2017-04-12 10:52 GMT+02:00 Victor Stinner <victor.stinner@gmail.com>:

I'm running benchmarks with this option. Once results will be ready, I will remove the old 2.7 result to replace it with the new one.

Done. speed.python.org now uses UCS-4 on Python 2.7. Is it better now?

Previous JSON file: https://github.com/haypo/performance_results/raw/master/2017-03-31-cpython/2...

New JSON file: https://github.com/haypo/performance_results/raw/master/2017-04-12-cpython/2...

I see small performance differences, but they don't seem to be related to UTF-16 => UCS-4, but more random noise. Comparison between the two files:

$ python3 -m perf compare_to 2017-03-31-cpython/2017-04-03_16-11-2.7-23d6eb656ec2.json.gz 2017-04-12-cpython/2017-04-10_17-27-2.7-e0cba5b45a5c.json.gz --table -G --min-speed=5 +-----------------+-----------------------------------+-----------------------------------+ | Benchmark | 2017-04-03_16-11-2.7-23d6eb656ec2 | 2017-04-10_17-27-2.7-e0cba5b45a5c | +=================+===================================+===================================+ | chameleon | 23.3 ms | 25.0 ms: 1.07x slower (+7%) | +-----------------+-----------------------------------+-----------------------------------+ | scimark_fft | 623 ms | 673 ms: 1.08x slower (+8%) | +-----------------+-----------------------------------+-----------------------------------+ | fannkuch | 806 ms | 889 ms: 1.10x slower (+10%) | +-----------------+-----------------------------------+-----------------------------------+ | scimark_sor | 401 ms | 443 ms: 1.11x slower (+11%) | +-----------------+-----------------------------------+-----------------------------------+ | unpack_sequence | 138 ns | 154 ns: 1.12x slower (+12%) | +-----------------+-----------------------------------+-----------------------------------+ | regex_v8 | 53.4 ms | 60.0 ms: 1.12x slower (+12%) | +-----------------+-----------------------------------+-----------------------------------+

Not significant (61): (...)

Hopefully, perf stores information on the Unicode implementation in metadata. You can check metadata using:

$ python3 -m perf 2017-03-31_06-53-2.7-5aa913d72317.json.gz -b 2to3|grep python_unicode

• python_unicode: UTF-16 $ python3 -m perf metadata 2017-04-10_17-27-2.7-e0cba5b45a5c.json.gz -b 2to3|grep python_unicode
• python_unicode: UCS-4

Victor