I dont want to use anything else, I just want to add instrumentation for dynamically loaded tracepoints that does next to nothing if not activated (see [1]). liblttng-ust-ctl is not even ABI compatible between 2.13 and 2.14 (different soname), so that's pretty useless since it already binds to either 2.13 or 2.14 at compile-time.
[1] - https://lists.lttng.org/pipermail/lttng-dev/2021-May/030004.html Norbert Am Mo., 23. Juni 2025 um 16:21 Uhr schrieb Kienan Stewart <kstew...@efficios.com>: > > Hi Norbert, > > If you link to liblttng-ust-ctl, you can use `lttng_ust_ctl_get_version`. > > thanks, > kienan > > > On 6/18/25 11:22 AM, Norbert Lange via lttng-dev wrote: > > Hi, > > > > there are some substantial changes in 2.14.0 that afffect how/if > > tracing is possible. > > For ex. c246521ddcba1d1d28cfa0482aa500b9122e7264 allows doing more work > > upfront > > by calling lttng_ust_init_thread(). > > With 2.13.x the same code will instead do various syscalls or > > allocations during the first tracepoints, violating realtime > > constraints and possible abort the process. > > > > I miss an easy method to inspect the Lttng UST Version for checks or > > workarounds. > > > > There is the lttng_ust_loaded variable that could be abused to carry > > an packed version instead of 1. (Of course that could always cause > > fallout) > > > > Regards, Norbert >
