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

From: Srikar Dronamraju
Date: Tue Jun 23 2015 - 09:02:52 EST

* 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?
I guess once Mel did point out that it was important to make sure that
system time and user time dont increase when elapsed time decreases. But
I cant find the email though.

Thanks and Regards
Srikar Dronamraju

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