From: Srivatsa Vaddagiri <vatsa@in.ibm.com>
To: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org, Myron Stowe <myron.stowe@hp.com>,
Jens Axboe <axboe@kernel.dk>, Dipankar <dipankar@in.ibm.com>,
Andrew Morton <akpm@osdl.org>, Gautham shenoy <ego@in.ibm.com>
Subject: Re: workqueue deadlock
Date: Thu, 7 Dec 2006 12:15:12 +0530 [thread overview]
Message-ID: <20061207064512.GA27583@in.ibm.com> (raw)
In-Reply-To: <20061207061701.GA25744@in.ibm.com>
On Thu, Dec 07, 2006 at 11:47:01AM +0530, Srivatsa Vaddagiri wrote:
> - Make it rw-sem
I think rw-sems also were shown to hit deadlocks (recursive read-lock
attempt deadlocks when a writer comes between the two read attempts by the same
thread). So below suggestion only seems to makes sense ..
> - Make it per-cpu mutex, which could be either:
>
> http://lkml.org/lkml/2006/11/30/110 - Ingo's suggestion
> http://lkml.org/lkml/2006/10/26/65 - Gautham's work based on RCU
>
> In Ingo's suggestion, I really dont know if the task_struct
> modifications is a good thing (to support recursive requirements).
> Gautham's patches avoid modifications to task_struct, is fast but can
> starve writers (who want to bring down/up a CPU).
--
Regards,
vatsa
next prev parent reply other threads:[~2006-12-07 6:45 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-07 0:26 workqueue deadlock Bjorn Helgaas
2006-12-07 6:17 ` Srivatsa Vaddagiri
2006-12-07 6:45 ` Srivatsa Vaddagiri [this message]
2006-12-07 18:51 ` Andrew Morton
2006-12-07 19:37 ` Andrew Morton
2006-12-08 2:53 ` Srivatsa Vaddagiri
2006-12-08 4:54 ` Andrew Morton
2006-12-08 7:58 ` Srivatsa Vaddagiri
2006-12-09 10:26 ` Ingo Molnar
2006-12-09 19:47 ` Andrew Morton
2006-12-10 8:26 ` Ingo Molnar
2006-12-10 8:43 ` Andrew Morton
2006-12-10 11:49 ` Ingo Molnar
2006-12-10 12:16 ` Andrew Morton
2006-12-10 12:19 ` Ingo Molnar
2006-12-10 12:34 ` Andrew Morton
2006-12-11 6:09 ` Ingo Molnar
2006-12-10 14:18 ` Rafael J. Wysocki
2006-12-11 6:52 ` Dipankar Sarma
2006-12-11 16:34 ` Rafael J. Wysocki
2006-12-11 5:45 ` Srivatsa Vaddagiri
2006-12-11 6:03 ` Andrew Morton
2006-12-11 4:58 ` Srivatsa Vaddagiri
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