Messages in this thread | | | Subject | Re: [PATCH -v8][RFC] mutex: implement adaptive spinning | From | Peter Zijlstra <> | Date | Mon, 12 Jan 2009 17:50:15 +0100 |
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On Mon, 2009-01-12 at 11:45 -0500, Chris Mason wrote: > 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. > > > > The spinning hack was faster than everything before v7 (we'll call it > the Linus-fix), and the v7 code was much faster than my spin. > > This is somewhere in between, with slightly better fairness than v7. > > spin v7 v8 > dbench 50 580MB/s 789MB/s 421MB/s > file creates 152 file/s 162 file/s 195 file/s > file stat 3.8s total 2.3s total 5.3s total > > (the file stat run is total run time, so lower is better. The other > numbers are files or MB per second, so higher is better) > > For the file create run, v8 had much lower system time than v7, > averaging 1s of sys time per proc instead of 1.6s.
Right, how about the spread in completion time, because that is the only reason I tried this fairness stuff, because you reported massive differences there.
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