[lttng-dev] session create failed

[Lingyu Zhu]

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.

 On Wed, Mar 19, 2014 at 1:11 AM, Jonathan Rajotte <
> jonathan.r.julien at gmail.com> wrote:
>
>> AFAIK if you want to use kernel tracing as a regular user you need:
>> 1)  to be part of a tracing user group (default: tracing [1])
>> 2) sessiond must be started by root
>>
>> you can use "sudo lttng-sessiond -d" before doing any lttng related tasks
>> and/or you can add sessiond to your boot sequence.
>>
>> [1] you might need to create it, you can also use another group via
>> lttng-sessiond -g <group_name>
>>
>>
>> On Tue, Mar 18, 2014 at 12:53 PM, Lingyu Zhu <lynuszhu at gmail.com> wrote:

>
>>
>>  On Wed, Mar 19, 2014 at 12:35 AM, Jonathan Rajotte <
>> jonathan.r.julien at gmail.com> wrote:
>>
>>> Hi Lingyu,
>>>
>>>   Does a sessiond is created on boot ?
>>>> You can check via htop and filter for lttng or sessiond.
>>>>
>>> No sessiond is created on boot before I do these operations.
>>> what else info should I provide?
>>>
>>>
>>>
>>>  On Tue, Mar 18, 2014 at 12:31 PM, Lingyu Zhu <lynuszhu at gmail.com>wrote:
>>>
>>>>   Hello,
>>>> Sorry for being away a few days. My thesis opening proposal is hiting
>>>> the deadline, which happens to be same date for GSoC. Now I can be fully
>>>> devoted to lttng and compose my GSoC proposal.
>>>>
>>>> Anyway, I may have found a bug.I'm not very sure. Here is my log:
>>>>
>>>> ===================================================
>>>>  [lynus at slave1 ~]$lttng create
>>>> Spawning a session daemon
>>>> Session auto-20140319-081547 created.
>>>> Traces will be written in /home/lynus/lttng-traces/auto-20140319-081547
>>>> [lynus at slave1 ~]$ lttng enable-event page_block -k
>>>> Error: Event page_block: Tracing the kernel requires a root
>>>> lttng-sessiond daemon, as well as "tracing" group membership or root user
>>>> ID for the lttng client. (channel channel0, session auto-20140319-081547)
>>>> Warning: Some command(s) went wrong
>>>> [lynus at slave1 ~]$ lttng destroy
>>>> Session auto-20140319-081547 destroyed
>>>> [lynus at slave1 ~]$ sudo su -
>>>> [sudo] password for lynus:
>>>> root at slave1:~# lttng create
>>>> Spawning a session daemon
>>>> Warning: No tracing group detected
>>>> Session auto-20140319-081615 created.
>>>> Traces will be written in /root/lttng-traces/auto-20140319-081615
>>>> PERROR [4774/4882]: 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.
>>>> root at slave1:~# lttng create
>>>> Session auto-20140319-081620 created.
>>>> Traces will be written in /root/lttng-traces/auto-20140319-081620
>>>> root at slave1:~#
>>>> [END] 2014/3/19 0:04:31
>>>> ======================================================
>>>>
>>>> These command is issued right after my machine is booted. And it failed
>>>> every time if I try to enable kernel event as non-root user first then
>>>> switch to root to create session.  If I directly switch to root and create
>>>> a seesion, everything is normal. So I guess I may have come across a bug.
>>>> Any comment?
>>>>
>>>> _______________________________________________
>>>> lttng-dev mailing list
>>>> lttng-dev at lists.lttng.org
>>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>
>>>>
>>>
>>>
>>> --
>>> Jonathan Rajotte Julien
>>> Chargé de laboratoire, INF1995
>>> Polytechnique Montréal
>>>
>>
>>
>
>
> --
> Jonathan Rajotte Julien
> Chargé de laboratoire, INF1995
> Polytechnique Montréal
>
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