From: Valdis.Kletnieks@vt.edu
To: pradeep hettiarachchi <pradeepmh@wayne.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Frequency Scaling on Intel Core 2 Duo Processors
Date: Tue, 27 Oct 2009 07:31:08 -0400 [thread overview]
Message-ID: <43501.1256643068@turing-police.cc.vt.edu> (raw)
In-Reply-To: Your message of "Mon, 26 Oct 2009 11:06:23 EDT." <8fe204b0910260806l10896f9foc0568dd0b8f4b6ca@mail.gmail.com>
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On Mon, 26 Oct 2009 11:06:23 EDT, pradeep hettiarachchi said:
> Hi,
>
> I am working on a research in real-time systems. If I want to change
> the frequency of the system as rapidly as possible, what is the best
> method ? At the moment I write MSR_IA32_PERF_CTL, MSR directly with
> the pre-found(calculated, encoded) values** for different frequencies.
> I found the entire transition (latency) takes multiple milliseconds to
> complete; however, I want some faster method to change the CPU
> frequency.
You're going to have a hard time making it switch any faster than the value
listed in /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency
though I admit I'm not awake enough yet to be sure what the units of that file
are...
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prev parent reply other threads:[~2009-10-27 11:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-26 15:06 pradeep hettiarachchi
2009-10-27 11:31 ` Valdis.Kletnieks [this message]
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