From: Nam Cao <namcao@linutronix.de>
To: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>,
Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>,
Helge Deller <deller@gmx.de>,
Thomas Zimmermann <tzimmermann@suse.de>,
Daniel Vetter <daniel@ffwll.ch>,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
bigeasy@linutronix.de, LKML <linux-kernel@vger.kernel.org>,
Vegard Nossum <vegard.nossum@oracle.com>,
George Kennedy <george.kennedy@oracle.com>,
Darren Kenny <darren.kenny@oracle.com>,
chuansheng.liu@intel.com
Subject: Re: [bug-report] task info hung problem in fb_deferred_io_work()
Date: Fri, 19 Apr 2024 17:34:43 +0200 [thread overview]
Message-ID: <20240419173443.6c49706e@namcao> (raw)
In-Reply-To: <CAMeQTsbEjUyOYDAF-kFwTcovLr+8gHQGa27jPkeeJqmLhwbTag@mail.gmail.com>
On 2024-04-19 Patrik Jakobsson wrote:
> Neither cancel_delayed_work_sync() or flush_delayed_work() prevent new
> work from being scheduled after they return.
flush_delayed_work() is called during device closing. And because no
writes are performed after the device has been closed, no new work
should be queued after flush_delayed_work().
> But
> cancel_delayed_work_sync() at least makes sure the queue is empty so
> the problem becomes less apparent.
>
> Could this explain what we're seeing?
I suspect that cancel_delayed_work_sync() is only treating the symptoms
by preventing the deferred work from running. The real bug is "someone"
giving fb_deferred_io_work() invalid pages to work with. But that's
just a blind guess.
Best regards,
Nam
next prev parent reply other threads:[~2024-04-19 15:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 12:39 [bug-report] task info hung problem in fb_deferred_io_work() Harshit Mogalapalli
2024-04-18 13:14 ` Patrik Jakobsson
2024-04-18 14:05 ` Nam Cao
2024-04-18 14:34 ` Patrik Jakobsson
2024-04-19 15:18 ` Nam Cao
2024-04-19 7:27 ` Harshit Mogalapalli
2024-04-18 14:06 ` Nam Cao
2024-04-18 14:26 ` Takashi Iwai
2024-04-18 19:29 ` Helge Deller
2024-04-19 6:44 ` Takashi Iwai
2024-04-19 7:39 ` Harshit Mogalapalli
2024-04-19 7:45 ` Takashi Iwai
2024-04-19 7:50 ` Patrik Jakobsson
2024-04-19 15:34 ` Nam Cao [this message]
2024-04-30 11:45 ` Patrik Jakobsson
2024-04-19 14:42 ` Harshit Mogalapalli
2024-04-19 7:35 ` Harshit Mogalapalli
2024-04-19 14:59 ` Nam Cao
2024-04-19 16:05 ` Harshit Mogalapalli
2024-04-19 16:23 ` Nam Cao
2024-04-19 16:39 ` Harshit Mogalapalli
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