On Mon, 12 Feb 2007 16:44:22 +1100 "Con Kolivas" <[email protected]> wrote: > > 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. That is not true on all architecures, some do more accurate accounting by recording the times at user/kernel/interrupt transitions ... -- Cheers, Stephen Rothwell [email protected] http://www.canb.auug.org.au/~sfr/
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