- CFQ will handle the hierarchy correctly but and throttling will
- practically treat all groups at same level. For details on CFQ
- hierarchy support, refer to Documentation/block/cfq-iosched.txt.
- Throttling will treat the hierarchy as if it looks like the
- following.
+CFQ by default and throttling with "sane_behavior" will handle the
+hierarchy correctly. For details on CFQ hierarchy support, refer to
+Documentation/block/cfq-iosched.txt. For throttling, all limits apply
+to the whole subtree while all statistics are local to the IOs
+directly generated by tasks in that cgroup.
+
+Throttling without "sane_behavior" enabled from cgroup side will
+practically treat all groups at same level as if it looks like the
+following.