syslog alert message every 5 minute "reated slice user-0.slice" centos 7

Too many systemd: Created slice !

Installing the recent linux version seems to come with a default setting of flooding the /var/log/messages with entirely annoying duplicitous messages like:

systemd: Created slice user-0.slice.
systemd: Starting Session 1013 of user root.
systemd: Started Session 1013 of user root.
systemd: Created slice user-0.slice.
systemd: Starting Session 1014 of user root.
systemd: Started Session 1014 of user root

Edit:
#vi /etc/systemd/system.conf

then uncomment LogLevel and make it: LogLevel=notice

save and exit.

Then:

#systemctl restart rsyslog 
#systemd-analyze set-log-level notice