Re: How to show method entry/exit in Trace Compass?

Matthew Khouzam via lttng-dev <[email protected]> Fri, 1 May 2026 19:31:43 +0000
Newsgroups org.lttng.lists.lttng-dev
Message-ID <DS4PPFB691D9211860531ADD6E93FC33BA79E322@DS4PPFB691D9211.namprd15.prod.outlook.com>
--_000_DS4PPFB691D9211860531ADD6E93FC33BA79E322DS4PPFB691D9211_
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

Hi David,

I would love to look into the "lost event". Can you share the trace? maybe =
it's an easy win.
________________________________
From: lttng-dev <[email protected]> on behalf of David Aldr=
ich via lttng-dev <[email protected]>
Sent: Thursday, April 30, 2026 7:01 PM
To: [email protected] <[email protected]>
Subject: How to show method entry/exit in Trace Compass?

Hi

I'm using LTTng 2.13.11 on Ubuntu 24.04 with Trace Compass 11.3.0 on Window=
s, to analyse a C++ app.

I have used LTTng and Trace Compass a little to instrument our user space a=
pp using  lttng_ust_tracef(). I now want to show actual method entry/exit p=
oints in a Gantt type view.

With help from AI I instrumented entry/exit for one method. Babeltrace show=
s that the trace files contain those points:

<time> sr1  myapp:method_entry: { cpu_id =3D 4 }, { class =3D "ThreadPool",=
 method =3D "mainLoop" }
<time> sr1 myapp:method_exit: { cpu_id =3D 6 }, { class =3D "ThreadPool", m=
ethod =3D "mainLoop" }

But when I import the trace into Trace Compass I see the events but the tra=
ce shows only the app name, not the method name.

What am I missing? Is there a user guide article that would help me?

Best regards
David

--_000_DS4PPFB691D9211860531ADD6E93FC33BA79E322DS4PPFB691D9211_
Content-Type: text/html; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dus-ascii"=
>
<style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo=
ttom:0;} </style>
</head>
<body dir=3D"ltr">
<div class=3D"elementToProof" style=3D"font-family: Aptos, Aptos_EmbeddedFo=
nt, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; c=
olor: rgb(0, 0, 0);">
Hi David,</div>
<div class=3D"elementToProof" style=3D"font-family: Aptos, Aptos_EmbeddedFo=
nt, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; c=
olor: rgb(0, 0, 0);">
<br>
</div>
<div class=3D"elementToProof" style=3D"font-family: Aptos, Aptos_EmbeddedFo=
nt, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; c=
olor: rgb(0, 0, 0);">
I would love to look into the &quot;lost event&quot;. Can you share the tra=
ce? maybe it's an easy win.</div>
<div id=3D"appendonsend"></div>
<hr style=3D"display:inline-block;width:98%" tabindex=3D"-1">
<div id=3D"divRplyFwdMsg" dir=3D"ltr"><font face=3D"Calibri, sans-serif" st=
yle=3D"font-size:11pt" color=3D"#000000"><b>From:</b> lttng-dev &lt;lttng-d=
[email protected]&gt; on behalf of David Aldrich via lttng-dev &lt=
;[email protected]&gt;<br>
<b>Sent:</b> Thursday, April 30, 2026 7:01 PM<br>
<b>To:</b> [email protected] &lt;[email protected]&gt;<br>
<b>Subject:</b> How to show method entry/exit in Trace Compass?</font>
<div>&nbsp;</div>
</div>
<div>
<div dir=3D"ltr">Hi<br>
<br>
I'm using LTTng 2.13.11 on&nbsp;Ubuntu 24.04 with Trace Compass 11.3.0 on&n=
bsp;Windows,&nbsp;to analyse a C++ app.
<div><br>
I have used LTTng and Trace Compass a little to instrument our user space a=
pp using&nbsp;&nbsp;lttng_ust_tracef(). I now want to show actual method en=
try/exit points in a Gantt type view.</div>
<div><br>
</div>
<div>With help from AI I instrumented entry/exit for one method. Babeltrace=
 shows that the trace files contain those points:<br>
<br>
&lt;time&gt; sr1&nbsp; myapp:method_entry: { cpu_id =3D 4 }, { class =3D &q=
uot;ThreadPool&quot;, method =3D &quot;mainLoop&quot; }</div>
<div>&lt;time&gt; sr1 myapp:method_exit: { cpu_id =3D 6 }, { class =3D &quo=
t;ThreadPool&quot;, method =3D &quot;mainLoop&quot; }</div>
<div><br>
</div>
<div>But when I import the trace into Trace Compass I see the events but th=
e trace shows only the app name, not the method name.<br>
<br>
What am I missing? Is there a user guide article that would help me?<br>
<br>
Best regards</div>
<div>David</div>
</div>
</div>
</body>
</html>

--_000_DS4PPFB691D9211860531ADD6E93FC33BA79E322DS4PPFB691D9211_--