The calibrate function is just a rough sketch really. It could use some more work, but it's very low priority for now.
If you feel like it, please open a feature request for this against lttng-tools. Thanks, Mathieu * Thibault, Daniel ([email protected]) wrote: > 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 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
