I took note of http://lwn.net/Articles/492296/ (Mathieu Desnoyers, Julien Desfossez, David Goulet; LTTng 2.0: Tracing for power users and developers - part 2, April 18, 2012) and ran this (using the Ubuntu lttng packages this time; babeltrace is 1.0.0~rc1-0ubuntu1 and lttng is 2.0.1-0ubuntu1 [liblttng-ctl0, lttng-tools] and 2.0.2-0ubuntu1 [liblttng-ust0, lttng-modules-dkms]):
$ sudo -H lttng create calibrate-session Session calibrate-session created. Traces will be written in /root/lttng-traces/calibrate-session-20130213-143220 $ sudo -H lttng enable-event calibrate-event -k --function lttng_calibrate_kretprobe kernel event calibrate-event created in channel channel0 $ sudo -H lttng add-context -k -t perf:LLC-load-misses -t perf:LLC-store-misses -t perf:LLC-prefetch-misses Error: perf:LLC-prefetch-misses: Add kernel context failed kernel context perf:LLC-store-misses added to all channels kernel context perf:LLC-load-misses added to all channels Warning: Some command(s) went wrong $ sudo -H lttng start Tracing started for session calibrate-session $ for a in $(seq 1 10); do \ > sudo -H lttng calibrate -k --function; \ > done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done Kernel calibration done $ sudo -H lttng destroy Session calibrate-session destroyed at /root $ sudo -H babeltrace /root/lttng-traces/calibrate-session-20130213-143220 error syntax error [error] Error creating AST [warning] Unable to open trace metadata for path "/root/lttng-traces/calibrate-session-20130213-143220/kernel". [warning] [Context] Cannot open_trace of the format /root/lttng-traces/calibrate-session-20130213-143220/kernel . [warning] [Context] opening trace "/root/lttng-traces/calibrate-session-20130213-143220/kernel" from /root/lttng-traces/calibrate-session-20130213-143220 for reading. ########## Now, the "Error: perf:LLC-prefetch-misses: Add kernel context failed" is probably because 'dmesg | grep "generic r"' reports just two generic registers, although it seems odd the error would occur on the first context attempt and not the last. My real problem is with the trace thus generated and babeltrace's handling of it. It consists of five files: metadata and channel0_0 through channel0_3. There is no kernel file. I moved the trace to another machine and tried a more up-to-date babeltrace (babeltrace-1.0.3+-217b52c), with little difference: error syntax error [error] Error creating AST [warning] Unable to open trace metadata for path "/home/daniel/lttng-traces/calibrate-session-20130213-143220/kernel". [warning] [Context] Cannot open_trace of format ctf at path /home/daniel/lttng-traces/calibrate-session-20130213-143220/kernel. [warning] [Context] cannot open trace "/home/daniel/lttng-traces/calibrate-session-20130213-143220/kernel" from /home/daniel/lttng-traces/calibrate-session-20130213-143220 for reading. [error] Cannot open any trace for reading. 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
