Re: Question about cpu time accuracy.

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Scribbling feverishly on May 12, Jennifer Huang managed to emit:
> Hi all,
>
> I have a question about cpu time accuracy.
>
> I am using kernel 2.4.18. But, when I tried "utime"
> and "nanosleep" to get a process suspended, it only
> worked in 10ms granularity, and it's no way to sleep
> for 1 microsecond.

The standard kernel timer has a resolution of 1/HZ, which is 10ms on
an x86. You could try a scheduling policy of SCHED_FIFO or SCHED_RR,
but this only gets you 2ms resolution.

> Anyone can help me out of this?

There are patches available for high resolution timers:

http://sourceforge.net/projects/high-res-timers/
http://www.cs.wisc.edu/paradyn/libhrtime/

Kurt

-- 
Anarchy may not be the best form of government, but it's better than no
government at all.
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