[Stable Update] 2020-12-30 and systemd 247: a new error - cgroups related - appeared in the log

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:

I added it and this error is gone.
I ask if is ok to use such parameter.

Is the warning still present if you boot with the parameter systemd.unified_cgroup_hierarchy=true

Related commit is https://github.com/systemd/systemd/comm … 20a1d8ec67