On Wed, 2017-02-08 at 15:32 -0500, Steven Rostedt wrote:

On Wed,  8 Feb 2017 11:24:59 -0600
Tom Zanussi [off-list ref] wrote:

...

quoted

 	/*
 	 * The event first in the commit queue updates the
 	 * time stamp.

@@ -2492,8 +2516,7 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
 			delta <<= TS_SHIFT;
 			delta += event->time_delta;
 			cpu_buffer->write_stamp += delta;
-		} else
-			cpu_buffer->write_stamp += event->time_delta;
+		}

And why is this removed?

Yeah, it doesn't make sense, given that we've returned already.  Looks
like it was just a lineo..

quoted

 	}
 }
 

@@ -2674,7 +2697,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
 	 * If this is the first commit on the page, then it has the same
 	 * timestamp as the page itself.
 	 */
-	if (!tail)
+	if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
 		info->delta = 0;
 
 	/* See if we shot pass the end of this buffer page */

@@ -2752,8 +2775,11 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
 	/* make sure this diff is calculated here */
 	barrier();
 
-	/* Did the write stamp get updated already? */
-	if (likely(info.ts >= cpu_buffer->write_stamp)) {
+	if (ring_buffer_time_stamp_abs(buffer)) {
+		info.delta = info.ts;
+		rb_handle_timestamp(cpu_buffer, &info);
+	} else /* Did the write stamp get updated already? */
+		if (likely(info.ts >= cpu_buffer->write_stamp)) {

OK, please break this patch up into two. Although, I may take it and
start on it as well ;-)  One with the implementation of the EXTEND_ABS,
and the other with the setting of the flags.

OK, I'll break it up if I don't see you do anything with it in the
meantime..

Tom