Re: request baset device mapper in Linux

From: Lukas Hejtmanek
Date: Thu Sep 08 2011 - 09:47:22 EST


On Mon, Aug 01, 2011 at 06:31:02PM +0900, Kiyoshi Ueda wrote:
> Hi Lukas,
>
> Lukas Hejtmanek wrote:
> > On Sat, Jul 23, 2011 at 04:28:06PM +0900, Jun'ichi Nomura wrote:
> >> As Kiyoshi suggested, it is important to know whether this
> >> problem occurs with the latest kernel.
> >> So if you could try 3.0, it would be very helpful.
> >
> > so, do I need to check recent kernel as the patch works for me?
>
> Yes, please.
> (Unfortunately my storage has been broken today :-<)
>
> CPU usage seems to be one of the reasons for your case, but I
> still cannot understand why memory pressure is needed.
> I want to know your problem also occurs on 3.0 without the patch.

Well, I tried 3.0.3 kernel. It is not so bad as 2.6.32.36, but it is not as
good as the same kernel with your patch.

CPU load is caused by ksoftirqd (30-40%) and kworker (30%).

Overal speed is about 2.5GB/s. With your patch I can reach 2.8-2.9GB/s.

--
Lukáš Hejtmánek
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