I've just had similar problems (Raspbian Stretch 9.4, kernel 4.14.34-v7+), but cgroup_enable=memory worked for me. Full contents of my /boot/cmdline.txt are: dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=PARTUUID=66b0b034-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait ...