Comment 8 for bug 1638695

Hello,

I am in the process of verifying this performance regression on a 16.04 Xenial machine using the kernel Linux-4.4.0-38.

I ran a locally compiled python 2.7.12 version built with different versions of GCC, 5.3.1 (current) and 4.8.0 both coming from the Ubuntu archives.

The benchmark suite I am using is the pyperformance suite (https://github.com/python/performance), I am running the full test suite, using the following command:

$ pyperformance run --python=python2 -o xxx.json

According to the latest test run i did using Python 2.7.12/GCC 4.8 (using GCC 5.3.1 as the baseline), 50% of the tests (32/64) have a significant variance in performance from which 19/32 are slower (in times ranging from 5-15%).

Just for information, I am comparing results using the following command:

$ pyperformance compare python-2.7.12-gcc-5.3.1.json python-2.7.12-gcc-4.8.0.json

I am attaching here the current comparison results for analysis.