On Fri, 23 Sep 2016 01:19:54 +0200 Victor Stinner victor.stinner@gmail.com wrote:

While analyzing a performance regression ( http://bugs.python.org/issue28243 ) , I had a major issue with my benchmark. Suddenly, for no reason, after 30 minutes of benchmarking, the benchmark became 2x FASTER...

Did the benchmark really become 2x faster, or did the clock become 2x slower?

If you found a magic knob in your CPU that suddently makes it 2x faster, many people would probably like to hear about it ;-)

If you have an Intel CPU, use Linux, have a CPU with multiple physical cores and have 15 minutes to run a test, I would appreciate if you can try to reproduce the bug!

Can you tell us how to "reproduce"?

Regards

Antoine.