block: Update to io-controller stats

Changelog from v1:
o Call blkiocg_update_idle_time_stats() at cfq_rq_enqueued() instead of at
  dispatch time.

Changelog from original patchset: (in response to Vivek Goyal's comments)
o group blkiocg_update_blkio_group_dequeue_stats() with other DEBUG functions
o rename blkiocg_update_set_active_queue_stats() to
  blkiocg_update_avg_queue_size_stats()
o s/request/io/ in blkiocg_update_request_add_stats() and
  blkiocg_update_request_remove_stats()
o Call cfq_del_timer() at request dispatch() instead of
  blkiocg_update_idle_time_stats()

Signed-off-by: Divyesh Shah<dpshah@google.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/blk-cgroup.c

@@ -202,7 +202,7 @@ void blkiocg_update_idle_time_stats(struct blkio_group *blkg)
 }
 EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats);
 
-void blkiocg_update_set_active_queue_stats(struct blkio_group *blkg)
+void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
 {
 	unsigned long flags;
 	struct blkio_group_stats *stats;
@@ -216,14 +216,21 @@ void blkiocg_update_set_active_queue_stats(struct blkio_group *blkg)
 	blkio_update_group_wait_time(stats);
 	spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
-EXPORT_SYMBOL_GPL(blkiocg_update_set_active_queue_stats);
+EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
+
+void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+			unsigned long dequeue)
+{
+	blkg->stats.dequeue += dequeue;
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
 #else
 static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg,
 					struct blkio_group *curr_blkg) {}
 static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {}
 #endif
 
-void blkiocg_update_request_add_stats(struct blkio_group *blkg,
+void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 			struct blkio_group *curr_blkg, bool direction,
 			bool sync)
 {
@@ -236,9 +243,9 @@ void blkiocg_update_request_add_stats(struct blkio_group *blkg,
 	blkio_set_start_group_wait_time(blkg, curr_blkg);
 	spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
-EXPORT_SYMBOL_GPL(blkiocg_update_request_add_stats);
+EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
 
-void blkiocg_update_request_remove_stats(struct blkio_group *blkg,
+void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 						bool direction, bool sync)
 {
 	unsigned long flags;
@@ -248,7 +255,7 @@ void blkiocg_update_request_remove_stats(struct blkio_group *blkg,
 					direction, sync);
 	spin_unlock_irqrestore(&blkg->stats_lock, flags);
 }
-EXPORT_SYMBOL_GPL(blkiocg_update_request_remove_stats);
+EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
 
 void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
 {
@@ -636,15 +643,6 @@ SHOW_FUNCTION_PER_GROUP(empty_time, BLKIO_STAT_EMPTY_TIME, 0);
 #endif
 #undef SHOW_FUNCTION_PER_GROUP
 
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
-			unsigned long dequeue)
-{
-	blkg->stats.dequeue += dequeue;
-}
-EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
-#endif
-
 static int blkio_check_dev_num(dev_t dev)
 {
 	int part = 0;

block/blk-cgroup.h

@@ -169,7 +169,7 @@ static inline char *blkg_path(struct blkio_group *blkg)
 {
 	return blkg->path;
 }
-void blkiocg_update_set_active_queue_stats(struct blkio_group *blkg);
+void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
 void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 				unsigned long dequeue);
 void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
@@ -198,7 +198,7 @@ BLKG_FLAG_FNS(empty)
 #undef BLKG_FLAG_FNS
 #else
 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
-static inline void blkiocg_update_set_active_queue_stats(
+static inline void blkiocg_update_avg_queue_size_stats(
 						struct blkio_group *blkg) {}
 static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
 						unsigned long dequeue) {}
@@ -226,9 +226,9 @@ void blkiocg_update_completion_stats(struct blkio_group *blkg,
 	uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
 void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 					bool sync);
-void blkiocg_update_request_add_stats(struct blkio_group *blkg,
+void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 		struct blkio_group *curr_blkg, bool direction, bool sync);
-void blkiocg_update_request_remove_stats(struct blkio_group *blkg,
+void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 					bool direction, bool sync);
 #else
 struct cgroup;
@@ -253,9 +253,9 @@ static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
 		bool sync) {}
 static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
 						bool direction, bool sync) {}
-static inline void blkiocg_update_request_add_stats(struct blkio_group *blkg,
+static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
 		struct blkio_group *curr_blkg, bool direction, bool sync) {}
-static inline void blkiocg_update_request_remove_stats(struct blkio_group *blkg,
+static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
 						bool direction, bool sync) {}
 #endif
 #endif /* _BLK_CGROUP_H */

block/cfq-iosched.c

@@ -1381,10 +1381,10 @@ static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
 {
 	elv_rb_del(&cfqq->sort_list, rq);
 	cfqq->queued[rq_is_sync(rq)]--;
-	blkiocg_update_request_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+	blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
 						rq_is_sync(rq));
 	cfq_add_rq_rb(rq);
-	blkiocg_update_request_add_stats(
+	blkiocg_update_io_add_stats(
 			&cfqq->cfqg->blkg, &cfqq->cfqd->serving_group->blkg,
 			rq_data_dir(rq), rq_is_sync(rq));
 }
@@ -1442,7 +1442,7 @@ static void cfq_remove_request(struct request *rq)
 	cfq_del_rq_rb(rq);
 
 	cfqq->cfqd->rq_queued--;
-	blkiocg_update_request_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+	blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
 						rq_is_sync(rq));
 	if (rq_is_meta(rq)) {
 		WARN_ON(!cfqq->meta_pending);
@@ -1541,7 +1541,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
 	if (cfqq) {
 		cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
 				cfqd->serving_prio, cfqd->serving_type);
-		blkiocg_update_set_active_queue_stats(&cfqq->cfqg->blkg);
+		blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
 		cfqq->slice_start = 0;
 		cfqq->dispatch_start = jiffies;
 		cfqq->allocated_slice = 0;
@@ -2395,11 +2395,6 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
 	}
 
 	cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
-	/*
-	 * This is needed since we don't exactly match the mod_timer() and
-	 * del_timer() calls in CFQ.
-	 */
-	blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
 	return 1;
 }
 
@@ -3208,8 +3203,11 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 				cfq_del_timer(cfqd, cfqq);
 				cfq_clear_cfqq_wait_request(cfqq);
 				__blk_run_queue(cfqd->queue);
-			} else
+			} else {
+				blkiocg_update_idle_time_stats(
+						&cfqq->cfqg->blkg);
 				cfq_mark_cfqq_must_dispatch(cfqq);
+			}
 		}
 	} else if (cfq_should_preempt(cfqd, cfqq, rq)) {
 		/*
@@ -3235,7 +3233,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
 	list_add_tail(&rq->queuelist, &cfqq->fifo);
 	cfq_add_rq_rb(rq);
 
-	blkiocg_update_request_add_stats(&cfqq->cfqg->blkg,
+	blkiocg_update_io_add_stats(&cfqq->cfqg->blkg,
 			&cfqd->serving_group->blkg, rq_data_dir(rq),
 			rq_is_sync(rq));
 	cfq_rq_enqueued(cfqd, cfqq, rq);