ULE nice behavior fixed.

[Jeff Roberson]

On Thu, 3 Apr 2003, Bruce Evans wrote:

> On Wed, 2 Apr 2003, Jeff Roberson wrote:
>
> > On Wed, 2 Apr 2003, Bruce Evans wrote:
> > > ...  The scaling of niceness was re-broken in -current about 3
> > > years ago to "fix" the priority inversion problems.  This is with
> > > SCHED_4BSD.  SCHED_ULE has larger problems.
> >
> > Do you know of any problem other than idlepri breakage?  I just fixed
> > that.  I'm about to get on a plane so I don't have time to benchmark it.
> > If you have a chance I'd love to see how the most recent fixes effect your
> > buildworld time.
>
> Nothing very important.  Many scheduler-related fields shown by ps are
> now useless since they only have a dummy entry in them.  IIRC, one is
> worse than useless since the dummy entry doesn't fit in the field width.
>

Ah, right, you're talking about the weighted cpu?  Some of these corners
need to be cleaned up.  I wanted to get other behavior cleaned up first.

What is your impression of ULE?  What do you think would be required for
it to become the default scheduler?  I mean, other than lots of
time and benchmarking to prove it.

I need to work on the cpu rebalancing code a bit more.  I also want to do
a fuzzy rescheduling mode that will notice how many interactive threads
there are and mi_switch less agressively if there are none.  My
measurements show that this could have a huge perf impact on some
workloads.

Cheers,
Jeff