Re: [CFT][RFC] HT scheduler

[Rusty Russell]

In message <3FD8317B.4060207@xxxxxxxxxxxxxxx> 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.
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