Comment 15 for bug 1663280

I just rerun all the tests again on F24 and F25. I can confirm that the performance issue disappears on F25 when glibc package gets updated to version 2.24-4. It is still observable on F24 because the fix has not been propagated there. I'm very sorry for such a stupid mistake (not updating livecd packages before running tests). Thanks to Marcel for pointing that out, it saved me huge amount of time.

We also did some kind of investigation regarding specific CPU models which suffer from such kind of performance degradation. Quite reliable source [1] says that 'AMD processors and later Intel processors (Skylake and Knights Landing) do not have such a state switch'. It means that only Sandy Bridge, Ivy Bridge, Haswell, and Broadwell CPUs are affected.

Many thanks to Carlos and Florian for such fast and straight to the point response. I really appreciate that.

[1] http://www.agner.org/optimize/blog/read.php?i=761#761