From: Florian Mickler <florian@mickler.org>
To: James Bottomley <James.Bottomley@suse.de>
Cc: pm list <linux-pm@lists.linux-foundation.org>,
markgross@thegnar.org, mgross@linux.intel.com,
linville@tuxdriver.com, Frederic Weisbecker <fweisbec@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] pm_qos: make update_request non blocking
Date: Wed, 9 Jun 2010 18:00:33 +0200 [thread overview]
Message-ID: <20100609180033.39d5b499@schatten.dmk.lab> (raw)
In-Reply-To: <1276097832.4343.223.camel@mulgrave.site>
On Wed, 09 Jun 2010 11:37:12 -0400
James Bottomley <James.Bottomley@suse.de> wrote:
> This still isn't resilient against two successive calls to update. If
> the second one gets to schedule_work() before the work of the first one
> has finished, you'll corrupt the workqueue.
Sorry, I don't see it. Can you elaborate?
In "run_workqueue(" we do a list_del_init() which resets the
list-pointers of the workitem and only after that reset the
WORK_STRUCT_PENDING member of said structure.
schedule_work does a queue_work_on which does a test_and_set_bit on
the WORK_STRUCT_PENDING member of the work and only queues the work
via list_add_tail in insert_work afterwards.
Where is my think'o? Or was this fixed while you didn't look?
So what _can_ happen, is that we miss a new notfication while the old
notification is still in the queue. But I don't think this is a problem.
Cheers,
Flo
next prev parent reply other threads:[~2010-06-09 16:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-09 15:29 [PATCH v4] pm_qos: make update_request non blocking florian
2010-06-09 15:37 ` James Bottomley
2010-06-09 16:00 ` Florian Mickler [this message]
2010-06-09 16:07 ` James Bottomley
2010-06-09 16:32 ` Florian Mickler
2010-06-09 17:05 ` James Bottomley
2010-06-09 17:31 ` Florian Mickler
2010-06-10 7:45 ` Florian Mickler
2010-06-10 13:39 ` [linux-pm] " James Bottomley
2010-06-10 14:41 ` Florian Mickler
2010-06-11 14:25 ` James Bottomley
2010-06-11 15:49 ` Florian Mickler
2010-06-14 14:33 ` Florian Mickler
2010-06-14 14:44 ` James Bottomley
2010-06-14 14:49 ` Florian Mickler
2010-06-14 15:10 ` James Bottomley
2010-06-14 15:20 ` Florian Mickler
[not found] ` <1276526800-12362-3-git-send-email-florian@mickler.org>
2010-06-15 17:23 ` [PATCH 3/3] pm_qos: only schedule work when in interrupt context Florian Mickler
2010-06-17 23:02 ` James Bottomley
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