ULE vs. 4BSD in RELENG_7

Manjunath R Gowda mgowda82 at gmail.com
Wed Oct 24 10:12:23 PDT 2007

On 10/24/07, Josh Carroll <josh.carroll at gmail.com> wrote:
> > Yes, that's the proper default. You could try setting steal_thresh to 1.
> I
> > noticed a problem with building ports on an 8 core Xeon system while 8
> > distributed.net crunchers were running. The port build would proceed
> > incredibly slowly, steal_thresh=1 helped a little bit. It might not make
> up
> > the 5% gap you're seeing though. During early ULE2/3 testing the other
> > variables Jeff recommended trying were sched.pick_pri (which I never saw
> > effect from), sched_tryself and sched.balance. They're all bools IIRC.
> Since
> > this workload is a bit different from any of mine it would be worthwhile
> to
> > try those variables.
> Thanks for the information. Setting sched_tryself to 0 improved things
> slightly. sched.balance didn't seem to help. I'm trying to
> increase/decrease the balance_interval to see if that helps.

It's worth noting that there are kernel threads competing to run as well.
For example ithread and taskqueue threads. How does ULE differentiate and
schedule I/O bound threads?

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