<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body>
Hi,<br>
<br>
Don't forget to cc the mailing list.<br>
<br>
<div class="moz-cite-prefix">On 2016-03-02 02:42 PM, Jeffrey Chen
wrote:<br>
</div>
<blockquote
cite="mid:DM3PR13MB0782CC28E9FE90AA3B35B8E9C7BC0@DM3PR13MB0782.namprd13.prod.outlook.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
</blockquote>
<blockquote
cite="mid:DM3PR13MB0782CC28E9FE90AA3B35B8E9C7BC0@DM3PR13MB0782.namprd13.prod.outlook.com"
type="cite">
<div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">
<p> Even I share our executable, you will not be able to run on
your machine, as it depends on our environment.</p>
</div>
</blockquote>
This is expected, it's also why I asked you if you could provide a
reproducer, a simpler version of your problem that reproduce the
behavior even sporadically.<br>
<br>
<blockquote
cite="mid:DM3PR13MB0782CC28E9FE90AA3B35B8E9C7BC0@DM3PR13MB0782.namprd13.prod.outlook.com"
type="cite">
<div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">
<p>The idea is that, if you spawn some threads, and these
threads keep writing traces through LTTng. Then, exit the main
thread, as in return main() function. LTTng's logic will do
cleanup itself, but my other threads are still writing to
LTTng. This would cause segfault. It would try to reference
address 0x0.<br>
</p>
</div>
</blockquote>
This could be a good start for a simple reproducer. <br>
<br>
Cheers<br>
<blockquote
cite="mid:DM3PR13MB0782CC28E9FE90AA3B35B8E9C7BC0@DM3PR13MB0782.namprd13.prod.outlook.com"
type="cite">
<div id="divtagdefaultwrapper"
style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">
<p>
</p>
<p><br>
</p>
<p><span style="background-color: rgb(255, 255, 0);">#0
0x0000000000000000 in ?? ()</span><br>
#1 0x00007f7e31fdfd78 in
__tracepoint_cb_processor___tracepoint_info (<br>
taskNameArg=0x1cf3c30 "BackgroundTask", dataArg=0x1fd5200
"S")<br>
</p>
...<br>
<br>
<div style="color: rgb(0, 0, 0);">
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
face="Calibri, sans-serif" color="#000000"><b>From:</b>
Jonathan Rajotte Julien
<a class="moz-txt-link-rfc2396E" href="mailto:Jonathan.rajotte-julien@efficios.com"><Jonathan.rajotte-julien@efficios.com></a><br>
<b>Sent:</b> Wednesday, March 2, 2016 11:21 AM<br>
<b>To:</b> Jeffrey Chen<br>
<b>Cc:</b> <a class="moz-txt-link-abbreviated" href="mailto:lttng-dev@lists.lttng.org">lttng-dev@lists.lttng.org</a><br>
<b>Subject:</b> Re: [lttng-dev] Segfault during process
exit</font>
<div> </div>
</div>
<div>Hi,<br>
<br>
Could you provide a reproducer ?<br>
<br>
Could you give us some context ?<br>
<br>
Thanks<br>
<br>
<div class="moz-cite-prefix">On 2016-03-02 02:07 PM, Jeffrey
Chen wrote:<br>
</div>
<blockquote type="cite">
<div id="divtagdefaultwrapper" style="font-size:12pt;
color:#000000; background-color:#FFFFFF;
font-family:Calibri,Arial,Helvetica,sans-serif">
<p>Hi:</p>
<p><br>
</p>
<p>Our system process will spawn several background
threads to do tasks. During the process exit, there is
no guarantee that these background threads are
finished. I have noticed several times that the
execution would segfault during exiting. The
stacktrace is showing that the segfault happened at
the call to write trace, tracepoint(). My guess is
that LTTng cleaned up the tracing connection, and the
background thread was still running. Has anyone
noticed this issue? I thought about trying wait for
all the background threads to complete, but this is
very difficult to do in a complex system, as the
background thread could spawn more threads during the
process. Is there any way to solve this? Thanks.<br>
</p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre>_______________________________________________
lttng-dev mailing list
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:lttng-dev@lists.lttng.org">lttng-dev@lists.lttng.org</a>
<a moz-do-not-send="true" title="Ctrl+Click or tap to follow the link" class="moz-txt-link-freetext" href="http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev">http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Jonathan R. Julien
Efficios</pre>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Jonathan R. Julien
Efficios</pre>
</body>
</html>