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Subject: Re: [Qemu-devel] [RFC PATCH v3 4/5] Update documentation for LTTng
	ust tracing
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To: =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>
Cc: qemu-devel@nongnu.org, Mohamad Gebai <mohamad.gebai@gmail.com>

On 13-10-16 08:05 AM, Alex Benn=C3=A9e wrote:
>>> 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).
> <snip>
>
> Hmm I've done both and I get nothing still. I can enable all tracepoint=
s
> though. This could just be a Ubuntu weirdness thing though.

That's weird. I did test it on a clean Ubuntu Precise (in a VM) and I=20
didn't have any problem after either one of these steps. Can you please=20
make sure that the user belongs to the "tracing" group and that the=20
lttng-sessiond daemon is running before running any instance of Qemu.=20
Also, Qemu should be running for LTTng to be able to list the events.

Does lttng enable-event -a -u/start/stop/view show any event?

>
> I'm not sure if mentioning the group/daemon requirements in the tracing
> doc is required though. I guess these things can be a little
> package/distro specific?
>
> '

This isn't really specific to Ubuntu, it's the setup of LTTng so I guess=20
I could add it to the documentation as well.

Thanks!
Mohamad