Re: [CFT][RFC] HT scheduler

Rusty Russell
2003-12-12T01:09:24Z

In message <3FD8317B.4060207@cyberone.com.au> you write:
>
>
> Nick Piggin wrote:
>
> >
> > Don't ask me why it runs out of steam at 150 rooms. hackbench does
> > something similar. I think it might be due to some resource running
> > short, or a scalability problem somewhere else.
>
>
> OK, it is spinning on .text.lock.futex. The following results are
> top 10 profiles from a 120 rooms run and a 150 rooms run. The 150
> room run managed only 24.8% the throughput of the 120 room run.
>
> Might this be a JVM problem?

Not if hackbench is showing it.

> I'm using Sun Java HotSpot(TM) Server VM (build 1.4.2_01-b06, mixed mode)
>
> ROOMS 120 150
> PROFILES
> total 100.0% 100.0%
> default_idle 81.0% 66.8%
> .text.lock.rwsem 4.6% 1.3%
> schedule 1.9% 1.4%
> .text.lock.futex 1.5% 19.1%

Increase FUTEX_HASHBITS?

Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.