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Re: [RFC] Lock elision "test suite", first draft


On Wed, Aug 07, 2013 at 02:20:10PM +0200, OndÅej BÃlka wrote:
> On Wed, Aug 07, 2013 at 02:07:23PM +0200, Dominik Vogt wrote:
> > Test results on z/Architecture (zEC12)
> > --------------------------------------
> > 
> > Test Setup:
> > 
> >   An lpar with eight CPUs on a ZEC12.  8 GiB RAM.
> > 
> > Test execution:
> > 
> >   Each test case was run ten times in a loop using an unpatched
> >   glibc-2.15 (Ubuntu standard) ("old glibc"), a new glibc-2.18
> >   with elision disabled ("elision n/a"), and a new glibc-2.18
> >   with elision enabled ("elision on").
> snip
> > ./ets-t3
> > =========
> > 
> > old glibc:
> > ----------
> > pct_best  : 100.00...%
> > pct_mindev: 4.57...%
> > pct_maxdev: 5.43...%
> > pct_stddev: 3.61...%
> > 
> > elision n/a:
> > ------------
> > pct_best  : 96.79...%
> > pct_mindev: 9.82...%
> > pct_maxdev: 9.42...%
> > pct_stddev: 5.71...%
> > 
> > elision on:
> > -----------
> > pct_best 593.48...%
> > pct_mindev: 5.73...%
> > pct_maxdev: 4.09...%
> > pct_stddev: 3.43...%
> > 
> Do you know why elision is 6 times slower on this test?

The throughput is six times of the throughput without elision.
The percentages of pct_best are relative performance compared with
glibc-2.15.

Vice versa, an explanation is needed for the performance of the
tests 1, 2, 4 and 5.  I'm working on that and will post individual
analyses of the tests soon.

Ciao

Dominik ^_^  ^_^

-- 

Dominik Vogt
IBM Germany


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