Messages in this thread | | | From | Al Boldi <> | Subject | Re: [patch 1/3] add basic accounting fields to taskstats | Date | Tue, 8 Aug 2006 17:57:58 +0300 |
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Balbir Singh wrote: > Jay Lan wrote: > > I figured this out. The tsk->stime (and utime as well) are > > charged by 1 tick (or cputime) from the timer interrupt handler > > through update_process_times->account_{user,system}_time. > > > > The clock resolution is a tick. Any short process less than > > 1 tick will the counter being 0. It can be from 0 to 0.99999... > > tick. A half tick is the average value. > > But the scheduling happens in the granularity of a tick, so the minimum > each task gets is a tick. > > > I think it makes more sense to assign a half tick than assign > > 1 usec to the stime. What do you think? Certainly the code need > > better explanation. > > Can't we leave these values as zero in case both stime and utime are zero.
FYI, see "Incorrect CPU process accounting using CONFIG_HZ=100" thread.
IMHO, in-lined process accounting is probably critical for successful scheduling.
Thanks!
-- Al
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