On Wed, Feb 28, 2007 at 02:32:43AM -0800, Bizhan Gholikhamseh (bgholikh) wrote: > I have a simple program utilizing "sleep()" api to sleep 3 msec > periodically. > I measured the time difference before calling the api and after it > returns back. > The same application behaves differently running on Linux 2.4 and 2.6 > In Linux 2.6.11, it takes about 3 msec, and running on Linux 2.4.20 it > takes about 10 msec. Your 2.6 kernel probably runs with HZ=1000. 2.4 kernels run with HZ=100, so the minimum sleep time is actually 1/HZ = 10 msec. Note that with any userland sleep function, the wanted sleep time is a minimum and not a guarantee that you will be woken up right after the wanted sleep time. Erik -- They're all fools. Don't worry. Darwin may be slow, but he'll eventually get them. -- Matthew Lammers in alt.sysadmin.recovery
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