On Fri, 13 Sep 2013 01:40:55 +0000 "Du, Yuyang" <yuyang.du@xxxxxxxxx> wrote: > Thank you. > > It turned out I did not understand snapshot, the new feature. > > Yes, I simply want a write to the buffer when the "tracing" begins and ends. John was right in this respect too. > > I think this makes sense (at least) for some cases. The traced is some states, and the delta of states matter. > I'm still not exactly sure what is needed, but you also have the trace_marker, that lets userspace apps (even "echo") write into the trace buffer. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html