Re: 2.6.11 timeval_to_jiffies() wrong for ms resolution timers
From: George Anzinger
Date: Wed May 25 2005 - 12:59:30 EST
Chris Friesen wrote:
George Anzinger wrote:
Bhavesh P. Davda wrote:
setitimer for 20ms was firing at 21ms
If we do NOT account for this PIT issue, the result is a time drift
that is outside of what ntp can handle...
Still, it is non-intuitive that a multi-GHz machine can't wake you up
more accurately than 1ms.
What about telling it to wake up a jiffy earlier, then checking whether
the scheduling lag was enough to cause it to have waited the full
specified time. If not, put it to sleep for another jiffy.
The user is, of course, free to do what ever they would like. For a more
complete solution you might be interested in HRT (High Res Timers). See my
signature below.
--
George Anzinger george@xxxxxxxxxx
High-res-timers: http://sourceforge.net/projects/high-res-timers/
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