man/systemd-bootchart.xml

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   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   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 analysis graphing tool</refpurpose>
  52         </refnamediv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  57                 <para>systemd-bootchart is a tool used to analyze a boot sequence.
  58                 It collects system information pertaining to the CPU and disk load, as
  59                 well as per-process information, and then creates a chart with this
  60                 information. Usually it is invoked by setting the init to
  61                 <filename>systemd-bootchart</filename> on the kernel command line. It
  62                 be run after boot to analyze running processes, though it is recommended
  63                 to use the <option>--rel</option> switch when doing this.</para>
  64
  65                 <para>After collecting a certain amount of data (default: 20 seconds) it
  66                 will write the SVG chart to <filename>/run/log</filename>. This chart
  67                 can be used to find problems in the start up sequence and where these
  68                 problems exist. It is essentially a more detailed version of the
  69                 systemd-analyze plot function.</para>
  70
  71         </refsect1>
  72
  73         <refsect1>
  74                 <title>Invocation</title>
  75
  76                 <para>systemd-bootchart can be invoked in several different ways:</para>
  77
  78                 <variablelist>
  79
  80                         <varlistentry>
  81                                 <term><emphasis>Kernel invocation</emphasis></term>
  82                                 <listitem><para>The kernel can invoke systemd-bootchart
  83                                 instead of the init process. In itself, systemd-bootchart
  84                                 will invoke <filename>/sbin/init</filename> if invoked in
  85                                 this manner.</para></listitem>
  86                         </varlistentry>
  87
  88                         <varlistentry>
  89                                 <term><emphasis>Started as a standalone program</emphasis></term>
  90                                 <listitem><para>One can execute systemd-bootchart as
  91                                 normal application from the commandline. In this mode
  92                                 it is highly recommended to pass the "-r" flag in order
  93                                 to not graph the time elapsed since boot and before
  94                                 systemd-bootchart was started, as it may result in
  95                                 extremely large graphs.
  96                                 </para></listitem>
  97                         </varlistentry>
  98                 </variablelist>
  99         </refsect1>
 100
 101         <refsect1>
 102                 <title>Options</title>
 103
 104                 <para>These options can be set globally in the <filename>/etc/systemd/bootchart.conf</filename>
 105                 file.</para>
 106
 107                 <variablelist>
 108
 109                         <varlistentry>
 110                                 <term><option>-n</option></term>
 111                                 <term><option>--sample N</option></term>
 112                                 <listitem><para>Specify the amount of samples, N, to
 113                                 record total before bootchart exits. Each sample will
 114                                 record at intervals defined by --freq.</para></listitem>
 115                         </varlistentry>
 116
 117                         <varlistentry>
 118                                 <term><option>-f</option></term>
 119                                 <term><option>--freq N</option></term>
 120                                 <listitem><para>Specify the sample log frequency, N.
 121                                 This can be a fractional number, but must be larger than
 122                                 0.0. Most systems can cope with values under 25-50 without
 123                                 creating too much overhead.</para></listitem>
 124                         </varlistentry>
 125
 126                         <varlistentry>
 127                                 <term><option>-r</option></term>
 128                                 <term><option>--rel</option></term>
 129                                 <listitem><para>Use relative times instead of absolute
 130                                 times. This is useful for using bootchart at post-boot
 131                                 time to profile an already booted system, otherwise the
 132                                 graph would become extremely large. If set, the
 133                                 horizontal axis starts at the first recorded sample
 134                                 instead of time=0.0.</para></listitem>
 135                         </varlistentry>
 136
 137                         <varlistentry>
 138                                 <term><option>-F</option></term>
 139                                 <term><option>--filter</option></term>
 140                                 <listitem><para>Disable filtering of tasks tasks that
 141                                 did not contribute significantly to the boot. Processes
 142                                 that are too short-lived (only seen in one sample) or
 143                                 that do not consume any significant CPU time (less than
 144                                 0.001sec) will not be displayed in the output graph.
 145                                 </para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><option>-o</option></term>
 150                                 <term><option>--output [path]</option></term>
 151                                 <listitem><para>Configures the output folder for writing
 152                                 the graphs. By default, bootchart writes the graphs to
 153                                 <filename>/run/log</filename>.</para></listitem>
 154                         </varlistentry>
 155
 156                         <varlistentry>
 157                                 <term><option>-i</option></term>
 158                                 <term><option>--init [path]</option></term>
 159                                 <listitem><para>Set init binary to run. Defaults to
 160                                 <filename>/sbin/init</filename>.
 161                                 </para></listitem>
 162                         </varlistentry>
 163
 164                         <varlistentry>
 165                                 <term><option>-p</option></term>
 166                                 <term><option>--pss</option></term>
 167                                 <listitem><para>Enable logging and graphing
 168                                 of processes PSS memory consumption.</para></listitem>
 169                         </varlistentry>
 170
 171                         <varlistentry>
 172                                 <term><option>-e</option></term>
 173                                 <term><option>--entropy</option></term>
 174                                 <listitem><para>Enable logging and graphing
 175                                 of the kernel random entropy pool size.</para></listitem>
 176                         </varlistentry>
 177
 178                         <varlistentry>
 179                                 <term><option>-x</option></term>
 180                                 <term><option>--scale-x N</option></term>
 181                                 <listitem><para>Horizontal scaling factor for all variable
 182                                 graph components.</para></listitem>
 183                         </varlistentry>
 184
 185                         <varlistentry>
 186                                 <term><option>-y</option></term>
 187                                 <term><option>--scale-y N</option></term>
 188                                 <listitem><para>Vertical scaling factor for all variable
 189                                 graph components.</para></listitem>
 190                         </varlistentry>
 191
 192                 </variablelist>
 193
 194
 195         </refsect1>
 196
 197         <refsect1>
 198                 <title>Output</title>
 199
 200                 <para>systemd-bootchart generates SVG graphs. In order to render these
 201                 on a graphical display any SVG capable viewer can be used. It should be
 202                 noted that the SVG render engines in most browsers (including Chrome
 203                 and Firefox) are many times faster than dedicated graphical applications
 204                 like Gimp and Inkscape.  Just point your browser at "file:///run/log"!
 205                 </para>
 206         </refsect1>
 207
 208         <refsect1>
 209                 <title>History</title>
 210
 211                 <para>This version of bootchart was implemented from scratch, but inspired
 212                   by former bootchart incantations:</para>
 213
 214                 <variablelist>
 215                         <varlistentry>
 216                                 <term><emphasis>Original bash</emphasis></term>
 217                                 <listitem><para>The original bash/shell code implemented
 218                                 bootchart. This version created a compressed tarball for
 219                                 processing with external applications. This version did
 220                                 not graph anything, only generated data.</para></listitem>
 221                         </varlistentry>
 222
 223                         <varlistentry>
 224                                 <term><emphasis>Ubuntu C Implementation</emphasis></term>
 225                                 <listitem><para>This version replaced the shell version with
 226                                 a fast and efficient data logger, but also did not graph
 227                                 the data.</para></listitem>
 228                         </varlistentry>
 229
 230                         <varlistentry>
 231                                 <term><emphasis>Java bootchart</emphasis></term>
 232                                 <listitem><para>This was the original graphing application
 233                                 for charting the data, written in java.</para></listitem>
 234                         </varlistentry>
 235
 236                         <varlistentry>
 237                                 <term><emphasis>pybootchartgui.py</emphasis></term>
 238                                 <listitem><para>pybootchart created a graph from the data
 239                                 collected by either the bash or C version.</para></listitem>
 240                         </varlistentry>
 241                 </variablelist>
 242
 243                 <para>The version of bootchart you are using now combines both the data
 244                 collection and the charting into a single application, making it more
 245                 efficient and simpler. There are no longer any timing issues with the data
 246                 collector and the grapher, as the graphing cannot be run until the data
 247                 has been collected. Also, the data kept in memory is reduced to the absolute
 248                 minimum needed.</para>
 249
 250
 251         </refsect1>
 252
 253         <refsect1>
 254                 <title>See Also</title>
 255                 <para>
 256                         <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 257                 </para>
 258         </refsect1>
 259
 260         <refsect1>
 261                 <title>Bugs</title>
 262                 <para>For bugs, please contact the author or current maintainer:</para>
 263                 <varlistentry>
 264                         <term>Auke Kok</term>
 265                         <term><emphasis>auke-jan.h.kok@intel.com</emphasis></term>
 266                 </varlistentry>
 267         </refsect1>
 268
 269 </refentry>