... more background. I've always used ltt in the kernel so I don't have much experience with the user side of it and especially multi-threaded, multi-core so I'm probably missing some fundamental concepts that I need to understand.
Regards, Brian On Thu, May 11, 2023 at 11:53 AM Brian Hutchinson <b.hutch...@gmail.com> wrote: > > Hi, > > I posted a while ago (thread - Using lttng 2.11 and UST doesn't appear > to work - getting empty trace files) about this problem I'm having > with getting empty trace logs. > > I've since upgraded to lttng v2.13 and while I can do a simple hello > world program with tracef and get events in the log files, my more > complicated large multi-threaded app I'm trying to debug is still > getting empty log file traces. > > I can list the user space events in my app. > > Next I do: > > lttng enable-event --userspace 'lttng_ust_tracef:*' > > ... to enable the events, start lttng, start my app, .... and I get a > trace directory structure that's empty. > > I feel like I've read every thread in the archives about people having > the same problem. > > I did try using LD_PRELOAD with various libs thinking that was the > problem but so far I'm still getting empty traces. > > So far I've tried: > > LD_PRELOAD=liblttng-ust-libc-wrapper.so.1:liblttng-ust-pthread-wrapper.so.1:liblttng-ust-dl.so.1:liblttng-ust-fork.so.1:liblttng-ust-fd.so.1 > /usr/local/bin/my_app > > I guess one question I have is how do I determine which "helper libs" > I need to preload? > > The application I'm working on is made up of a bunch of smaller static > libs linked together into one big executable and that is linked with > -llttng-ust and -ldl. > > I'm pretty stuck at the moment. Anyone have any wisdom on what I > might be doing wrong or how I can tell why I'm not getting events in > the logs? > > Thanks, > > Brian _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
