Hi Julien, On Wed, Mar 24, 2021 at 11:29:04AM +0000, MONTET Julien via lttng-dev wrote: > Hello the LTTng team ! > > I would like, at first, to thank you for your projet and your impressive work > ! > > For the past few days I have been trying to learn how to use lttng (v2.12). > > I followed the installation on your website for an Ubuntu 20.04. > [cid:c663399f-0584-43d3-90c5-3aa277ee7020]
Good. So just to validate you used the stable 2.12 PPA as described in this section [1] ?. [1] https://lttng.org/docs/v2.12/#doc-ubuntu-ppa > > The steps to get the trace of a Linux kernel and the babel trace are great ! > > However, I am stuck for the 'Trace a user application' : > https://lttng.org/docs/v2.12/#doc-tracing-your-own-user-application > Compilation steps are ok, it launches without error but lttng list > --userspace gives me nothing. When you perform the `lttng list --userspace` command is your user application running? If not, `lttng list --userspace` can only list running application. If your application is running, we will need to go a bit further and have some debug info. You can at least check if lttng-ust, on the application side, can successfully communicate with the lttng-sessiond process. For this, you will have to use LTTNG_UST_DEBUG. Here's how to us it: 1) Make sure a lttng-sessiond is present, 2) Start your application like so: LTTNG_UST_DEBUG=1 your_application, 3) Debug messages from lttng-ust should appear on the stderr. Please use a paste service [2] to share this information with us. [2] https://paste.ubuntu.com/ Au plaisir! -- Jonathan Rajotte-Julien EfficiOS _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
