Re: sched regression introduced by NO_NEW_FAIR_SLEEPERS

[drago01]

On Sun, Sep 27, 2009 at 9:47 PM, drago01 <drago01@xxxxxxxxx> wrote:
> Hi,
>
> Chuck has backported some scheduler patches from 2.6.32 to the fedora kernel.
>
> I did the following test to test the new scheduler (cpu is a core i7
> 920 4 cores + HT).
>
> run 8 "md5sum /dev/urandom" task and try to use the desktop (compiz).
>
> The result was that moving windows or rotating the cube is very slow.
> (same happens with pure metacity but is is worse in compiz).
>
> Mounting debugfs and doing "echo NEW_FAIR_SLEEPERS > sched_features"
> results into a useable desktop while the 8 md5sum tasks are running
> (ie. the system behaves as if they where not running at all from an
> interactivity pov).
>
>
> P.S: please CC me when replying.
>

With "NEW_FAIR_SLEEPERS" I can even run 100(!)  "md5sum" task without
any effect on interactivity. (still have not found a number of tasks
needed to make the system unresponsive as with 8 with
"NO_NEW_FAIR_SLEEPERS".
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/