High memory usage by crio system.slice in RHOCP 4.x

Issue

• The processes of interactive sessions which got timed out and respective PIDs are not getting killed.
• High utilization of memory by crio.service system.slice:

Control Group                                                                Tasks   %CPU   Memory  Input/s Output/s
/system.slice/crio.service                                                    338    10.1   43.1G     -        -

• High number of abandoned processes by crio.service:

$ cat /sys/fs/cgroup/memory/system.slice/crio.service/cgroup.procs | wc -l
25

Note: CRI-O's internal stream-idle-timeout is 15 minutes. Make sure to double check output of above command at 15 minutes interval to make sure that is it the same issue.