lkml.org 
[lkml]   [2013]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v8 0/9] rwsem performance optimizations
From
Date

>
> 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



\
 
 \ /
  Last update: 2013-10-17 00:21    [W:0.135 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site