cpu scaling questions

Dave Jones davej at redhat.com
Mon Oct 2 16:01:15 UTC 2006


On Mon, Oct 02, 2006 at 09:45:27AM -0400, Thomas J. Baker wrote:
 > 
 > I've got two questions related to cpu scaling. On my laptop I've got a
 > Core 2 Duo. Can the two cores scale frequencies independently?

No. Think about it. You have a single package, with a single power source.

 > Most of
 > the time that doesn't seem like the case but every once in a while, my
 > cpufreq applets show different speeds. I'm assuming that there is just a
 > bit of slop involved and the two cores are always the same speed.

It's a bug, but it should be cosmetic only. It's on the TODO, but
there are a number of other issues in this code that need tackling
first before it gets clean enough to fix this properly.
FC6-update/FC7 stuff.

 > On my desktop, I've got Xeon CPUs that support limited scaling; they run
 > at either 2.8 or 3.4GHz. On FC5, they used to scale on demand but under
 > FC6 they don't and the cpufreq applet has a manual setting for 2.8 or
 > 3.4 with an automatic setting that is greyed out.

Which cpufreq driver were they using ?
File a kernel bug, and attach dmesg.

	Dave
 




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