On Fri, 9 May 2025 08:45:46 -0700
Namhyung Kim [off-list ref] wrote:

quoted

Is it possible to have many threads writing into the same
ring buffer in that scenario ? Are all event records stamped
with their associated PID ? As long as we have enough information
to know which thread was associated with the timestamp cookie
on both ends (request for callchain and saving the user callchain
on return to userspace), we should be OK.  

Yep, basically perf sets PERF_SAMPLE_TID (and sample_id_all) which makes
every records come with PID/TID.. 

If LTTng is fine with this too, then we should be OK as perf and ftrace
both record TID in the events. I'm assuming that BPF would be OK too.

-- Steve