Re: [REPORT] cfs-v4 vs sd-0.44

Ingo Molnar
2007-04-21T15:46:57Z

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

> I promised to perform some tests on your code. I'm short in time right
> now, but I observed behaviours that should be commented on.

thanks for the feedback!

> 3) CFS-v4
>
> Feels even better, mouse movements are very smooth even under high
> load. I noticed that X gets reniced to -19 with this scheduler. I've
> not looked at the code yet but this looked suspicious to me. I've
> reniced it to 0 and it did not change any behaviour. Still very
> good. The 64 ocbench share equal CPU time and show exact same
> progress after 2000 iterations. The CPU load is more smoothly spread
> according to vmstat, and there's no idle (see below). BUT I now
> think it was wrong to let new processes start with no timeslice at
> all, because it can take tens of seconds to start a new process when
> only 64 ocbench are there. [...]

ok, i'll modify that portion and add back the 50%/50% parent/child CPU
time sharing approach again. (which CFS had in -v1) That should not
change the rest of your test and should improve the task startup
characteristics.

Ingo