Re: [PATCH 0/3 v2] mutex: Improve mutex performance by doing lessatomic-ops & better spinning

[Ingo Molnar]

* Waiman Long <Waiman.Long@xxxxxx> wrote:

> [...]
> 
> Patches 2 improves the mutex spinning process by reducing contention among the 
> spinners when competing for the mutex. This is done by using a MCS lock to put 
> the spinners in a queue so that only the first spinner will try to acquire the 
> mutex when it is available. This patch showed significant performance 
> improvement of +30% on the AIM7 fserver and new_fserver workload.

Ok, that's really nice - and this approach has no arbitrary limits/tunings in it.

Do you have a performance comparison to your first series (patches 1+2+3 IIRC) - 
how does this new series with MCS locking compare to the best previous result from 
that old series? Do we now achieve that level of performance?

Thanks,

	Ingo
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