Re: [PATCH] MAXCPU alterable in kernel config - needs testers

On Mon, 9 Oct 2006, David Xu wrote:

> On Monday 09 October 2006 09:18, Kip Macy wrote:
> > > 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?
> >
> > Balancing run queues has overhead as well. From what I've seen having
> > threads bouncing back and forth between the sleep queue and the run
> > queue because sleep / wakeup is overused (see lockmgr) is a bigger deal
> > right now. Moving to multiple run queues is inappropriate at this time.
> >
> >
> > 					-Kip
>
> If single sched_lock is not removed, it even is not worthy of trying mutliple
> run queues, since any time you spent under sched_lock will be scaled to
> N times, where N is the number of CPU, in worst case. This makes load-balance
> a bit useless.

This is without sched_lock.


			-Kip