At least this one looks superfluous, the call can be simply dropped.
I'm going to submit a fix patch.


thanks,

Takashi