chiark / gitweb /
udev: rename kernel command line option to net.ifnames=
[elogind.git] / man / systemd-bootchart.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5
6 <!--
7   This file is part of systemd.
8
9   Copyright 2012 Intel Corporation
10
11   Authors:
12     Auke Kok <auke-jan.h.kok@intel.com>
13     William Giokas <1007380@gmail.com>
14
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.
19
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.
24
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/>.
27 -->
28
29 <refentry id="systemd-bootchart" conditional='ENABLE_BOOTCHART'>
30         <refentryinfo>
31                 <title>systemd-bootchart</title>
32                 <productname>systemd</productname>
33
34                 <authorgroup>
35                         <author>
36                                 <contrib>Developer</contrib>
37                                 <firstname>Auke</firstname>
38                                 <surname>Kok</surname>
39                                 <email>auke-jan.h.kok@intel.com</email>
40                         </author>
41                 </authorgroup>
42         </refentryinfo>
43
44         <refmeta>
45                 <refentrytitle>systemd-bootchart</refentrytitle>
46                 <manvolnum>1</manvolnum>
47         </refmeta>
48
49         <refnamediv>
50                 <refname>systemd-bootchart</refname>
51                 <refpurpose>Boot performance graphing tool</refpurpose>
52         </refnamediv>
53
54         <refsect1>
55                 <title>Description</title>
56                 <para>
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.
69                 </para>
70                 <para>
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.
81                 </para>
82                 <para>
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>
87                         switch in this case.
88                 </para>
89                 <para>
90                         Bootchart does not require root privileges,
91                         and will happily run as a normal user.
92                 </para>
93                 <para>
94                         Bootchart graphs are by default written
95                         time-stamped in <filename>/run/log</filename>.
96                 </para>
97
98         </refsect1>
99
100         <refsect1>
101                 <title>Invocation</title>
102
103                 <para><command>systemd-bootchart</command> can be invoked in several different ways:</para>
104
105                 <variablelist>
106
107                         <varlistentry>
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>.
114                                 </para></listitem>
115                         </varlistentry>
116
117                         <varlistentry>
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>
129                         </varlistentry>
130                 </variablelist>
131         </refsect1>
132
133         <refsect1>
134                 <title>Options</title>
135
136                 <para>These options can also be set in the
137                 <filename>/etc/systemd/bootchart.conf</filename>
138                 file. See
139                 <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
140                 </para>
141
142                 <variablelist>
143
144                         <varlistentry>
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>.
151                                 </para></listitem>
152                         </varlistentry>
153
154                         <varlistentry>
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>
161                         </varlistentry>
162
163                         <varlistentry>
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>
172                         </varlistentry>
173
174                         <varlistentry>
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.
182                                 </para></listitem>
183                         </varlistentry>
184
185                         <varlistentry>
186                                 <term><option>-C</option></term>
187                                 <term><option>--cmdline</option></term>
188                                 <listitem><para>Display the full command line with arguments of processes,
189                                 instead of only the process name.
190                                 </para></listitem>
191                         </varlistentry>
192
193                         <varlistentry>
194                                 <term><option>-o</option></term>
195                                 <term><option>--output <replaceable>path</replaceable></option></term>
196                                 <listitem><para>Specify the output folder for the
197                                 graphs. By default, bootchart writes the graphs to
198                                 <filename>/run/log</filename>.</para></listitem>
199                         </varlistentry>
200
201                         <varlistentry>
202                                 <term><option>-i</option></term>
203                                 <term><option>--init <replaceable>path</replaceable></option></term>
204                                 <listitem><para>Use this init binary. Defaults to
205                                 <command>/sbin/init</command>.
206                                 </para></listitem>
207                         </varlistentry>
208
209                         <varlistentry>
210                                 <term><option>-p</option></term>
211                                 <term><option>--pss</option></term>
212                                 <listitem><para>Enable logging and graphing
213                                 of processes' PSS (Proportional Set Size)
214                                 memory consumption. See <filename>filesystems/proc.txt</filename>
215                                 in the kernel documentation for an
216                                 explanation of this field.
217                                 </para></listitem>
218                         </varlistentry>
219
220                         <varlistentry>
221                                 <term><option>-e</option></term>
222                                 <term><option>--entropy</option></term>
223                                 <listitem><para>Enable logging and graphing
224                                 of the kernel random entropy pool size.</para></listitem>
225                         </varlistentry>
226
227                         <varlistentry>
228                                 <term><option>-x</option></term>
229                                 <term><option>--scale-x <replaceable>N</replaceable></option></term>
230                                 <listitem><para>Horizontal scaling factor for all variable
231                                 graph components.</para></listitem>
232                         </varlistentry>
233
234                         <varlistentry>
235                                 <term><option>-y</option></term>
236                                 <term><option>--scale-y <replaceable>N</replaceable></option></term>
237                                 <listitem><para>Vertical scaling factor for all variable
238                                 graph components.</para></listitem>
239                         </varlistentry>
240
241                 </variablelist>
242
243
244         </refsect1>
245
246         <refsect1>
247                 <title>Output</title>
248
249                 <para><command>systemd-bootchart</command> generates SVG graphs. In order to render those
250                 on a graphical display any SVG capable viewer can be used. It should be
251                 noted that the SVG render engines in most browsers (including Chrome
252                 and Firefox) are many times faster than dedicated graphical applications
253                 like Gimp and Inkscape.  Just point your browser at <ulink url="file:///run/log/" />!
254                 </para>
255         </refsect1>
256
257         <refsect1>
258                 <title>History</title>
259
260                 <para>This version of bootchart was implemented from
261                 scratch, but is inspired by former bootchart
262                 incantations:</para>
263
264                 <variablelist>
265                         <varlistentry>
266                                 <term><emphasis>Original bash</emphasis></term>
267                                 <listitem><para>The original bash/shell code implemented
268                                 bootchart. This version created a compressed tarball for
269                                 processing with external applications. This version did
270                                 not graph anything, only generated data.</para></listitem>
271                         </varlistentry>
272
273                         <varlistentry>
274                                 <term><emphasis>Ubuntu C Implementation</emphasis></term>
275                                 <listitem><para>This version replaced the shell version with
276                                 a fast and efficient data logger, but also did not graph
277                                 the data.</para></listitem>
278                         </varlistentry>
279
280                         <varlistentry>
281                                 <term><emphasis>Java bootchart</emphasis></term>
282                                 <listitem><para>This was the original graphing application
283                                 for charting the data, written in java.</para></listitem>
284                         </varlistentry>
285
286                         <varlistentry>
287                                 <term><emphasis>pybootchartgui.py</emphasis></term>
288                                 <listitem><para>pybootchart created a graph from the data
289                                 collected by either the bash or C version.</para></listitem>
290                         </varlistentry>
291                 </variablelist>
292
293                 <para>The version of bootchart you are using now combines both the data
294                 collection and the charting into a single application, making it more
295                 efficient and simpler. There are no longer any timing issues with the data
296                 collector and the grapher, as the graphing cannot be run until the data
297                 has been collected. Also, the data kept in memory is reduced to the absolute
298                 minimum needed.</para>
299
300         </refsect1>
301
302         <refsect1>
303                 <title>See Also</title>
304                 <para>
305                         <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
306                 </para>
307         </refsect1>
308
309         <refsect1>
310                 <title>Bugs</title>
311                 <para>systemd-bootchart does not get the model information for the hard drive
312                 unless the root device is specified with <code>root=/dev/sdxY</code>. Using
313                 UUIDs or PARTUUIDs will boot fine, but the hard drive model will not be
314                 added to the chart.</para>
315                 <para>For bugs, please contact the author and current maintainer:</para>
316                 <simplelist>
317                         <member>Auke Kok <email>auke-jan.h.kok@intel.com</email></member>
318                 </simplelist>
319         </refsect1>
320
321 </refentry>