Messages in this thread | | | Subject | Re: [PATCH -v8][RFC] mutex: implement adaptive spinning | From | Peter Zijlstra <> | Date | Mon, 12 Jan 2009 18:16:21 +0100 |
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On Mon, 2009-01-12 at 08:20 -0800, Linus Torvalds wrote: > > On Mon, 12 Jan 2009, Linus Torvalds wrote: > > > > You made it back into the locked version. > > Btw, even if you probably had some reason for this, one thing to note is > that I think Chris' performance testing showed that the version using a > lock was inferior to his local btrfs hack, while the unlocked version > actually beat his hack. > > Maybe I misunderstood his numbers, though. But if I followed that sub-part > of the test right, it really means that the locked version is pointless - > it will never be able to replace peoples local hacks for this same thing, > because it just doesn't give the performance people are looking for. > > Since the whole (and _only_) point of this thing is to perform well, > that's a big deal.
Like said in reply to Chris' email, I just wanted to see if fairness was worth the effort, because the pure unlocked spin showed significant unfairness (and I know some people really care about some level of fairness).
Initial testing with the simple test-mutex thing didn't show too bad numbers.
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