kern/85820: 1.5 times slower performance with SCHED_ULE than SCHED_4BSD

[Mark Linimon]

On Mon, Oct 09, 2006 at 10:28:51PM +0200, O. Hartmann wrote:
> I never realized, that SCHED_ULE has been discarded from being the
> default scheduler in FreeBSD 6.X, as I can remember, SCHED_ULE has been
> promoted to be the default scheduler due to its improvements to SMP.

Yes, it was, but as time went on, more work was being done on the kernel
in performance improvements in areas other than the scheduler.  Whether
or not these affected ULE's performance is not clear to me.  However, this
is a good example of the type of thing that you have to follow discussions
on the -current mailing list to keep up with.

> Well, I may be wrong, but it would be much more convenient having those
> important informations being released more public

There hasn't been any effort to keep this information confidential.  It's
just that individuals' efforts have been going on in areas other than ULE,
and it is possible that ULE just hasn't kept up with those changes.

These things aren't as cut-and-dried as you seem to think that they are.

mcl