From: Oleg Nesterov <oleg@redhat.com>
To: "Arve Hjønnevåg" <arve@android.com>
Cc: Tejun Heo <tj@kernel.org>,
linux-pm@lists.linux-foundation.org,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Dmitri Vorobiev <dmitri.vorobiev@movial.com>,
Jiri Kosina <jkosina@suse.cz>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 7/9] PM: Add suspend blocking work.
Date: Mon, 26 Apr 2010 16:06:03 +0200 [thread overview]
Message-ID: <20100426140603.GA5702@redhat.com> (raw)
In-Reply-To: <y2ud6200be21004231549q8e52c9c0z441d82b5a15e177d@mail.gmail.com>
On 04/23, Arve Hjønnevåg wrote:
>
> On Fri, Apr 23, 2010 at 5:20 AM, Oleg Nesterov <oleg@redhat.com> wrote:
>
> > The unblock code in run_workqueue() is racy,
> > it can unblock after the work was queued on another CPU, cwq->lock can't
> > help.
>
> If the work is both queued and starts running on another workqueue
> between "get_wq_data(work) == cwq" and "!work_pending(work)", then
> suspend_unblock will be called when it shouldn't. It should work fine
> if I change to it check pending first though, since it cannot move
> back to the current workqueue without locking cwq->lock first.
It can be queued on the same or different workqueue on another CPU,
right before run_workqueue() does unblock.
But I guess this doesn't matter. You already discussed this all with
Tejun while I was sleeping ;) And I agree very much, the new plan looks
much better imho.
Oleg.
next prev parent reply other threads:[~2010-04-26 14:08 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 1:08 [PATCH 0/9] Suspend block api (version 4) Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 1/9] PM: Add suspend block api Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 2/9] PM: suspend_block: Add driver to access suspend blockers from user-space Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 3/9] PM: suspend_block: Abort task freezing if a suspend_blocker is active Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 4/9] PM: suspend_block: Switch to list of active and inactive suspend blockers Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 5/9] PM: suspend_block: Add debugfs file Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 6/9] PM: suspend_block: Add suspend_blocker stats Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 7/9] PM: Add suspend blocking work Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 8/9] Input: Block suspend while event queue is not empty Arve Hjønnevåg
2010-04-23 1:08 ` [PATCH 9/9] power_supply: Block suspend while power supply change notifications are pending Arve Hjønnevåg
2010-04-23 20:56 ` [PATCH 8/9] Input: Block suspend while event queue is not empty Randy Dunlap
2010-04-23 21:08 ` Dmitry Torokhov
2010-04-24 5:02 ` Arve Hjønnevåg
2010-04-24 14:36 ` [linux-pm] " Alan Stern
2010-04-25 2:30 ` Rafael J. Wysocki
2010-04-25 15:29 ` Alan Stern
2010-04-25 22:41 ` Arve Hjønnevåg
2010-04-24 4:58 ` Arve Hjønnevåg
2010-04-23 8:16 ` [PATCH 7/9] PM: Add suspend blocking work Tejun Heo
2010-04-23 12:20 ` Oleg Nesterov
2010-04-23 22:49 ` Arve Hjønnevåg
2010-04-24 5:21 ` Arve Hjønnevåg
2010-04-24 6:33 ` Tejun Heo
2010-04-24 7:21 ` Arve Hjønnevåg
2010-04-24 7:43 ` Tejun Heo
2010-04-26 14:06 ` Oleg Nesterov [this message]
2010-04-23 20:58 ` [PATCH 5/9] PM: suspend_block: Add debugfs file Randy Dunlap
2010-04-24 3:23 ` Arve Hjønnevåg
2010-04-24 4:24 ` Randy Dunlap
2010-04-24 4:54 ` Arve Hjønnevåg
2010-04-25 18:15 ` Greg KH
2010-04-25 19:53 ` Randy Dunlap
2010-04-26 0:00 ` tytso
2010-04-26 0:23 ` Randy Dunlap
2010-04-26 0:45 ` tytso
2010-04-26 0:50 ` Randy Dunlap
2010-04-26 1:39 ` [linux-pm] " Alan Stern
2010-04-26 6:24 ` Brian Swetland
2010-04-26 13:28 ` Randy Dunlap
2010-04-23 2:25 ` [linux-pm] [PATCH 2/9] PM: suspend_block: Add driver to access suspend blockers from user-space Matt Helsley
2010-04-23 3:54 ` Arve Hjønnevåg
2010-04-23 4:38 ` Greg KH
2010-04-23 8:43 ` Pavel Machek
2010-04-23 16:43 ` [linux-pm] " Alan Stern
2010-04-24 3:20 ` Arve Hjønnevåg
2010-04-24 5:55 ` Pavel Machek
2010-04-24 14:44 ` Alan Stern
2010-04-25 22:34 ` Arve Hjønnevåg
2010-04-26 19:25 ` Alan Stern
2010-04-27 4:04 ` Arve Hjønnevåg
2010-04-27 18:33 ` Alan Stern
2010-04-27 22:03 ` Rafael J. Wysocki
2010-04-27 23:22 ` Arve Hjønnevåg
2010-04-24 1:53 ` tytso
2010-04-24 5:39 ` Pavel Machek
2010-04-23 16:33 ` [PATCH 1/9] PM: Add suspend block api Alan Stern
2010-04-23 16:45 ` [linux-pm] " Alan Stern
2010-04-24 2:15 ` Arve Hjønnevåg
2010-04-24 2:30 ` Alan Stern
2010-04-24 3:14 ` Arve Hjønnevåg
2010-04-23 4:39 ` [linux-pm] [PATCH 0/9] Suspend block api (version 4) Greg KH
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