io_uring: add completion trace event

We currently don't have a completion event trace, add one of those. And
to better be able to match up submissions and completions, add user_data
to the submission trace as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -592,6 +592,8 @@ static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data,
 {
 	struct io_uring_cqe *cqe;
 
+	trace_io_uring_complete(ctx, ki_user_data, res);
+
 	/*
 	 * If we can't get a cq entry, userspace overflowed the
 	 * submission (by quite a lot). Increment the overflow count in
@@ -2733,7 +2735,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
 		s.has_user = *mm != NULL;
 		s.in_async = true;
 		s.needs_fixed_file = true;
-		trace_io_uring_submit_sqe(ctx, true, true);
+		trace_io_uring_submit_sqe(ctx, s.sqe->user_data, true, true);
 		io_submit_sqe(ctx, &s, statep, &link);
 		submitted++;
 	}
@@ -2913,7 +2915,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit,
 		s.needs_fixed_file = false;
 		s.ring_fd = ring_fd;
 		submit++;
-		trace_io_uring_submit_sqe(ctx, true, false);
+		trace_io_uring_submit_sqe(ctx, s.sqe->user_data, true, false);
 		io_submit_sqe(ctx, &s, statep, &link);
 	}
 

include/trace/events/io_uring.h

@@ -284,10 +284,43 @@ TRACE_EVENT(io_uring_fail_link,
 	TP_printk("request %p, link %p", __entry->req, __entry->link)
 );
 
+/**
+ * io_uring_complete - called when completing an SQE
+ *
+ * @ctx:		pointer to a ring context structure
+ * @user_data:		user data associated with the request
+ * @res:		result of the request
+ *
+ */
+TRACE_EVENT(io_uring_complete,
+
+	TP_PROTO(void *ctx, u64 user_data, long res),
+
+	TP_ARGS(ctx, user_data, res),
+
+	TP_STRUCT__entry (
+		__field(  void *,	ctx		)
+		__field(  u64,		user_data	)
+		__field(  long,		res		)
+	),
+
+	TP_fast_assign(
+		__entry->ctx		= ctx;
+		__entry->user_data	= user_data;
+		__entry->res		= res;
+	),
+
+	TP_printk("ring %p, user_data 0x%llx, result %ld",
+			  __entry->ctx, (unsigned long long)__entry->user_data,
+			  __entry->res)
+);
+
+
 /**
  * io_uring_submit_sqe - called before submitting one SQE
  *
- * @ctx:			pointer to a ring context structure
+ * @ctx:		pointer to a ring context structure
+ * @user_data:		user data associated with the request
  * @force_nonblock:	whether a context blocking or not
  * @sq_thread:		true if sq_thread has submitted this SQE
  *
@@ -296,24 +329,27 @@ TRACE_EVENT(io_uring_fail_link,
  */
 TRACE_EVENT(io_uring_submit_sqe,
 
-	TP_PROTO(void *ctx, bool force_nonblock, bool sq_thread),
+	TP_PROTO(void *ctx, u64 user_data, bool force_nonblock, bool sq_thread),
 
-	TP_ARGS(ctx, force_nonblock, sq_thread),
+	TP_ARGS(ctx, user_data, force_nonblock, sq_thread),
 
 	TP_STRUCT__entry (
-		__field(  void *,	ctx				)
+		__field(  void *,	ctx		)
+		__field(  u64,		user_data	)
 		__field(  bool,		force_nonblock	)
-		__field(  bool,		sq_thread		)
+		__field(  bool,		sq_thread	)
 	),
 
 	TP_fast_assign(
-		__entry->ctx			= ctx;
+		__entry->ctx		= ctx;
+		__entry->user_data	= user_data;
 		__entry->force_nonblock	= force_nonblock;
-		__entry->sq_thread		= sq_thread;
+		__entry->sq_thread	= sq_thread;
 	),
 
-	TP_printk("ring %p, non block %d, sq_thread %d",
-			  __entry->ctx, __entry->force_nonblock, __entry->sq_thread)
+	TP_printk("ring %p, user data 0x%llx, non block %d, sq_thread %d",
+			  __entry->ctx, (unsigned long long) __entry->user_data,
+			  __entry->force_nonblock, __entry->sq_thread)
 );
 
 #endif /* _TRACE_IO_URING_H */