Re: [PATCHSET] backing-dev: replace private thread pool with workqueue

From: Tejun Heo
Date: Tue Sep 07 2010 - 08:36:27 EST


Hello,

On 09/07/2010 02:29 PM, Jens Axboe wrote:
> I agree (with both of you). It's definitely too early to convert it
> over, but if we can in the longer run, it never hurts to get rid of
> code. The writeback threads aren't a typical threadpool, in that the
> threads stick around and only go away when idle for too long. If they
> stick around, you get the same process hammering IO at your device. So
> converting that over to the generic cwq may or may not be at a
> performance cost, it'll definitely have to be tested.

One thing to try is removing WQ_UNBOUND and see how it affects the
performance. I put WQ_UNBOUND there mainly to keep the behavior about
the same as the current code but given what it does I think it would
probably fare better with workers bound to CPUs.

Thanks.

--
tejun
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