[lttng-dev] session create failed

[Thibault, Daniel]

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Date: Wed, 19 Mar 2014 01:19:52 +0800
From: Lingyu Zhu <lynuszhu at gmail.com>
To: Jonathan Rajotte <jonathan.r.julien at gmail.com>

> Thanks for point that out. But My point is creating session would fail as
> root, only after I  failed enable kernel event as normal user.

   Your session creation remains successful.  You just can't do kernel tracing from it.  You could have gone on to enable user-space events, etc.

   The later JUL problem is because you did not 'kill' the local session daemon the first lttng command spawned.

   In a nutshell, use 'lttng <command>' for local user-space tracing, 'sudo -H lttng <command>' for kernel and multiple user-space tracing.  Alternately, join the 'tracing' group (log off and back on for the change to take), then use 'lttng <command>' for all tracing -but make sure the root daemon is the only lttng session daemon running.

   As late as lttng 2.3, the lttng -g option does not work.  Has it been fixed?

Daniel U. Thibault
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