[Python-Dev] 2.7 is here until 2020, please don't call it a waste.

[Armin Rigo]

Hi Larry,

On 31 May 2015 at 01:20, Larry Hastings <larry at hastings.org> wrote:
> p.s. Supporting this patch also helps cut into PyPy's reported performance
> lead--that is, if they ever upgrade speed.pypy.org from comparing against
> Python *2.7.2*.

Right, we should do this upgrade when 2.7.11 is out.

There is some irony in your comment which seems to imply "PyPy is
cheating by comparing with an old Python 2.7.2": it is inside a thread
which started because "we didn't backport performance improvements to
2.7.x so far".

Just to convince myself, I just ran a performance comparison.  I ran
the same benchmark suite as speed.pypy.org, with 2.7.2 against 2.7.10,
both freshly compiled with no "configure" options at all.  The
differences are usually in the noise, but range from +5% to... -60%.
If anything, this seems to show that CPython should take more care
about performance regressions.  If someone is interested:

* "raytrace-simple" is 1.19 times slower
* "bm_mako" is 1.29 times slower
* "spitfire_cstringio" is 1.60 times slower
* a number of other benchmarks are around 1.08.

The "7.0x faster" number on speed.pypy.org would be significantly
*higher* if we upgraded the baseline to 2.7.10 now.


A bientôt,

Armin.