Re: [PATCH -v9][RFC] mutex: implement adaptive spinning

Ingo Molnar
2009-01-13T18:12:22Z

* Linus Torvalds <torvalds@linux-foundation.org> wrote:

>
>
> On Tue, 13 Jan 2009, Peter Zijlstra wrote:
> >
> > Ok, tested only 1, but that was the one I remember lockups from -- and
> > that seems to be good with the cmpxchg.
> >
> > Do you fancy me sending v10 or will you make that change locally?
>
> I'd like to get this in, but I'm not going to apply it in any case
> without way more testing.
>
> It missed the merge window, but I'm potentially willing to let it slip
> in - but only if there are a fair number of people willing to do numbers
> and some harsh testing. Preferably people who did see problems earlier,
> ie at a minimum Chris and Ingo under the loads they used before and saw
> issues with.

I am tracking Peter's code in tip/core/locking:

c10b491: mutex: implement adaptive spinning, v8
c356a7c: mutex: implement adaptive spinning, v7
b89e5d8: mutex: implement adaptive spinning, v6
237ac94: mutex: implement adaptive spinning

And v8 is rock solid in all my testing - and i'll give v10 a similar
workout as well.

Would you prefer a single commit or is this kind of delta development
history useful, with all the variants (at least the later, more promising
ones) included?

The commits are in a tight group with no merges inbetween.

Ingo