tree e667cec0bba6e7678810ff0087c96547a21a45c7
parent 629ed0b10209ffc4e1d439e5508d52d5e3a090b8
author Tejun Heo <tj@kernel.org> 1333316324 -0700
committer Tejun Heo <tj@kernel.org> 1333316324 -0700

blkcg: cfq doesn't need per-cpu dispatch stats

blkio_group_stats_cpu is used to count dispatch stats using per-cpu
counters.  This is used by both blk-throtl and cfq-iosched but the
sharing is rather silly.

* cfq-iosched doesn't need per-cpu dispatch stats.  cfq always updates
  those stats while holding queue_lock.

* blk-throtl needs per-cpu dispatch stats but only service_bytes and
  serviced.  It doesn't make use of sectors.

This patch makes cfq add and use global stats for service_bytes,
serviced and sectors, removes per-cpu sectors counter and moves
per-cpu stat printing code to blk-throttle.c.

Signed-off-by: Tejun Heo <tj@kernel.org>