On Wed, Feb 8, 2017 at 12:59 AM, Victor Stinner <victor.stinner@gmail.com> wrote:

Hi,

FYI CPython 3.7 is now faster than CPython 2.7 on most benchmarks. It would be interesting to investigate why 12 benchmarks are still slower to check if we missed something obvious.

Comparison, ignoring differences smaller than 10%:

haypo@speed-python$ python3 -m perf compare_to 2017-01-03_11-17-2.7-5988caffbff9.json 2017-02-06_07-15-default-e06af4027546.json -G --min-speed=10 Slower (12):

• python_startup_no_site: 3.11 ms +- 0.02 ms -> 8.33 ms +- 0.04 ms: 2.68x slower (+168%)
• python_startup: 6.42 ms +- 0.04 ms -> 14.1 ms +- 0.1 ms: 2.20x slower (+120%)

The top two slower benchmark is startup. There are some unavoidable reasons (io, importlib, and more rich types based on abc). But I sent two pull requests reduce cost of site.py.

• http://bugs.python.org/issue29585
• http://bugs.python.org/issue29592

If they are merged, (python_startup - python_startup_no_site) will be very close to Python 2.7.

For more optimization, I think we need to write some function in C for importlib.