<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Hi,</div><div><br></div><div>As i am new to lttng usage, I have followed the instructions from <https://launchpad.net/~lttng/+archive/ppa> in order to install the lttng tool set in my ubuntu 11.10.</div><div>After successful installation, i followed the getting started link on lttng.org <http://lttng.org/quickstart> in "root mode".</div><div><br></div><div>1. when i am executing the first command - <br></div><div><span class="tab"> </span># lttng list -k</div><div><br></div><div><span class="tab"> </span>i am getting the following error</div><div><span class="tab"> </span>" Error: Unable to list kernel events"</div><div><br></div><div>2. # lttng create mysession<br><span class="tab"> </span>Session mysession
created.</div><div><br></div><div>3. # lttng enable-event sched_switch,sched_process_fork -k<br><span class="tab"> </span>Error: Event sched_switch: Kernel tracer not available (channel channel0, session mysession)<br><span class="tab"> </span>Error: Event sched_process_fork: Kernel tracer not available (channel channel0, session mysession)<br><span class="tab"> </span>Warning: Some command(s) went wrong <br></div><div><br></div><div>4. # lttng start<br><span class="tab"> </span>Tracing started for session mysession</div><div><br></div><div>5. # lttng stop<br><span class="tab"> </span>Tracing stopped for session mysession</div><div><br></div><div>6.<span class="tab"> # lttng destroy<br></span><span class="tab"> </span><span class="tab">Session mysession destroyed at /root</span></div><div><br><span class="tab"></span></div><div><span
class="tab">------------</span></div><div><br></div><div>I have checked that lttng-sessiond is running by below command <br></div><div><br></div><div># ps -ef|grep lttn<br>root 535 1 0 Jun14 ? 00:00:00 lttng-sessiond<br>somanath 5359 1 0 Jun14 pts/1 00:00:00 lttng-sessiond --sig-parent --quiet<br>root 19514 19495 0 12:44 pts/2 00:00:00 grep --color=auto lttn<br><span class="tab"></span></div><div>--------------</div><div><br></div><div>Could anyone please help me to understand or clarify why kernel tracer is not available when above point (3) / (1) is executed or whether i need to do anything more , please let me know so that i can start using lttng in ubuntu 11.10 successfully.<br></div><div><br></div><div>I have googled about this problem, I got
to know about this similar problem from one link - http://www.mail-archive.com/lttng-dev@lists.lttng.org/msg00763.html</div><div>However i executed all this commands under root and explicit lttng-seesiond start, But still the problem is persistant.<br></div><div><br></div><div><br></div><div>Any help will be appreciated.</div><div><br></div><div><br></div><div>Thanks & Regards,<br>Somanath<br> </div><div><br></div><div><br></div><div><br></div><div><br><span class="tab"></span></div><div><span class="tab"><br></span></div></div></body></html>