tree ecd572867bfa5a82fa4ed16d7303448c7ea7d24c
parent 812d402648f4fc1ab1091b2172a46fc1b367c724
author Divyesh Shah <dpshah@google.com> 1270786510 -0700
committer Jens Axboe <jens.axboe@oracle.com> 1270794968 +0200

blkio: Add io_queued and avg_queue_size stats

These stats are useful for getting a feel for the queue depth of the cgroup,
i.e., how filled up its queues are at a given instant and over the existence of
the cgroup. This ability is useful when debugging problems in the wild as it
helps understand the application's IO pattern w/o having to read through the
userspace code (coz its tedious or just not available) or w/o the ability
to run blktrace (since you may not have root access and/or not want to disturb
performance).

Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>