Re: [PATCH] More time clean up stuff.

From: george anzinger (
Date: Tue Jun 10 2003 - 10:40:24 EST

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.
> ---
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George Anzinger
Preemption patch:

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