lkml.org 
[lkml]   [2003]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] More time clean up stuff.
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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:36    [W:0.041 / U:3.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site