Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS]

Ingo Molnar
2007-04-21T10:31:42Z

* Willy Tarreau <w@1wt.eu> wrote:

> I hacked it a bit to make it accept two parameters :
> -R <run_time_in_microsecond> : time spent burning CPU cycles at each round
> -S <sleep_time_in_microsecond> : time spent getting a rest
>
> It now advances what it thinks is a second at each iteration, so that
> it makes it easy to compare its progress with other instances (there
> are seconds, minutes and hours, so it's easy to visually count up to
> around 43200).
>
> The modified code is here :
>
> http://linux.1wt.eu/sched/orbitclock-0.2bench.tgz
>
> What is interesting to note is that it's easy to make X work a lot
> (99%) by using 0 as the sleeping time, and it's easy to make the
> process work a lot by using large values for the running time
> associated with very low values (or 0) for the sleep time.
>
> Ah, and it supports -geometry ;-)
>
> It could become a useful scheduler benchmark !

i just tried ocbench-0.3, and it is indeed very nice!

Would it make sense perhaps to (optionally?) also log some sort of
periodic text feedback to stdout, about the quality of scheduling? Maybe
even a 'run this many seconds' option plus a summary text output at the
end (which would output measured runtime, observed longest/smallest
latency and standard deviation of latencies maybe)? That would make it
directly usable both as a 'consistency of X app scheduling' visual test
and as an easily shareable benchmark with an objective numeric result as
well.

Ingo