Re: [Qemu-devel] [RFC PATCH v3 4/5] Update documentation for LTTng ust tracing

[Mohamad Gebai]

> Running this gives me:
>
> <quote>
> UST events:
> -------------
> None
> </quote>
>
> Before or after running qemu. What is the mechanism lttng expects to
> find out all these events?

Either the user should belong the group "tracing", or launch the 
lttng-sessiond daemon (lttng-sessiond -d).

> > +
> > +Create tracing session:
> > +
> > +    lttng create mysession
> > +
> > +Enable events:
> > +
> > +    lttng enable-event qemu:g_malloc -u
> > +
> > +Where the events can either be a comma-separated list of events, or "-a" to
> > +enable all tracepoint events. Start and stop tracing as needed:
> > +
> > +    lttng start
> > +    lttng stop
> > +
> > +View the trace:
> > +
> > +    lttng view
> > +
> > +Destroy tracing session:
> > +
> > +    lttng destroy
> > +
> > +Babeltrace can be used at any later time to view the trace:
> > +
> > +    babeltrace $HOME/lttng-traces/mysession-<date>-<time>
> > +
> The rest of this looks OK and worked on my system.
>
> >   === SystemTap ===
> >   
> >   The "dtrace" backend uses DTrace sdt probes but has only been tested with
Thanks!
Mohamad