hyper-v: trace vmbus_release_relid()

Add tracepoint to CHANNELMSG_RELID_RELEASED sender.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/channel_mgmt.c

@@ -373,12 +373,15 @@ static void percpu_channel_deq(void *arg)
 static void vmbus_release_relid(u32 relid)
 {
 	struct vmbus_channel_relid_released msg;
+	int ret;
 
 	memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
 	msg.child_relid = relid;
 	msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
-	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released),
-		       true);
+	ret = vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released),
+			     true);
+
+	trace_vmbus_release_relid(&msg, ret);
 }
 
 void hv_process_channel_removal(u32 relid)

drivers/hv/hv_trace.h

@@ -258,6 +258,22 @@ TRACE_EVENT(vmbus_negotiate_version,
 		    )
 	);
 
+TRACE_EVENT(vmbus_release_relid,
+	    TP_PROTO(const struct vmbus_channel_relid_released *msg, int ret),
+	    TP_ARGS(msg, ret),
+	    TP_STRUCT__entry(
+		    __field(u32, child_relid)
+		    __field(int, ret)
+		    ),
+	    TP_fast_assign(
+		    __entry->child_relid = msg->child_relid;
+		    __entry->ret = ret;
+		    ),
+	    TP_printk("sending child_relid 0x%x, ret %d",
+		      __entry->child_relid, __entry->ret
+		    )
+	);
+
 #undef TRACE_INCLUDE_PATH
 #define TRACE_INCLUDE_PATH .
 #undef TRACE_INCLUDE_FILE