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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">I noticed that the “procname” and “tid” *<b>context</b>* variables can differ from the “comm” and “tid” variables of the sched_stat_-tracepoints (e.g., for sched_stat_runtime).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">For example, see the following two outputs:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">[15:49:33.674072890] (+0.000029771) rng2070 sched_stat_sleep: { cpu_id = 4 }, { pid = 26974, procname = "amcl", tid = 26975 }, { comm = "lttng-sessiond", tid = 798,
delay = 194122524 }<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">[15:49:33.722894563] (+0.000004851) rng2070 sched_stat_sleep: { cpu_id = 0 }, { pid = 0, procname = "swapper/0", tid = 0 }, { comm = "amcl", tid = 27078, delay =
10043658 }<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">In both cases, procname differs from comm. I’ve looked at the kernel source code, and the “comm” variable is taken from task_struct.filename. Barring renames, this
would be the correct one, so I’m assuming that the context is sometimes incorrect.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">Now, for this particular case, I can take the correct variables from the tracepoint, but of course, this makes me worried that the context might also be wrong in
other cases… Do you have any idea what could be going on here?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">LTTng is Version 2.7.x+stable+bzr2948+pack17+201511192116~ubuntu14.04.1 and this is on a 3.19.0-33-generic kernel (btw, that’s not the default kernel for Ubuntu
14.04, but the LTS vivid backport kernel).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE">Mit freundlichen Grüßen / Best regards
<br>
<br>
<b>Ingo Luetkebohle<br>
</b><br>
Application Software (CR/AEA2) <br>
Tel. +49(711)811-12248 | Fax +49(711)811-0 | </span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE"><a href="mailto:Ingo.Luetkebohle@de.bosch.com"><span lang="EN-US" style="color:blue">Ingo.Luetkebohle@de.bosch.com</span></a></span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE">
</span><span lang="EN-US" style="font-size:8.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE"><br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;mso-fareast-language:DE"><br>
<br>
</span><span lang="EN-US"><o:p></o:p></span></p>
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