[lttng-dev] beginner question

Alexandre Montplaisir alexandre.montplaisir at polymtl.ca
Sat May 5 00:49:15 EDT 2012

On 12-05-05 12:42 AM, Julien Desfossez wrote:
> Hi,
> On 05/05/12 12:14 AM, Loris Degioanni wrote:
>> I just installed the lttng package on a fresh Ubuntu 12 machine, and I'm
>> following the tutorial at http://lttng.org/quickstart.
>> The enable-event step fails with this error:
>> # lttng enable-event sched_switch,sys_open -k
>> kernel event sched_switch created in channel channel0
>> Error: Event sys_open: Enable kernel event failed (channel channel0,
>> session mysession)
>> Warning: Some command(s) went wrong
>> What am I doing wrong?
> As of now, you can't enable system calls tracing one by one (sys_open is
> a system call), it's either all of them or none.
> So if you want sched_switch and all the syscalls you have to do :
> lttng enable-event -k sched_switch
> lttng enable-event -k --syscall -a

Well, good to know I guess ;)
I'll update the example on the website.

Thanks for the catch Loris.


Alexandre Montplaisir
École Polytechnique de Montréal

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