Messages in this thread | | | Date | Wed, 14 Jan 2009 12:21:58 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH -v9][RFC] mutex: implement adaptive spinning |
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* Chris Mason <chris.mason@oracle.com> wrote:
> v10 is better that not spinning, but its in the 5-10% range. So, I've > been trying to find ways to close the gap, just to understand exactly > where it is different. > > If I take out: > /* > * If there are pending waiters, join them. > */ > if (!list_empty(&lock->wait_list)) > break; > > > v10 pops dbench 50 up to 1800MB/s. The other tests soundly beat my > spinning and aren't less fair. But clearly this isn't a good solution.
i think since we already decided that it's ok to be somewhat unfair (_all_ batching constructs introduce unfairness, so the question is never 'should we?' but 'by how much?'), we should just take this out and enjoy the speed ...
Ingo
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