Re: I like SCHED_4BSD

> 
> 
> On Thu, 11 Mar 2004, Ian FREISLICH wrote:
> 
> > > > o Better interactivity -- No mouse jerkiness, no sluggish screen update
s =
> > > when
> > > >   switching between virtual desktops, etc.
> > > >=20
> > > > o Better scheduling!  I'm serious here.  Watching top under SCHED_ULE, 
I'm
> > > >   seeing 10, 15, 20 seconds go by where ALL processes are sleeping.=20
> > > >   Processes seem to be spending inordinate amounts of time in the "kser
el"
> > > >   state.  This, of course, doesn't happen with SCHED_4BSD.
> > > 
> > > That this observation may well be bogus, because you're trying to
> > > measure the scheduler using a tool that is itself run by the
> > > scheduler, so the process stats you see may not be representative of
> > > what is really happening on your system.
> > 
> > That point is taken, however, on my old SMP box _ULE adds an extra
> > ~5000 seconds of wall clock time to a 'make buildworld -j8' compared
> > to _BSD 'make world -j8'.
> > 
> > I did some tests about 3 weeks ago using bind-dlz and postgresql-7.4.1
> > on this same machine trying libc_r and libkse using both schedulers.
> > ULE results with either thread library were dismal ~.33 that of
> > BSD: ULE gave about 17 authoritive lookups a second with BSD giving
> > about 50.  The KSE library only dropped the rate by about 2 lookups
> > per second on both schedulers which is essentially noise, but I had
> > expected an improvement.
> 
> Re: KSE....
> We have not yet begun to fight^H^H^H^H^Hoptimise
> see what happens if you disable the halt on idle 
> sysctl machdep.cpu_idle_hlt=0
> The machine will get hotter but it may affect the outcome..
> Just curious.

Do you think that this may also affect ULE?  BTW, the CPUs are
already hot because they're continuously running the dnetc client.

Ian

--
Ian Freislich