[PATCH v3 10/11] block-throttle: add a simple idle detection

A cgroup gets assigned a high limit, but the cgroup could never dispatch enough IO to cross the high limit. In such case, the queue state machine will remain in LIMIT_HIGH state and all other cgroups will be throttled according to high limit. This is unfair for other cgroups. We should treat the

[PATCH v3 10/11] block-throttle: add a simple idle detection

A cgroup gets assigned a high limit, but the cgroup could never dispatch enough IO to cross the high limit. In such case, the queue state machine will remain in LIMIT_HIGH state and all other cgroups will be throttled according to high limit. This is unfair for other cgroups. We should treat the