Can you check your custom kernel config, specifically if
CONFIG_CGROUP_CPUACCT=y
Probably easiest if you just use grep
grep CGROUP /boot/config-$(uname -r)
Done in another private email. Can copy here:
diff config-4.14.0-3-amd64 config-4.14.23 | grep CGROUP
< CONFIG_BLK_CGROUP=y
< # CONFIG_DEBUG_BLK_CGROUP is not set
< CONFIG_CGROUP_WRITEBACK=y
> # CONFIG_BLK_CGROUP is not set
< CONFIG_CGROUP_PIDS=y
> # CONFIG_CGROUP_PIDS is not set
< CONFIG_CGROUP_FREEZER=y
> # CONFIG_CGROUP_FREEZER is not set
< CONFIG_CGROUP_CPUACCT=y
< CONFIG_CGROUP_PERF=y
< # CONFIG_CGROUP_BPF is not set
> # CONFIG_CGROUP_CPUACCT is not set
> # CONFIG_CGROUP_PERF is not set
< CONFIG_SOCK_CGROUP_DATA=y
> # CONFIG_SOCK_CGROUP_DATA is not set
< CONFIG_NETFILTER_XT_MATCH_CGROUP=m
< CONFIG_NET_CLS_CGROUP=m
< CONFIG_CGROUP_NET_PRIO=y
< CONFIG_CGROUP_NET_CLASSID=y
> # CONFIG_CGROUP_NET_PRIO is not set
> # CONFIG_CGROUP_NET_CLASSID is not set
