Quoting Andy Lutomirski (2017-09-06 06:13:39) > I'm running e7d0c41ecc2e372a81741a30894f556afec24315 from Linus' tree > today, and I'm seeing abysmal scheduler performance. Running make -j4 > ends up with all the tasks on CPU 3 most of the time (on my > 4-logical-thread laptop). taskset -c 0 whatever puts whatever on CPU > 0, but plain while true; do true; done puts the infinite loop on CPU 3 > right along with the make -j4 tasks. > > This is on Fedora 26, and I don't think I'm doing anything weird. > systemd has enabled the cpu controller, but it doesn't seem to have > configured anything or created any non-root cgroups. > > Just a heads up. I haven't tried to diagnose it at all.
There is an issue on !llc machines arising from numa_wake_wide() where processes are not spread widely across the low-power cores: https://patchwork.kernel.org/patch/9875581/ The patch we are using to fix the regression is https://cgit.freedesktop.org/drm-intel/commit/?h=topic/core-for-CI&id=6c362d9657293d700a8299acbeb2f1e24378f488 -Chris
