Kernel 4.14, Xfce DE.
After the today’s update [Stable Update] 2020-12-30 - Kernels, KDE, Cinnamon, LibreOffice, Python 3.9, Mesa 20.3.1 which also included systemd 247 (247.2-1)
in the journal logs, I see a new error/warning:
systemd[1004]: -.slice: Failed to migrate controller cgroups from /user.slice/user-1000.slice/user@1000.service, ignoring: Permission denied
After a quick research seems that to get rid of this error is needed this Grub parameter:
systemd.unified_cgroup_hierarchy=true
https://bbs.archlinux.org/viewtopic.php?id=261330
I added it and this error is gone.
I ask if is ok to use such parameter.