HEADS UP: ULE is the default scheduler now
Marc G. Fournier
scrappy at hub.org
Sun Jan 25 16:16:57 PST 2004
Jeff, were you able to clear up the use of ULE on a single CPU machine
with SMP enabled?
On Sat, 24 Jan 2004, Jeff Roberson wrote:
> On Sat, 24 Jan 2004, Jeff Roberson wrote:
> > ULE has entered into its probationary period as the default scheduler.
> > This is intended to give it wider exposure to work out the last few kinks.
> > If all goes well it will remain the default through the rest of the 5.x
> > series. If you aren't running it now, please switch over.
> > I have been out of town or very busy over the last few months. I should
> > be more available to address things as they come up now. If anyone is
> > aware of any current issues, please contact me with any details you may
> > have.
> I was asked to follow up with a summary of why you might want to use ULE.
> For the average user, interactivity is reported to be better in many
> cases. This means less skipping, jerking, etc. in interactive
> applications while the machine is very busy. This will not prevent
> problems due to overload disk subsystems, but it does help with overloaded
> On SMP machines ULE has per cpu run queues which allow for CPU
> affinity, CPU binding, advanced HyperThreading support, as well as
> providing a framework for more optimizations in the future. This means
> that as our kernel is locked better the scheduler will be able to make
> more efficient use of the available parallel resources.
> ULE has been stable for some time. The only problems that are likely to
> remain are corner cases where interactivity is not as good or where
> performance is not as good as with the old scheduler.
> > Thanks,
> > Jeff
> freebsd-current at freebsd.org mailing list
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Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org Yahoo!: yscrappy ICQ: 7615664
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