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

[Mohamad Gebai <mohamad.gebai@polymtl.ca>]

> 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