Re: [sched] 143e1e28cb4: +17.9% aim7.jobs-per-min, -9.7% hackbench.throughput

[Fengguang Wu]

On Mon, Aug 11, 2014 at 03:33:52PM +0200, Peter Zijlstra wrote:
> On Sun, Aug 10, 2014 at 06:54:13PM +0800, Fengguang Wu wrote:
> > This view may be easier to read, by grouping the metrics by test case.
> > 
> > test case: brickland1/aim7/6000-page_test
> 
> OK, I have a similar system to the brickland thing (slightly different
> configuration, but should be close enough).
> 
> Now; do you have a description of each test-case someplace?

You can find our aim7 test script here:

        git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests
        cd lkp-tests
        vi tests/aim7

More test scripts are available there:

        vi tests/hackbench
        vi tests/netperf
        ...

> In particular, it might be good to have a small annotation to show
> which direction is better.

The directions are listed in these files as positive/negative numbers:

        vi metric/index-*

For examples:

% head -3 metric/index-*
==> metric/index-latency.yaml <==
dbench.max_latency: -0.1
fileio.request_latency_95%_ms: -0.2
oltp.request_latency_95%_ms: -0.2

==> metric/index-perf.yaml <==
aim7.jobs-per-min: 1
dbench.throughput-MB/sec: 1
ebizzy.throughput: 1

==> metric/index-power.yaml <==
turbostat.Pkg_W: -1
turbostat.RAM_W: -1
turbostat.%c0: -0.1

==> metric/index-size.yaml <==
kernel-size.text: -1
kernel-size.data: -1
kernel-size.bss: -1

They are not the comprehensive list, but reasonably complete to list
the most important ones.

> >     128529 Â 1%     +17.9%     151594 Â 0%  TOTAL aim7.jobs-per-min
> 
> jobs per minute, + is better, so no worries there.
> 
> >     582269 Â14%     -55.6%     258617 Â16%  TOTAL softirqs.SCHED
> >     993654 Â 2%     -19.9%     795962 Â 3%  TOTAL softirqs.RCU
> >   15865125 Â 1%     -15.0%   13485882 Â 1%  TOTAL softirqs.TIMER
> 
> >   59366697 Â 3%     -46.1%   32017187 Â 7%  TOTAL cpuidle.C1-IVT.time
> >      54543 Â11%     -37.2%      34252 Â16%  TOTAL cpuidle.C1-IVT.usage
> >      19542 Â 9%     -38.3%      12057 Â 4%  TOTAL cpuidle.C1E-IVT.usage
> >   49527464 Â 6%     -32.4%   33488833 Â 4%  TOTAL cpuidle.C1E-IVT.time
> >      76064 Â 3%     -32.2%      51572 Â 6%  TOTAL cpuidle.C6-IVT.usage
> 
> Less idle time; might be good, if the work is cpubound, might be bad if
> not; hard to say.
> 
> >       2.82 Â 3%     +21.9%       3.43 Â 4%  TOTAL turbostat.%pc2
> >       4.40 Â 2%     +22.0%       5.37 Â 4%  TOTAL turbostat.%c6
> >      15.75 Â 1%      -3.4%      15.21 Â 0%  TOTAL turbostat.RAM_W
> 
> >    3150464 Â 2%     -24.2%    2387551 Â 3%  TOTAL time.voluntary_context_switches
> 
> Typically less ctxsw is better..
> 
> >        281 Â 1%     -15.1%        238 Â 0%  TOTAL time.elapsed_time
> >      29294 Â 1%     -14.3%      25093 Â 0%  TOTAL time.system_time
> 
> Less time spend (on presumably the same work) is better
> 
> >    4529818 Â 1%      -8.8%    4129398 Â 1%  TOTAL time.involuntary_context_switches
> 
> Less preemptions, also generally better
> 
> >      10655 Â 0%      +1.4%      10802 Â 0%  TOTAL time.percent_of_cpu_this_job_got
> 
> Seem an improvement; not sure.
> 
> Many more stats.. but from the above it looks like its an overall 'win';
> or am I reading the thing wrong?

I'd agree with your interpretations, too.

In case you want to make sure the exact meaning of the above values:
they are generated by scripts in stats/* and stats/hackbench would be
a good example to read.

Thanks,
Fengguang
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