[Speed] performance: remove "pure python" pickle benchmarks?

[Nick Coghlan]

On 4 April 2017 at 21:43, Victor Stinner <victor.stinner at gmail.com> wrote:
> 2017-04-04 12:06 GMT+02:00 Serhiy Storchaka <storchaka at gmail.com>:
>> I consider it as a benchmark of Python interpreter itself.
>
> Don't we have enough benchmarks to test the Python interpreter?
>
> I would prefer to have more realistic use cases than "reimplement
> pickle in pure Python".
>
> "unpickle_pure_python" name can be misleading as well to users
> exploring speed.python.org data, no?

The split benchmark likely made more sense in Python 2, when "import
pickle" gave you the pure Python version by default, and you had to do
"import cPickle as pickle" to get the accelerated version - you'd get
very different performance characteristics based on which import the
application used.

It makes significantly less sense now that Python 3 always using the
accelerated version by default and only falls back to pure Python if
the accelerator module is missing for some reason. If anything, the
appropriate cross-version comparison would be between the pure Python
version in 2.7, and the accelerated version in 3.x, since that
reflects the performance change you get when you do "import pickle".

However, that argument only applies to whether or not to include it in
the default benchmark set used to compare the overall performance
across versions and implementations - it's still valid as a
microbenchmark looking for major regressions in the speed of the pure
Python fallback.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia