Re: scheduler latency

[Davide Libenzi <davidel@xmailserver.org>]

On Thu, 29 Apr 2004, Nick Piggin wrote:

> I've done some scheduler latency tests and come up with some
> pretty plots, so I thought I'd post them. It is nicksched vs
> mainline.
> 
> Note: this is not realtime scheduling latency, but latency as
> measured by my random program. It also does not indicate
> interactivity, because the latencies measured were all under
> 15ms which is probably below perception. Even if not, it
> doesn't measure latency as you might see it.
> 
> Finally, some of the tests involved me moving the mouse around,
> so factor in by subliminal (or not) bias toward my scheduler.
> 
> http://www.kerneltrap.org/~npiggin/schedlat3/index.html

Nick, when I did the SOFTRR hack, I also measured sched latencies using 
another measurement/load apps:

http://www.xmailserver.org/linux-patches/softrr.html

At the bottom you can find the measurement app (note: x86 only since it 
uses "rdtsc") and stressful (latency-wise) loads.



- Davide