Hi, Just to make sure, is your program still running by the time you issue 'lttng list --userspace'? Also, which versions of LTTng are you running and on what kind of system? Are the session daemon and application running under the same user? Please run your application with the LTTNG_UST_DEBUG environment variable set to '1' and provide the output. This will help understand where things go wrong. Thanks, Jérémie -- Jérémie Galarneau EfficiOS Inc. https://www.efficios.com ________________________________ From: lttng-dev on behalf of bule via lttng-dev Sent: November 4, 2022 06:52 To: lttng-dev@lists.lttng.org Subject: [lttng-dev] lttng list --userspace is null hi , I used lttng-ust in my project, it's a dpdk program. I built and run it , and run lttng list --userspace in another terminal ,but the result is null. [image.png] And gdb disassemble result has lttng_ust_tracepoint. [image.png] Then I used lttng-ust in a demo, it works ok. [image.png] so , how to fix it ? Best regards