Re: [PATCH 7/7] ondemand: Solve the big performance issue withondemand during disk IO

From: Arjan van de Ven
Date: Fri Apr 23 2010 - 09:51:12 EST


On Fri, 23 Apr 2010 07:24:39 +0200
Pavel Machek <pavel@xxxxxx> wrote:

>
> Well, and now, if you do something like cat /dev/<your usb1.1 hdd> >
> /dev/null, you'll keep cpu on max frequency. Not a problem for new
> core i7, but probably big deal for athlon 64.

do you have facts not speculation for this? Does the athlon 64 really
keep its voltage high during idle? That would surprise me greatly...
(and if it does, does it matter? the clock is stopped anyway there)

the only place where my patch makes a real difference is when the cpu
is idle due to blocking IO! So do you have data that the athlon 64 gets
too hot if you select a high frequency during an idle period, where the
clock is already stopped?



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Arjan van de Ven Intel Open Source Technology Centre
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