How to Limit memory for docker daemon and not for each container (but for total containers on a host)

How can we limit the memory usage for the total containers on RHEL7 VM? So not for each container but for all in total? We try it to add the MemoryMax line in the unit file for docker.service. We try to do it with cgroups but even then the containers use all the 65G of memory. Can someone help us please? THe OOM kills the processes and the linux team dont gonna disable the OOM because of the policy within the bank.