Messages in this thread | | | Date | Mon, 11 Aug 2008 21:33:17 +0200 | From | Dominik Brodowski <> | Subject | Re: cpufreq doesn't seem to work in Intel Q9300 |
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Hi,
On Mon, Aug 11, 2008 at 07:11:28AM -0700, Arjan van de Ven wrote: > 1) when the cpu is idle (as in "idle loop C states/hlt"; p4_clockmod > doesn't mean anything.. the clock is stopped not just skipped. > 2) when the cpu is executing code (eg non-idle), it takes more power > for a unit of time than it takes when it's idle
This statement might be true, but might also be wrong: a) on systems where only C1 is exported, p4-clockmod most often equals the state the CPU is in when in C1[*], so we're in a win-win, or lose-lose situation. b) IIRC 50% throttling is not "execute-one-statement skip-one-statement execute-one-statement, etc." but instead work for N us, skip for N us, work for N us, etc. Therefore, the situation is a bit more compilcated.
Still, I agree that p4-clockmod is useful mostly in corner cases (and for developing the cpufreq infrastructure in the first case, but that's another story)
[*] or C2 even?
Best, Dominik
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