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<!DOCTYPE chapter SYSTEM "chapter.dtd">
<chapter>
<header>
<copyright>
<year>2016</year><year>2016</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
Licensed under the Apache License, Version 2.0 (the "License");
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<title>LTTng and Erlang/OTP</title>
<prepared></prepared>
<responsible></responsible>
<docno></docno>
<approved></approved>
<checked></checked>
<date>2016-04-27</date>
<rev></rev>
<file>LTTng.xml</file>
</header>
<section>
<title>Introduction</title>
<p>The Linux Trace Toolkit: next generation is an open source system software package
for correlated tracing of the Linux kernel, user applications and libraries. </p>
<p>For more information, please visit <url href="http://lttng.org">http://lttng.org</url></p>
</section>
<section>
<title>Building Erlang/OTP with LTTng support</title>
<p>
Configure and build Erlang with LTTng support:
</p>
<p>For LTTng to work properly with Erlang/OTP you need
the following packages installed:</p>
<list type="bulleted">
<item><p>LTTng-tools: a command line interface to control tracing sessions.</p></item>
<item><p>LTTng-UST: user space tracing library.</p></item>
</list>
<p>On Ubuntu this can be installed via <c>aptitude</c>:</p>
<code type="none">$ sudo aptitude install lttng-tools liblttng-ust-dev</code>
<p>See <url href="http://lttng.org/docs/#doc-installing-lttng">Installing LTTng</url>
for more information on how to install LTTng on your system.</p>
<p>After LTTng is properly installed on the system Erlang/OTP can be built with LTTng support.</p>
<code type="none">$ ./configure --with-dynamic-trace=lttng
$ make </code>
</section>
<section>
<title>Dyntrace Tracepoints</title>
<p>All tracepoints are in the domain of <c>com_ericsson_dyntrace</c></p>
<p>All Erlang types are the string equivalent in LTTng.</p>
<p><em>process_spawn</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>parent : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>entry : string</c> :: Code Location. Ex. <c>"lists:sort/1"</c></item>
</list>
<p>Example:</p>
<p><code type="none">process_spawn: { cpu_id = 3 }, { pid = "<0.131.0>", parent = "<0.130.0>", entry = "erlang:apply/2" }</code></p>
<p><em>process_link</em></p>
<list type="bulleted">
<item><c>to : string</c> :: Process ID or Port ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>from : string</c> :: Process ID or Port ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>type : string</c> :: <c>"link" | "unlink"</c></item>
</list>
<p>Example:</p>
<p><code type="none">process_link: { cpu_id = 3 }, { from = "<0.130.0>", to = "<0.131.0>", type = "link" }</code></p>
<p><em>process_exit</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>reason : string</c> :: Exit reason. Ex. <c>"normal"</c></item>
</list>
<p>Example:</p>
<p><code type="none">process_exit: { cpu_id = 3 }, { pid = "<0.130.0>", reason = "normal" }</code></p>
<p><em>process_register</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>name : string</c> :: Registered name. Ex. <c>"error_logger"</c></item>
<item><c>type : string</c> :: <c>"register" | "unregister"</c></item>
</list>
<p>Example:</p>
<p><code type="none">process_register: { cpu_id = 0 }, { pid = "<0.128.0>", name = "dyntrace_lttng_SUITE" type = "register" }</code></p>
<p><em>process_scheduled</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>entry : string</c> :: Code Location. Ex. <c>"lists:sort/1"</c></item>
<item><c>type : string</c> :: <c>"in" | "out" | "in_exiting" | "out_exiting" | "out_exited"</c></item>
</list>
<p>Example:</p>
<p><code type="none">process_scheduled: { cpu_id = 0 }, { pid = "<0.136.0>", entry = "erlang:apply/2", type = "in" }</code></p>
<p><em>port_open</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>driver : string</c> :: Driver name. Ex. <c>"efile"</c></item>
<item><c>port : string</c> :: Port ID. Ex. <c>"#Port<0.1031>"</c></item>
</list>
<p>Example:</p>
<p><code type="none">port_open: { cpu_id = 5 }, { pid = "<0.131.0>", driver = "'/bin/sh -s unix:cmd'", port = "#Port<0.1887>" }</code></p>
<p><em>port_exit</em></p>
<list type="bulleted">
<item><c>port : string</c> :: Port ID. Ex. <c>"#Port<0.1031>"</c></item>
<item><c>reason : string</c> :: Exit reason. Ex. <c>"normal"</c></item>
</list>
<p>Example:</p>
<p><code type="none">port_exit: { cpu_id = 5 }, { port = "#Port<0.1887>", reason = "normal" }</code></p>
<p><em>port_link</em></p>
<list type="bulleted">
<item><c>to : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>from : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>type : string</c> :: <c>"link" | "unlink"</c></item>
</list>
<p>Example:</p>
<p><code type="none">port_link: { cpu_id = 5 }, { from = "#Port<0.1887>", to = "<0.131.0>", type = "unlink" }</code></p>
<p><em>port_scheduled</em></p>
<list type="bulleted">
<item><c>port : string</c> :: Port ID. Ex. <c>"#Port<0.1031>"</c></item>
<item><c>entry : string</c> :: Callback. Ex. <c>"open"</c></item>
<item><c>type : string</c> :: <c>"in" | "out" | "in_exiting" | "out_exiting" | "out_exited"</c></item>
</list>
<p>Example:</p>
<p><code type="none">port_scheduled: { cpu_id = 5 }, { pid = "#Port<0.1905>", entry = "close", type = "out" }</code></p>
<p><em>function_call</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>entry : string</c> :: Code Location. Ex. <c>"lists:sort/1"</c></item>
<item><c>depth : integer</c> :: Stack depth. Ex. <c>0</c></item>
</list>
<p>Example:</p>
<p><code type="none">function_call: { cpu_id = 5 }, { pid = "<0.145.0>", entry = "dyntrace_lttng_SUITE:'-t_call/1-fun-1-'/0", depth = 0 }</code></p>
<p><em>function_return</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>entry : string</c> :: Code Location. Ex. <c>"lists:sort/1"</c></item>
<item><c>depth : integer</c> :: Stack depth. Ex. <c>0</c></item>
</list>
<p>Example:</p>
<p><code type="none">function_return: { cpu_id = 5 }, { pid = "<0.145.0>", entry = "dyntrace_lttng_SUITE:waiter/0", depth = 0 }</code></p>
<p><em>function_exception</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>entry : string</c> :: Code Location. Ex. <c>"lists:sort/1"</c></item>
<item><c>class : string</c> :: Error reason. Ex. <c>"error"</c></item>
</list>
<p>Example:</p>
<p><code type="none">function_exception: { cpu_id = 5 }, { pid = "<0.144.0>", entry = "t:call_exc/1", class = "error" }</code></p>
<p><em>message_send</em></p>
<list type="bulleted">
<item><c>from : string</c> :: Process ID or Port ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>to : string</c> :: Process ID or Port ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>message : string</c> :: Message sent. Ex. <c>"{<0.162.0>,ok}"</c></item>
</list>
<p>Example:</p>
<p><code type="none">message_send: { cpu_id = 3 }, { from = "#Port<0.1938>", to = "<0.160.0>", message = "{#Port<0.1938>,eof}" }</code></p>
<p><em>message_receive</em></p>
<list type="bulleted">
<item><c>to : string</c> :: Process ID or Port ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>message : string</c> :: Message received. Ex. <c>"{<0.162.0>,ok}"</c></item>
</list>
<p>Example:</p>
<p><code type="none">message_receive: { cpu_id = 7 }, { to = "<0.167.0>", message = "{<0.165.0>,ok}" }</code></p>
<p><em>gc_minor_start</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>need : integer</c> :: Heap need. Ex. <c>2</c></item>
<item><c>heap : integer</c> :: Young heap word size. Ex. <c>233</c></item>
<item><c>old_heap : integer</c> :: Old heap word size. Ex. <c>233</c></item>
</list>
<p>Example:</p>
<p><code type="none">gc_minor_start: { cpu_id = 0 }, { pid = "<0.172.0>", need = 0, heap = 610, old_heap = 0 }</code></p>
<p><em>gc_minor_end</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>reclaimed : integer</c> :: Heap reclaimed. Ex. <c>2</c></item>
<item><c>heap : integer</c> :: Young heap word size. Ex. <c>233</c></item>
<item><c>old_heap : integer</c> :: Old heap word size. Ex. <c>233</c></item>
</list>
<p>Example:</p>
<p><code type="none">gc_minor_end: { cpu_id = 0 }, { pid = "<0.172.0>", reclaimed = 120, heap = 1598, old_heap = 1598 }</code></p>
<p><em>gc_major_start</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>need : integer</c> :: Heap need. Ex. <c>2</c></item>
<item><c>heap : integer</c> :: Young heap word size. Ex. <c>233</c></item>
<item><c>old_heap : integer</c> :: Old heap word size. Ex. <c>233</c></item>
</list>
<p>Example:</p>
<p><code type="none">gc_major_start: { cpu_id = 0 }, { pid = "<0.172.0>", need = 8, heap = 2586, old_heap = 1598 }</code></p>
<p><em>gc_major_end</em></p>
<list type="bulleted">
<item><c>pid : string</c> :: Process ID. Ex. <c>"<0.131.0>"</c></item>
<item><c>reclaimed : integer</c> :: Heap reclaimed. Ex. <c>2</c></item>
<item><c>heap : integer</c> :: Young heap word size. Ex. <c>233</c></item>
<item><c>old_heap : integer</c> :: Old heap word size. Ex. <c>233</c></item>
</list>
<p>Example:</p>
<p><code type="none">gc_major_end: { cpu_id = 0 }, { pid = "<0.172.0>", reclaimed = 240, heap = 4185, old_heap = 0 }</code></p>
</section>
<section>
<title>Examples</title>
</section>
</chapter>
