<?xml version='1.0'?> <!--*-nxml-*-->

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="systemd-bootchart" conditional='ENABLE_BOOTCHART'

xmlns:xi="http://www.w3.org/2001/XInclude">

<refentryinfo>

<title>systemd-bootchart</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Auke</firstname>

<surname>Kok</surname>

<email>auke-jan.h.kok@intel.com</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>systemd-bootchart</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>systemd-bootchart</refname>

<refpurpose>Boot performance graphing tool</refpurpose>

</refnamediv>

<refsect1>

<title>Description</title>

<para>

<command>systemd-bootchart</command> is a tool, usually run at

system startup, that collects the CPU load, disk load, memory

usage, as well as per-process information from a running system.

Collected results are output as an SVG graph. Normally,

systemd-bootchart is invoked by the kernel by passing

<option>init=<filename>/usr/lib/systemd/systemd-bootchart</filename></option>

on the kernel command line. systemd-bootchart will then fork the

real init off to resume normal system startup, while monitoring

and logging startup information in the background.

</para>

<para>

After collecting a certain amount of data (usually 15–30

seconds, default 20 s) the logging stops and a graph is

generated from the logged information. This graph contains vital

clues as to which resources are being used, in which order, and

where possible problems exist in the startup sequence of the

system. It is essentially a more detailed version of the

<command>systemd-analyze plot</command> function.

</para>

<para>

Of course, bootchart can also be used at any moment in time to

collect and graph some data for an amount of time. It is

recommended to use the <option>--rel</option> switch in this

case.

</para>

<para>

Bootchart does not require root privileges, and will happily run

as a normal user.

</para>

<para>

Bootchart graphs are by default written time-stamped in

<filename>/run/log</filename> and saved to the journal with

<varname>MESSAGE_ID=9f26aa562cf440c2b16c773d0479b518</varname>.

Journal field <varname>BOOTCHART=</varname> contains the

bootchart in SVG format.

</para>

</refsect1>

<refsect1>

<title>Invocation</title>

<para><command>systemd-bootchart</command> can be invoked in several different ways:</para>

<variablelist>

<varlistentry>

<term><emphasis>Kernel invocation</emphasis></term>

<listitem><para>The kernel can invoke

<command>systemd-bootchart</command> instead of the init

process. In turn, <command>systemd-bootchart</command> will

invoke <command>/usr/lib/systemd/systemd</command>.

</para></listitem>

</varlistentry>

<varlistentry>

<term><emphasis>Started as a standalone program</emphasis></term>

<listitem><para>One can execute

<command>systemd-bootchart</command> as normal application

from the command line. In this mode, it is highly recommended

to pass the <option>-r</option> flag in order to not graph the

time elapsed since boot and before systemd-bootchart was

started, as it may result in extremely large graphs. The time

elapsed since boot might also include any time that the system

was suspended.</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Options</title>

<para>These options can also be set in the

<filename>/etc/systemd/bootchart.conf</filename> file. See

<citerefentry project='man-pages'><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.

</para>

<variablelist>

<xi:include href="standard-options.xml" xpointer="help" />

<varlistentry>

<term><option>-n</option></term>

<term><option>--sample <replaceable>N</replaceable></option></term>

<listitem><para>Specify the number of samples,

<replaceable>N</replaceable>, to record. Samples will be

recorded at intervals defined with <option>--freq</option>.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-f</option></term>

<term><option>--freq <replaceable>f</replaceable></option></term>

<listitem><para>Specify the sample log frequency, a positive

real <replaceable>f</replaceable>, in Hz. Most systems can

cope with values up to 25–50 without creating too much

overhead.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-r</option></term>

<term><option>--rel</option></term>

<listitem><para>Use relative times instead of absolute times.

This is useful for using bootchart at post-boot time to

profile an already booted system. Without this option the

graph would become extremely large. If set, the horizontal

axis starts at the first recorded sample instead of time

0.0.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-F</option></term>

<term><option>--no-filter</option></term>

<listitem><para>Disable filtering of tasks that did not

contribute significantly to the boot. Processes that are too

short-lived (only seen in one sample) or that do not consume

any significant CPU time (less than 0.001 s) will not be

displayed in the output graph. </para></listitem>

</varlistentry>

<varlistentry>

<term><option>-C</option></term>

<term><option>--cmdline</option></term>

<listitem><para>Display the full command line with arguments

of processes, instead of only the process name.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-g</option></term>

<term><option>--control-group</option></term>

<listitem><para>Display process control group

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-o</option></term>

<term><option>--output <replaceable>path</replaceable></option></term>

<listitem><para>Specify the output directory for the graphs.

By default, bootchart writes the graphs to

<filename>/run/log</filename>.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-i</option></term>

<term><option>--init <replaceable>path</replaceable></option></term>

<listitem><para>Use this init binary. Defaults to

<command>/usr/lib/systemd/systemd</command>.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-p</option></term>

<term><option>--pss</option></term>

<listitem><para>Enable logging and graphing of processes' PSS

(Proportional Set Size) memory consumption. See

<filename>filesystems/proc.txt</filename> in the kernel

documentation for an explanation of this field.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-e</option></term>

<term><option>--entropy</option></term>

<listitem><para>Enable logging and graphing of the kernel

random entropy pool size.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-x</option></term>

<term><option>--scale-x <replaceable>N</replaceable></option></term>

<listitem><para>Horizontal scaling factor for all variable

graph components.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-y</option></term>

<term><option>--scale-y <replaceable>N</replaceable></option></term>

<listitem><para>Vertical scaling factor for all variable graph

components.</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Output</title>

<para><command>systemd-bootchart</command> generates SVG graphs.

In order to render those on a graphical display any SVG capable

viewer can be used. It should be noted that the SVG render engines

in most browsers (including Chrome and Firefox) are many times

faster than dedicated graphical applications like Gimp and

Inkscape. Just point your browser at

<ulink url="file:///run/log/" />!

</para>

</refsect1>

<refsect1>

<title>History</title>

<para>This version of bootchart was implemented from scratch, but

is inspired by former bootchart incantations:</para>

<variablelist>

<varlistentry>

<term><emphasis>Original bash</emphasis></term>

<listitem><para>The original bash/shell code implemented

bootchart. This version created a compressed tarball for

processing with external applications. This version did not

graph anything, only generated data.</para></listitem>

</varlistentry>

<varlistentry>

<term><emphasis>Ubuntu C Implementation</emphasis></term>

<listitem><para>This version replaced the shell version with a

fast and efficient data logger, but also did not graph the

data.</para></listitem>

</varlistentry>

<varlistentry>

<term><emphasis>Java bootchart</emphasis></term>

<listitem><para>This was the original graphing application for

charting the data, written in java.</para></listitem>

</varlistentry>

<varlistentry>

<term><emphasis>pybootchartgui.py</emphasis></term>

<listitem><para>pybootchart created a graph from the data

collected by either the bash or C version.</para></listitem>

</varlistentry>

</variablelist>

<para>The version of bootchart you are using now combines both the

data collection and the charting into a single application, making

it more efficient and simpler. There are no longer any timing

issues with the data collector and the grapher, as the graphing

cannot be run until the data has been collected. Also, the data

kept in memory is reduced to the absolute minimum needed.</para>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry project='man-pages'><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>

</para>

</refsect1>

<refsect1>

<title>Bugs</title>

<para>systemd-bootchart does not get the model information for the

hard drive unless the root device is specified with

<code>root=/dev/sdxY</code>. Using UUIDs or PARTUUIDs will boot

fine, but the hard drive model will not be added to the

chart.</para>

<para>For bugs, please contact the author and current maintainer:</para>

<simplelist>

<member>Auke Kok <email>auke-jan.h.kok@intel.com</email></member>

</simplelist>

</refsect1>

</refentry>