block: fixup block IO unplug trace call

It was removed with the on-stack plugging, readd it and track the
depth of requests added when flushing the plug.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 43a985390bb6..006e60b58306 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -401,9 +401,9 @@ TRACE_EVENT(block_plug,
 
 DECLARE_EVENT_CLASS(block_unplug,
 
-        TP_PROTO(struct request_queue *q),
+        TP_PROTO(struct request_queue *q, unsigned int depth),
 
-        TP_ARGS(q),
+        TP_ARGS(q, depth),
 
         TP_STRUCT__entry(
                 __field( int,           nr_rq                   )
@@ -411,7 +411,7 @@ DECLARE_EVENT_CLASS(block_unplug,
         ),
 
         TP_fast_assign(
-                __entry->nr_rq  = q->rq.count[READ] + q->rq.count[WRITE];
+                __entry->nr_rq = depth;
                 memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
         ),
 
@@ -421,15 +421,16 @@ DECLARE_EVENT_CLASS(block_unplug,
 /**
  * block_unplug_io - release of operations requests in request queue
  * @q: request queue to unplug
+ * @depth: number of requests just added to the queue
  *
  * Unplug request queue @q because device driver is scheduled to work
  * on elements in the request queue.
  */
 DEFINE_EVENT(block_unplug, block_unplug_io,
 
-        TP_PROTO(struct request_queue *q),
+        TP_PROTO(struct request_queue *q, unsigned int depth),
 
-        TP_ARGS(q)
+        TP_ARGS(q, depth)
 );
 
 /**