Hi, all I've been trying to write a new configuration that a memory node is applied to the "cpuset.mems" but there is a problem for write. Here is what I've followed so far: 1. Change dax from device driver to memory [1] I applied a patch that dax can be turned into a system memory. It is already merged in v5.1. I actually have a physical Optane DC memory so currently, there are 3 online nodes on the system. # numactl --hardware available: 3 nodes (0-2) 2. Configure cgroup # mount -t cgroup2 none /sys/fs/cgroup # mkdir /sys/fs/cgroup/test # echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control # cat /sys/fs/cgroup/test/cpuset.mems.effective 0-2 # cat /sys/fs/cgroup/test/cpuset.mems <empty> The problem arises when I use a below command: # echo 0-2 > /sys/fs/cgroup/<cgroup_dir>/cpuset.mems bash: echo: write error: Invalid argument Apparently, node 2 has only memory which means it is cpu-less. I thought I can use any nodes that are written in cpuset.mems.effective but somehow the last cpu-less node cannot be used. Is this result expected? [1]: https://patchwork.kernel.org/cover/10829019/ Regards, Won-Kyo
