http://bugzilla.suse.com/show_bug.cgi?id=1088382 Bug ID: 1088382 Summary: Heavy performance loss since update mid-March Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: x86-64 OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kernel Assignee: kernel-maintainers@forge.provo.novell.com Reporter: Michael.Zapf@web.de QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- On three different desktop PCs I noticed a heavy performance loss since about mid March. The strange thing is that while this happened for all three of them, it was at different kernel releases, so maybe it is not the kernel but something else. The performance loss got obvious while I was working on MAME, the emulation framework. When you start it with the option "-bench <n>", it deactivates the screen output (just empty window frame) and deactivates all timing delays, thus running as fast as possible. I am getting this output when I boot the current kernel: Linux capella.daheim.lan 4.15.13-1-default #1 SMP PREEMPT Sun Mar 25 08:34:58 UTC 2018 (950fc49) x86_64 x86_64 x86_64 GNU/Linux Average speed: 302.08% (19 seconds) However, when I boot the kernel 4.15.10, I am getting this: Linux capella.daheim.lan 4.15.10-1-default #1 SMP PREEMPT Thu Mar 15 20:31:17 UTC 2018 (5e4329c) x86_64 x86_64 x86_64 GNU/Linux Average speed: 896.21% (19 seconds) which is the speed that I had expected. The CPU is an i7-6700K. This output is not an artifact; it is well observable during running the emulation (e.g. chopped sound). Also, oither programs suffer from a similar performance loss. I am using the Leawo Bluray Player running in Wine; this is not possible anymore - the framerate drops to a crawl. Just by booting the older kernel (4.15.10), the performance is back again. As said, I could verify this performance loss on three different PCs, but interestingly, not on two laptops that I also installed Tumbleweed on. On those three PCs, the critical point in time seems different. I can say for sure that by the end of February (also with the old style of Tumbleweed splash screen), all systems ran fast (I can reproduce that by rolling back), and that by 4.15.13, all systems (except the laptops) slowed down. I will try a clean install on a spare SSD to see whether this can be reproduced on a newly installed system. I should add that I already tried to remove my AMD RX480 card to rule out amdgpu influence, so I temporarily used the onboard graphics. This had no effect on the observation. Also, kernel boot parameters "nopti" and "nospec" had no effect. -- You are receiving this mail because: You are on the CC list for the bug.