Comment 27 for bug 1638695

Matthias, I have made a series of pyperformance benchmarks [1] to compare the influence of the factors listed by Elvis on Xenial and Artful. All runs were done on the same machine (metal) with a fresh Ubuntu cloud image.

My observations confirm that both: changing fpectl and fPIC for _math.c module bring significant improvement over corresponding versions without the changes. I have replaced -fstack-protector-strong with -fstack-protector to observe even better results in the benchmark. Although in the examined scope it's impact is not as significant as the former 2 factors.

The combination of all three factors make the results close to what we can observe on Trusty.

I believe backporting the fpectl and _math.c changes also to Xenial is worth considering.
The -fstack-protector setting brings performance improvement, but it also creates some security doubts.

[1] http://pyperformance.readthedocs.io
[2] https://docs.google.com/spreadsheets/d/1R83NQ7xzIfzFMVdbrh-zqK_iBuPcuhWa6KdTYPibFmE/edit?usp=sharing