[lttng-dev] Beginner question: how to inspect scheduling of multi-threaded user application?

[David Aldrich]

Hi

I'm afraid I'm still struggling with getting started with lttng. To recap, I want to use lttng + TraceCompass to monitor the scheduling of threads in my multi-threaded C++ application on Ubuntu.

Here is my session:

$ sudo pkill lttng-sessiond
$ sudo lttng-sessiond
Error: Already running daemon.

$ lttng create demo_session Spawning a session daemon Session demo_session created.
Traces will be written in /home/<snip>/lttng-traces/demo_session-20160915-152653
<snip>:~$ PERROR [14956/14964]: bind inet: Address already in use (in lttcomm_bind_inet_sock() at inet.c:109)
Warning: An other session daemon is using this JUL port. JUL support will be deactivated not interfering with the tracing.

$ sudo lttng enable-event -k sched_switch -s demo_session
Error: Event sched_switch: Session name not found (channel channel0, session demo_session)
Warning: Some command(s) went wrong

As you can see, each of these command generated a warning or error.  Please will you suggest where I am going wrong?

Best regards

David