When looking at the geometric mean across the dozens of tests carried out, Linux 5.0 Git is clearly slower than its predecessors. With this box going back to Linux 4.12, keep in mind between Linux 4.14 and 4.15 is when Spectre/Meltdown came to light and began introducing in-kernel mitigations like PTI and Retpolines. But Linux 5.0 Git is clearly coming in as slower, which has been a similar outcome on other systems tested.
For a wide look at the kernel performance I have been running dozens of different benchmarks on each system, with some of the boxes going as far back as Linux 4.12 or the better part of two years ago. I've also taken the geometric mean of all tests successfully run on all tested kernel combinations and that's where it's clear Linux 5.0 is running slower than previous kernels...
I'll be running more tests through the weekend on more hardware and at least now having a few tests like Apache (with load via Siege), Sockperf, PostgreSQL, and others where they appear to be measurably slower on the new kernel for bisecting the issue to gain more insight on the Linux 5.0 performance. But overall there doesn't appear to be any very major, focused regression like we've seen in some of the past kernel series as a result of introducing new Spectre/Meltdown mitigations and other changes. Though with many of these apparent slowdowns being quite subtle could explain why the slower Linux 5.0 kernel performance has yet to be rectified unless it was another case like Linux 4.20 with STIBP where its original performance drop was sort of intentional albeit not properly communicated. Stay tuned for more tests.
tldr of this extensive benchmark is that linux 5.0 is performing worse in almost every metric. it's not substantial, but it's measurable.
<linus is letting garbage in now.
instead of calling people idiot's and telling them to fix their shit he's just letting it slide. linux will have a slow and painful death.