Messages in this thread | | | Date | Tue, 10 Jun 2003 08:40:24 -0700 | From | george anzinger <> | Subject | Re: [PATCH] More time clean up stuff. |
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Riley Williams wrote: > Hi George. > > I'm ignoring the rest of this - it makes sense to me, but I'm > no expert in it. However, your last point is one I can comment > about as I've dealt with it professionally many times. > > > clock_nanosleep is changed to round up to the next jiffie to > > cover starting between jiffies. > > Isn't this a case of replacing one error with another, where > one of the two errors is unavoidable? > > 1. In the old case, the sleep will on average be half a jiffie > LESS than the requested period. > > 2. In the new case, the sleep will on average be half a jiffie > MORE than the requested period. > > One or the other is unavoidable if a jiffie is the basic unit > of time resolution of the system. However, the error is totally > meaningless if we are asking to sleep for more than 15 jiffies.
I had a hard time justifiying this also. I would really like to have better resolution. As to which choice to make, the standard is VERY clear here: No timer or sleep shall complete BEFORE its time. > > Best wishes from Riley. > --- > * Nothing as pretty as a smile, nothing as ugly as a frown. > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.488 / Virus Database: 287 - Release Date: 5-Jun-2003 > >
-- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml
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