> I think Tejun is concerned about a change in the default behavior of > cpuset v1. > > There is a special v2 mode for cpuset that is enabled by the mount > option "cpuset_v2_mode". This causes the cpuset v1 to adopt some of the > v2 behavior. I introduced this v2 mode a while back to address, I think, > a similar concern. Could you try that to see if it is able to address > your problem? If not, you can make some code adjustment within the > framework of the v2 mode. As long as it is an opt-in, I think we are > open to further change. I am also able to reproduce on Ubuntu 21.04 LTS. all docker will be put in this cgroups and its child cgroups: /sys/fs/cgroup/cpuset/docker disabling and enabling SMT by: echo off > /sys/devices/system/cpu/smt/control echo on > /sys/devices/system/cpu/smt/control or unpluging and pluging CPUs by: echo 0 > /sys/devices/system/cpu/cpuX/online echo 1 > /sys/devices/system/cpu/cpuX/online then all docker images will lose some CPUs. So should we document the broken behaviours somewhere? Thanks barry
