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Re: [PATCH 1/1] benchtest: Run benchmark only once for each input
On Thursday 06 July 2017 02:21 PM, Ashwin Sekhar T K wrote:
> Currently for each input in the input file, the benchtest framework
> runs the microbenchmark in a loop a specific number of times before
> it moves onto the next input. This has the drawback that it might
> eliminate the cache effects and branch effects that we see in real
> world programs.
>
> This patch changes the framework in such a way that the microbenchmark
> is run only once for each input before moving onto the next input.
This is solved with Wilco's workload addition patch. That is, for
workload tests it makes sense to have cache effects in place since the
call sequence kinda resembles a real workload - note that there is still
a non-trivial effect due to other code in the program that cannot be
emulated without actually running the program itself.
These inputs on the other hand simply exercise branches of the program
to measure the variance in performance across branches irrespective of
caching. I'm open to changing the constitution of the inputs to a
different model, but running them exactly once in that sequence does not
really emulate anything.
Siddhesh