-drivers/base/topology.c, is to export the 6 or 9 attributes. The three book
-related sysfs files will only be created if CONFIG_SCHED_BOOK is selected.
+drivers/base/topology.c, is to export the 6 to 12 attributes. The book
+and drawer related sysfs files will only be created if CONFIG_SCHED_BOOK
+and CONFIG_SCHED_DRAWER are selected.
+
+CONFIG_SCHED_BOOK and CONFIG_DRAWER are currently only used on s390, where
+they reflect the cpu and cache hierarchy.