Messages in this thread | | | Date | Mon, 12 Feb 2007 08:54:25 +0300 (MSK) | From | malc <> | Subject | Re: CPU load |
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On Mon, 12 Feb 2007, Con Kolivas wrote:
> On 12/02/07, Vassili Karpov <av1474@comtv.ru> wrote:
[..snip..]
> The kernel looks at what is using cpu _only_ during the timer > interrupt. Which means if your HZ is 1000 it looks at what is running > at precisely the moment those 1000 timer ticks occur. It is > theoretically possible using this measurement system to use >99% cpu > and record 0 usage if you time your cpu usage properly. It gets even > more inaccurate at lower HZ values for the same reason.
Thank you very much. This somewhat contradicts what i saw (and outlined in usnet article), namely the mplayer+/dev/rtc case. Unless ofcourse /dev/rtc interrupt is considered to be the same as the interrupt from PIT (on X86 that is)
P.S. Perhaps it worth documenting this in the documentation? I caused me, and perhaps quite a few other people, a great deal of pain and frustration.
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