SCHED_ULE should not be the default

[Marcus Reid]

On Mon, Dec 12, 2011 at 04:29:14PM -0800, Doug Barton wrote:
> On 12/12/2011 05:47, O. Hartmann wrote:
> > Do we have any proof at hand for such cases where SCHED_ULE performs
> > much better than SCHED_4BSD?
> 
> I complained about poor interactive performance of ULE in a desktop
> environment for years. I had numerous people try to help, including
> Jeff, with various tunables, dtrace'ing, etc. The cause of the problem
> was never found.

The issues that I've seen with ULE on the desktop seem to be caused by X
taking up a steady amount of CPU, and being demoted from being an
"interactive" process.  X then becomes the bottleneck for other
processes that would otherwise be "interactive".  Try 'renice -20
<pid_of_X>' and see if that makes your problems go away.

Marcus