Messages in this thread | | | Subject | Re: [PATCH v8 0/9] rwsem performance optimizations | From | Tim Chen <> | Date | Wed, 16 Oct 2013 14:55:30 -0700 |
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> > It would be _really_ nice to stick this into tools/perf/bench/ as: > > perf bench mem pagefaults > > or so, with a number of parallelism and workload patterns. See > tools/perf/bench/numa.c for a couple of workload generators - although > those are not page fault intense. > > So that future generations can run all these tests too and such. > > > I compare the throughput where I have the complete rwsem patchset > > against vanilla and the case where I take out the optimistic spin patch. > > I have increased the run time by 10x from my pervious experiments and do > > 10 runs for each case. The standard deviation is ~1.5% so any changes > > under 1.5% is statistically significant. > > > > % change in throughput vs the vanilla kernel. > > Threads all No-optspin > > 1 +0.4% -0.1% > > 2 +2.0% +0.2% > > 3 +1.1% +1.5% > > 4 -0.5% -1.4% > > 5 -0.1% -0.1% > > 10 +2.2% -1.2% > > 20 +237.3% -2.3% > > 40 +548.1% +0.3% > > The tail is impressive. The early parts are important as well, but it's > really hard to tell the significance of the early portion without having > an sttdev column. > > ( "perf stat --repeat N" will give you sttdev output, in handy percentage > form. )
Quick naive question as I haven't hacked perf bench before. Now perf stat gives the statistics of the performance counter or events. How do I get it to compute the stats of the throughput reported by perf bench?
Something like
perf stat -r 10 -- perf bench mm memset --iterations 10
doesn't quite give what I need.
Pointers appreciated.
Tim
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