Re: [sched, patch] better wake-balancing, #2

From: Con Kolivas
Date: Sat Jul 30 2005 - 23:36:49 EST

On Sun, 31 Jul 2005 09:26, Chuck Ebbert wrote:
> On Fri, 29 Jul 2005 at 17:02:07 +0200, Ingo Molnar wrote:
> > do wakeup-balancing only if the wakeup-CPU is idle.
> >
> > this prevents excessive wakeup-balancing while the system is highly
> > loaded, but helps spread out the workload on partly idle systems.
> I tested this with Volanomark on dual-processor PII Xeon -- the
> results were very bad:
> Before: 5863 messages per second

> After: 5569 messages per second

Can you check schedstats or otherwise to find if volanomark uses
sched_yield() ? When last this benchmark came up, it appeared that no jvm
used futexes and left locking to yielding. We really should find out if that
is the case before trying to optimise for this benchmark.


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