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Subject: Re: it821x eats CPU?
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Heinz Ulrich Stille <hus@design-d.de>
Cc: linux-kernel@vger.kernel.org
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Date: Wed, 11 Oct 2006 20:13:41 +0100
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Ar Sad, 2006-10-07 am 09:27 +0200, ysgrifennodd Heinz Ulrich Stille:
> Looking through the logs I notices that it821x was in "smart" mode,
> so I restarted the system with "noraid=1" to get into "pass through".
> Now everything is back to normal. A large dd did about 40MB/s without
> disturbing other processes.

In some configurations the it821x driver was not enabling DMA in smart
mode.

> Wasn't smart mode the one supposed to be the one reducing CPU load?

For RAID1 yes, otherwise not measurably at all.