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Subject: Re: [PATCH 3/4] new timeofday x86-64 arch specific changes (v. B1)
From: john stultz <johnstul@us.ibm.com>
To: Parag Warudkar <kernel-stuff@comcast.net>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>, Andi Kleen <ak@suse.de>,
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Date: Thu, 02 Jun 2005 16:20:53 -0700
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On Thu, 2005-06-02 at 19:05 -0400, Parag Warudkar wrote:
> On Thursday 02 June 2005 14:39, Nishanth Aravamudan wrote:
> > Which timesource is being used?
> >
> > cat /sys/devices/system/timesource/timesource0/timesource
> 
> tux-gentoo parag # cat /sys/devices/system/timesource/timesource0/timesource
> jiffies tsc tsc-interp *acpi_pm

You can change the timesource at runtime by doing something like:

echo "tsc" > /sys/devices/system/timesource/timesource0/timesource

The "*" denotes the current timesource, so you'll see it move the next
time you cat the timesource sysfs file.

Could you see if the slowness you're feeling is correlated to the
acpi_pm timesource? It is quite a bit slower to access then the TSC, but
I'd be surprised if you can actually feel the difference.

This is on an x86-64 system, correct?

thanks
-john