[root@f24m ~]# grep SLUB_DEBUG /boot/config-4.8.0-0.rc1.git0.1.fc25.x86_64
# CONFIG_SLUB_DEBUG_ON is not set
When I boot with slub_debug=1, I get this at boot time:
[ 0.000000] slub_debug option '1' unknown. skipped
says under Release section:
In addition, SLUB_DEBUG is enabled, but by default is inactive. You
need to boot with slub_debug=1 to make it perform its usual checks.
possible options, but I'm not sure which one(s) make it boot
functionally like a debug kernel.