Re: [PATCH 0/4] per anon_vma lock and turn anon_vma rwsem lock to rwlock_t

Davidlohr Bueso
2013-11-02T03:15:19Z

On Fri, 2013-11-01 at 18:16 +0800, Yuanhan Liu wrote:
> On Fri, Nov 01, 2013 at 09:21:46AM +0100, Ingo Molnar wrote:
> >
> > * Yuanhan Liu <yuanhan.liu@linux.intel.com> wrote:
> >
> > > > Btw., another _really_ interesting comparison would be against
> > > > the latest rwsem patches. Mind doing such a comparison?
> > >
> > > Sure. Where can I get it? Are they on some git tree?
> >
> > I've Cc:-ed Tim Chen who might be able to point you to the latest
> > version.
> >
> > The last on-lkml submission was in this thread:
> >
> > Subject: [PATCH v8 0/9] rwsem performance optimizations
> >
>
> Thanks.
>
> I queued bunchs of tests about one hour ago, and already got some
> results(If necessary, I can add more data tomorrow when those tests are
> finished):

What kind of system are you using to run these workloads on?

>
>
> v3.12-rc7 fe001e3de090e179f95d
> ------------------------ ------------------------
> -9.3% brickland1/micro/aim7/shared
> +4.3% lkp-ib03/micro/aim7/fork_test
> +2.2% lkp-ib03/micro/aim7/shared
> -2.6% TOTAL aim7.2000.jobs-per-min
>

Sorry if I'm missing something, but could you elaborate more on what
these percentages represent? Are they anon vma rwsem + optimistic
spinning patches vs anon vma rwlock?

Also, I see your running aim7, you might be interested in some of the
results I found when trying out Ingo's rwlock conversion patch on a
largish 80 core system: https://lkml.org/lkml/2013/9/29/280

Thanks,
Davidlohr