Re: [patch] CFS scheduler, -v19

Mike Galbraith
2007-07-15T05:25:49Z

On Sat, 2007-07-14 at 13:19 -0400, Ed Tomlinson wrote:
> Hi,

Hi Ed,

> I run a java application at nice 15. Its been a background application here for as long
> as SD and CFS have been around. If I have a compile running at nice 0, with v19 java
> gets so little cpu that the the wrapper that runs to monitor it is timing out waiting for
> it to start. This is new in v19 - something in v19 is not meshing well with my mix
> of applications...
>
> Kernel is gentoo 2.6.22-r1 + cfs v19
>
> How can I help to debug this?

I hear Ingo is off having a genuine long weekend, but in the meantime,
you could try echo 30 > /proc/sys/kernel/sched_features to eliminate the
sleeper fairness changes in v19, since that was the biggest change.

Sending a few seconds of logged /proc/sched_debug will also help get a
picture of what's happening, and lovely would be a method to reproduce
the problem locally.

-Mike