Re: [PATCH 2/2] mutex: Apply adaptive spinning on mutex_trylock()

From: Ingo Molnar
Date: Fri Mar 25 2011 - 06:32:01 EST



* Tejun Heo <tj@xxxxxxxxxx> wrote:

> Hello,
>
> On Thu, Mar 24, 2011 at 10:41:51AM +0100, Tejun Heo wrote:
> > USER SYSTEM SIRQ CXTSW THROUGHPUT
> > SIMPLE 61107 354977 217 8099529 845.100 MB/sec
> > SPIN 63140 364888 214 6840527 879.077 MB/sec
> >
> > On various runs, the adaptive spinning trylock consistently posts
> > higher throughput. The amount of difference varies but it outperforms
> > consistently.
>
> I've been running more of these tests and am having doubts about the
> consistency. It seems that, even on a fresh filesystem, some random
> initial condition seems to have persistent effect on the whole run.
> I'll run more tests and report back.

Ok, and there's the deadlock issue as well which Steve noticed.

I'll zap the patches from tip:core/urgent and lets do this via tip:core/locking
with a .40 timeframe and plenty of time of testing.

Thanks,

Ingo
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