>   Absolutely: no patching required.

   I decided to find out if the lttng-modules were required at all if one needs 
to do only user-space tracing.

   I installed (on an otherwise lttng-virgin system) just the userspace-rcu, 
lttng-ust, and lttng-tools packages.  The lttng commands fail for the usual 
"can't find /usr/local/lib" reason, so I need to do not:

$ lttng list -u

   but rather

$ LD_PRELOAD=/usr/local/lib/liblttng-ctl.so:/usr/local/lib/liblttng-ust-ctl.so 
lttng list -u

   or

$ LD_LIBRARY_PATH=/usr/local/lib lttng list -u

   However, once I made the lttng-ust/doc/examples/easy-ust sample, I get a 
segmentation fault/core dump after starting the trace.

$ LD_LIBRARY_PATH=/usr/local/lib lttng create usttrace
Session usttrace created.
Traces will be written in /home/daniel/lttng-traces/usttrace-20130418-150106
$ LD_LIBRARY_PATH=/usr/local/lib lttng enable-event -u --all
All UST events are enabled in channel channel0
$ LD_LIBRARY_PATH=/usr/local/lib lttng start
Tracing started for session usttrace
$ LD_LIBRARY_PATH=/usr/local/lib ./sample
Segmentation fault (core dumped)

   Is this supposed to work or are the kernel modules required even when doing 
just pure user-space tracing?  I did get a partial trace on disk (just the 
channel0_0 and metadata files, no events in them).

Daniel U. Thibault
R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D 
Canada - Valcartier (DRDC Valcartier)
Cyber sécurité pour les missions essentielles (CME) / Mission Critical Cyber 
Security (MCCS)
Protection des systèmes et contremesures (PSC) / Systems Protection & 
Countermeasures (SPC)
2459 route de la Bravoure
Québec, QC  G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC : 918V QSDJ <http://www.travelgis.com/map.asp?addr=918V%20QSDJ>
Gouvernement du Canada / Government of Canada
<http://www.valcartier.drdc-rddc.gc.ca/>

_______________________________________________
lttng-dev mailing list
[email protected]
http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

Reply via email to