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7 This file is part of systemd.
9 Copyright 2012 Intel Corporation
12 Auke Kok <auke-jan.h.kok@intel.com>
13 William Giokas <1007380@gmail.com>
15 systemd is free software; you can redistribute it and/or modify it
16 under the terms of the GNU Lesser General Public License as published by
17 the Free Software Foundation; either version 2.1 of the License, or
18 (at your option) any later version.
20 systemd is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 Lesser General Public License for more details.
25 You should have received a copy of the GNU Lesser General Public License
26 along with systemd; If not, see <http://www.gnu.org/licenses/>.
29 <refentry id="systemd-bootchart" conditional='ENABLE_BOOTCHART'>
31 <title>systemd-bootchart</title>
32 <productname>systemd</productname>
36 <contrib>Developer</contrib>
37 <firstname>Auke</firstname>
38 <surname>Kok</surname>
39 <email>auke-jan.h.kok@intel.com</email>
45 <refentrytitle>systemd-bootchart</refentrytitle>
46 <manvolnum>1</manvolnum>
50 <refname>systemd-bootchart</refname>
51 <refpurpose>Boot performance graphing tool</refpurpose>
55 <title>Description</title>
57 <command>systemd-bootchart</command> is a
58 tool, usually run at system startup, that
59 collects the CPU load, disk load, memory
60 usage, as well as per-process information from
61 a running system. Collected results are output
62 as an SVG graph. Normally, systemd-bootchart
63 is invoked by the kernel by passing
64 <option>init=<filename>/usr/lib/systemd/systemd-bootchart</filename></option>
65 on the kernel commandline. systemd-bootchart will then
66 fork the real init off to resume normal system
67 startup, while monitoring and logging startup
68 information in the background.
71 After collecting a certain amount of data
72 (usually 15-30 seconds, default 20 s) the
73 logging stops and a graph is generated from
74 the logged information. This graph contains
75 vital clues as to which resources are being used,
76 in which order, and where possible problems
77 exist in the startup sequence of the system.
78 It is essentially a more detailed version of
79 the <command>systemd-analyze</command>
80 <command>plot</command> function.
83 Of course, bootchart can also be used at any
84 moment in time to collect and graph some data
85 for an amount of time. It is
86 recommended to use the <option>--rel</option>
90 Bootchart does not require root privileges,
91 and will happily run as a normal user.
94 Bootchart graphs are by default written
95 time-stamped in <filename>/run/log</filename>.
101 <title>Invocation</title>
103 <para><command>systemd-bootchart</command> can be invoked in several different ways:</para>
108 <term><emphasis>Kernel invocation</emphasis></term>
109 <listitem><para>The kernel can invoke
110 <command>systemd-bootchart</command>
111 instead of the init process. In turn,
112 <command>systemd-bootchart</command>
113 will invoke <command>/sbin/init</command>.
118 <term><emphasis>Started as a standalone program</emphasis></term>
119 <listitem><para>One can execute
120 <command>systemd-bootchart</command>
121 as normal application from the
122 commandline. In this mode it is highly
123 recommended to pass the
124 <option>-r</option> flag in order to
125 not graph the time elapsed since boot
126 and before systemd-bootchart was
127 started, as it may result in extremely
128 large graphs. </para></listitem>
134 <title>Options</title>
136 <para>These options can also be set in the
137 <filename>/etc/systemd/bootchart.conf</filename>
139 <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
145 <term><option>-n</option></term>
146 <term><option>--sample <replaceable>N</replaceable></option></term>
147 <listitem><para>Specify the number of
148 samples, <replaceable>N</replaceable>,
149 to record. Samples will be recorded at
150 intervals defined with <option>--freq</option>.
155 <term><option>-f</option></term>
156 <term><option>--freq <replaceable>f</replaceable></option></term>
157 <listitem><para>Specify the sample log
158 frequency, a positive real <replaceable>f</replaceable>, in Hz.
159 Most systems can cope with values up to 25-50 without
160 creating too much overhead.</para></listitem>
164 <term><option>-r</option></term>
165 <term><option>--rel</option></term>
166 <listitem><para>Use relative times instead of absolute
167 times. This is useful for using bootchart at post-boot
168 time to profile an already booted system. Without this
169 option the graph would become extremely large. If set, the
170 horizontal axis starts at the first recorded sample
171 instead of time 0.0.</para></listitem>
175 <term><option>-F</option></term>
176 <term><option>--no-filter</option></term>
177 <listitem><para>Disable filtering of tasks that
178 did not contribute significantly to the boot. Processes
179 that are too short-lived (only seen in one sample) or
180 that do not consume any significant CPU time (less than
181 0.001 s) will not be displayed in the output graph.
186 <term><option>-o</option></term>
187 <term><option>--output <replaceable>path</replaceable></option></term>
188 <listitem><para>Specify the output folder for the
189 graphs. By default, bootchart writes the graphs to
190 <filename>/run/log</filename>.</para></listitem>
194 <term><option>-i</option></term>
195 <term><option>--init <replaceable>path</replaceable></option></term>
196 <listitem><para>Use this init binary. Defaults to
197 <command>/sbin/init</command>.
202 <term><option>-p</option></term>
203 <term><option>--pss</option></term>
204 <listitem><para>Enable logging and graphing
205 of processes' PSS (Proportional Set Size)
206 memory consumption. See <filename>filesystems/proc.txt</filename>
207 in the kernel documentation for an
208 explanation of this field.
213 <term><option>-e</option></term>
214 <term><option>--entropy</option></term>
215 <listitem><para>Enable logging and graphing
216 of the kernel random entropy pool size.</para></listitem>
220 <term><option>-x</option></term>
221 <term><option>--scale-x <replaceable>N</replaceable></option></term>
222 <listitem><para>Horizontal scaling factor for all variable
223 graph components.</para></listitem>
227 <term><option>-y</option></term>
228 <term><option>--scale-y <replaceable>N</replaceable></option></term>
229 <listitem><para>Vertical scaling factor for all variable
230 graph components.</para></listitem>
239 <title>Output</title>
241 <para><command>systemd-bootchart</command> generates SVG graphs. In order to render those
242 on a graphical display any SVG capable viewer can be used. It should be
243 noted that the SVG render engines in most browsers (including Chrome
244 and Firefox) are many times faster than dedicated graphical applications
245 like Gimp and Inkscape. Just point your browser at <ulink url="file:///run/log/" />!
250 <title>History</title>
252 <para>This version of bootchart was implemented from
253 scratch, but is inspired by former bootchart
258 <term><emphasis>Original bash</emphasis></term>
259 <listitem><para>The original bash/shell code implemented
260 bootchart. This version created a compressed tarball for
261 processing with external applications. This version did
262 not graph anything, only generated data.</para></listitem>
266 <term><emphasis>Ubuntu C Implementation</emphasis></term>
267 <listitem><para>This version replaced the shell version with
268 a fast and efficient data logger, but also did not graph
269 the data.</para></listitem>
273 <term><emphasis>Java bootchart</emphasis></term>
274 <listitem><para>This was the original graphing application
275 for charting the data, written in java.</para></listitem>
279 <term><emphasis>pybootchartgui.py</emphasis></term>
280 <listitem><para>pybootchart created a graph from the data
281 collected by either the bash or C version.</para></listitem>
285 <para>The version of bootchart you are using now combines both the data
286 collection and the charting into a single application, making it more
287 efficient and simpler. There are no longer any timing issues with the data
288 collector and the grapher, as the graphing cannot be run until the data
289 has been collected. Also, the data kept in memory is reduced to the absolute
290 minimum needed.</para>
295 <title>See Also</title>
297 <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
303 <para>systemd-bootchart does not get the model information for the hard drive
304 unless the root device is specified with <code>root=/dev/sdxY</code>. Using
305 UUIDs or PARTUUIDs will boot fine, but the hard drive model will not be
306 added to the chart.</para>
307 <para>For bugs, please contact the author and current maintainer:</para>
309 <member>Auke Kok <email>auke-jan.h.kok@intel.com</email></member>