Re: [PATCH v2 2/4] sched:Consider imbalance_pct when comparing loads in numa_has_capacity

From: Ingo Molnar
Date: Tue Jun 23 2015 - 10:37:11 EST



* Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> wrote:

> * Ingo Molnar <mingo@xxxxxxxxxx> [2015-06-23 10:10:39]:
> > > Please let me know if there are any better ways to observe the
> > > spread. [...]
> >
> > There are. I see you are using prehistoric tooling, but see the various NUMA
> > convergence latency measurement utilities in 'perf bench numa':
> >
> > vega:~> cat numa01-THREAD_ALLOC
> >
> > perf bench numa mem --no-data_rand_walk -p 2 -t 16 -G 0 -P 0 -T 192 -l 1000 -zZ0c $@
> >
> > You can generate very flexible setups of NUMA access patterns, and measure their
> > behavior accurately.
> >
> > It's all so much more capable and more flexible than autonumabench ...
>
> Okay, thanks for the hint, I will try this out in future.
>
> >
> > Also, when you are trying to report numbers for multiple runs, please use
> > something like:
> >
> > perf stat --null --repeat 3 ...
> >
> > This will run the workload 3 times (doing only time measurement) and report the
> > stddev in a human readable form.
> >
>
> Thanks again for this hint. Wouldnt system time/ user time also matter?

Yeah, would be nice to add stime/utime output to 'perf stat', so that it's an easy
replacement for /usr/bin/time.

I've Cc:-ed perf folks who might be able to help out.

Thanks,

Ingo
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