Messages in this thread | | | Date | Wed, 28 Jan 2009 15:05:45 -0600 | From | Wes Felter <> | Subject | Re: a question about p4_clockmod module on Xeon quad core processors |
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Xiaoning Ding wrote: > Hi list, > > I have tried the p4-clockmod module in Linux kernel 2.6.29 on Xeon 5355 quad-core CPUs with no luck. It seems current p4-clockmod driver still cannot support Intel Quad core processors, right? > > I know I can also use acpi-cpufreq. It can only scale down the frequence from 2.67GHz to 2GHz. But I need some lower frequencies for some experiments.
Clock modulation is quite simple; in the past I've done it from userspace with /dev/cpu/*/msr or written my own module to do it. I don't know if I've ever tried it on quad-cores, but it worked on dual-core Woodcrest. (Note: I was not trying to save energy.)
Wes Felter - wesley@felter.org
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