From: Tejun Heo <tj@kernel.org>
To: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Toshi Kani <toshi.kani@hp.com>,
LKML <linux-kernel@vger.kernel.org>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Subject: Re: [PATCH] driver core / ACPI: Avoid device removal locking problems
Date: Tue, 27 Aug 2013 14:36:44 -0400 [thread overview]
Message-ID: <20130827183644.GC12212@mtj.dyndns.org> (raw)
In-Reply-To: <521C6FA8.4070804@cn.fujitsu.com>
Hello,
On Tue, Aug 27, 2013 at 05:21:44PM +0800, Gu Zheng wrote:
> >> OK, so the patch below is quick and dirty and overkill, but it should make the
> >> splat go away at least.
> >
> > And if this patch does make the splat go away for you, please also test the
> > appended one (Tejun, thanks for the hint!).
> >
> > I'll address the ACPI part differently later.
>
> What about changing device_hotplug_lock and acpi_scan_lock to rwsem? like the
> attached one(With a preliminary test, it also can make the splat go away).:)
Hmmm.. I don't get it. How is introducing another rwlock whic may
cause the operation, even reading the status, to fail randomly a
better option? It's harier and more brittle. We probably want to
implement better solution in sysfs for files which interact with
device addition / removal paths but for now I think Rafael's patch is
the right direction.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-08-27 18:36 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-25 20:09 [PATCH] driver core / ACPI: Avoid device removal locking problems Rafael J. Wysocki
2013-08-25 21:54 ` Greg Kroah-Hartman
2013-08-26 3:13 ` Gu Zheng
2013-08-26 12:42 ` Rafael J. Wysocki
2013-08-26 14:43 ` Rafael J. Wysocki
2013-08-26 15:02 ` Rafael J. Wysocki
2013-08-27 3:26 ` Gu Zheng
2013-08-27 9:21 ` Gu Zheng
2013-08-27 18:36 ` Tejun Heo [this message]
2013-08-27 21:45 ` Rafael J. Wysocki
2013-08-28 10:03 ` Gu Zheng
2013-08-28 12:24 ` Tejun Heo
2013-08-28 13:24 ` Rafael J. Wysocki
2013-08-28 13:45 ` [PATCH 0/2] " Rafael J. Wysocki
2013-08-28 13:48 ` [PATCH 1/2] driver core / ACPI: Avoid device hot remove locking issues Rafael J. Wysocki
2013-08-28 18:53 ` Greg Kroah-Hartman
2013-08-29 2:02 ` Gu Zheng
2013-08-28 13:51 ` [PATCH 2/2] ACPI / hotplug: Remove containers synchronously Rafael J. Wysocki
2013-08-28 18:53 ` Greg Kroah-Hartman
2013-08-29 2:02 ` Gu Zheng
2013-08-28 17:06 ` [PATCH 0/2] driver core / ACPI: Avoid device removal locking problems Toshi Kani
2013-08-29 2:00 ` Gu Zheng
2013-08-27 21:38 ` [PATCH] " Toshi Kani
2013-08-28 2:12 ` Gu Zheng
2013-08-28 16:55 ` Toshi Kani
2013-08-27 2:03 ` Gu Zheng
2013-08-27 2:38 ` Gu Zheng
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