Hello, Le 03/03/2017 à 08:27, Nick Coghlan a écrit :
On 2 March 2017 at 07:00, Victor Stinner <victor.stinner@gmail.com <mailto:victor.stinner@gmail.com>> wrote:
Hi,
Your document doesn't explain how you configured the host to run benchmarks. Maybe you didn't tune Linux or anything else? Be careful with modern hardware which can make funny (or not) surprises.
Victor, do you know if you or anyone else has compared the RHEL/CentOS 7.x binaries (Python 2.7.5 + patches, built with GCC 4.8.x) with the Fedora 25 binaries (Python 2.7.13 + patches, built with GCC 6.3.x)?
I know you've been using perf to look for differences between *Python* major versions, but this would be more about using Python's benchmark suite to investigate the performance of *gcc*, since it appears that may be the culprit here.
Cheers, Nick.
Out of curiosity, I ran the set of benchmarks in two LXC containers running centos7 (2.7.5 + gcc 4.8.5) and Fedora 25 (2.7.13 + gcc 6.3.x). The benchmarks do run faster in 18 benchmarks, slower on 12 and insignificant for the rest (~33 from memory). Do take into account that this is run on baremetal system running an Ubuntu kernel (4.4.0-59) so this is by no mean a reference value but just for a quick test. Results were appended to the spreadsheet referred to in the analysis document. It is somewhat coherent with a previous test I ran where I disabled PGO on 2.7.6+gcc4.8 (Trusty). This made the 2.7.6+gcc4.8 (Trusty) interpreter to become slower than the Xenial reference. Unfortunately, I cannot redeploy my server on RHEL or Fedora at the moment so this is as far as I can go. Kind regards, ...Louis -- Louis Bouchard Software engineer, Cloud & Sustaining eng. Canonical Ltd Ubuntu developer Debian Maintainer GPG : 429D 7A3B DD05 B6F8 AF63 B9C4 8B3D 867C 823E 7A61