[PATCH] MAXCPU alterable in kernel config - needs testers

[John-Mark Gurney]

Kip Macy wrote this message on Sun, Oct 08, 2006 at 15:59 -0700:
> >
> > How would you see a sched_lock decomposition (and, if it is possible,
> > how many locks it could be decomposed in?)
> 
> Rather than having a per thread lock, Solaris uses the lock for the
> current container that a thread is associated with (cpu, run queue,

Wouldn't having a single run queue lock still serialize the cpu's when
getting a thread to run?  Don't we really need a per cpu run queue, and
then have a scheduler that puts threads on the cpu's run queues?

we probably should move some of the stats (LA) to pcpu data structure
and desolving sched_lock from thread priority updates...  This would
mean sched_lock would need to be aquired less often, closer to quantum
(which is ~100ms now) instead of each hz...

There is probably work to be done to push the locks down around
thread, proc and kse/ksg...  It looks like a lot of the work done
each HZ could be a lot more local than it currently is...   It's
probably not so much scheduling over head that is killing sun4v but
the stats gathering..

Though I have very little knowlege about how scheduling works, so I
am probably incorrect..

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."