Some tips for benchmarking

[George Rimar via llvm-commits]

>After much pain I decided that instead of just running tests many
>times I should put some effort in figuring out why perf numbers were
>so hard to reproduce on my machine.
>
>I was already disabling address space randomization and setting the
>scaling_governor to performance. Other things I found
>
>* Use https://github.com/lpechacek/cpuset to reserve a cpu for just
>the program you are benchmarking.
>* Disable the SMP pair (echo 0 > /sys/devices/system/cpu/cpuX/online)
>of the cpu you will use for the benchmark.
>* disable turbo mode (echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo).
>
>The results are pretty awesome:
>
>3.012355647 seconds time elapsed         ( +-  0.01% )
>
>:-)

That might be helpful, thanks for sharing !

Cheers,
Rafael