From mboxrd@z Thu Jan  1 00:00:00 1970
From: Clark Williams <williams@redhat.com>
Subject: Re: Tweak Latency on Intel ATOM
Date: Wed, 10 Feb 2010 16:38:18 -0600
Message-ID: <20100210163818.7f54ec3a@torg>
References: <loom.20100209T081421-234@post.gmane.org>
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Cc: linux-rt-users@vger.kernel.org
To: Max Miller <mxmr@gmx.net>
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On Tue, 9 Feb 2010 07:41:58 +0000 (UTC)
Max Miller <mxmr@gmx.net> wrote:

> Hello,
>=20
> im am using the PREEMPT-RT patch on linux 2.6.29.6. It runs on a MSI965GSE
> industial board with Intel ATOM CPU (N270, 1,6GHz) and i945GSE Northbridg=
e.=20
>=20
> I got about 45=B5s as maximum and 13=B5s as average latency when hyperthr=
eading is
> disabled. With enabled Hyperthreading the maximum latency increses to abo=
ut
> 100=B5s. I measured the latency with cyclictest.=20
>=20
> What can i do to get better maximum latency? Can I do somthing in the ker=
nel
> configuration or are there some kernel bootoptions? Or is it still imposs=
ible
> with this CPU to get better results?
>=20
> Thanks in advance,
> Max Miller=20
>=20
>

Make sure you turn off any power management settings in the BIOS and
turn off the irqbalance and cpuspeed services on the Linux side.

What cyclictest command are you using to measure latency?

Clark

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