----- On Mar 26, 2020, at 1:39 PM, lttng-dev <lttng-dev@lists.lttng.org> wrote:
Hello!

Currently, callstack collection in LTTng is only available for kernel-space events with context fields callstack-kernel and callstack-user.

Is it expected that callstack collection for LTTng-UST will be added too? And if it is expected, then how soon?

Hi Valentin,

It is something that would be interesting and useful, but a lot of work would
be needed to have stack-walking this is fast enough and reentrant wrt signal
handlers. Unfortunately, the backtrace(3) functions do not meet those
requirements.

Also, for gathering user-space callstacks from the kernel tracer, it only works if
all user-space is compiled with frame pointers. This is also a limitation that would
require a lot of work to overcome neatly.

None of those features are currently on any roadmap due to lack of customers
showing interest in getting this done.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com