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>

1 files changed, 6 insertions, 6 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 0b0a176ee007..c82de47ae69f 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -65,6 +65,10 @@ struct blkg_rwstat {
 };
 
 struct blkio_group_stats {
+        /* total bytes transferred */
+        struct blkg_rwstat              service_bytes;
+        /* total IOs serviced, post merge */
+        struct blkg_rwstat              serviced;
         /* number of ios merged */
         struct blkg_rwstat              merged;
         /* total time spent on device in ns, may not be accurate w/ queueing */
@@ -73,6 +77,8 @@ struct blkio_group_stats {
         struct blkg_rwstat              wait_time;
         /* number of IOs queued up */
         struct blkg_rwstat              queued;
+        /* total sectors transferred */
+        struct blkg_stat                sectors;
         /* total disk time and nr sectors dispatched by this group */
         struct blkg_stat                time;
 #ifdef CONFIG_DEBUG_BLK_CGROUP
@@ -104,8 +110,6 @@ struct blkio_group_stats_cpu {
         struct blkg_rwstat              service_bytes;
         /* total IOs serviced, post merge */
         struct blkg_rwstat              serviced;
-        /* total sectors transferred */
-        struct blkg_stat                sectors;
 };
 
 struct blkio_group_conf {
@@ -183,10 +187,6 @@ int blkcg_print_stat(struct cgroup *cgrp, struct cftype *cft,
                      struct seq_file *sf);
 int blkcg_print_rwstat(struct cgroup *cgrp, struct cftype *cft,
                        struct seq_file *sf);
-int blkcg_print_cpu_stat(struct cgroup *cgrp, struct cftype *cft,
-                         struct seq_file *sf);
-int blkcg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
-                           struct seq_file *sf);
 
 struct blkg_conf_ctx {
         struct gendisk          *disk;