man/systemd-bootchart.xml

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   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                         and saved to the journal with
  97                         <varname>MESSAGE_ID=9f26aa562cf440c2b16c773d0479b518</varname>.
  98                         Journal field <varname>BOOTCHART=</varname> contains
  99                         the bootchart in SVG format.
 100                 </para>
 101
 102         </refsect1>
 103
 104         <refsect1>
 105                 <title>Invocation</title>
 106
 107                 <para><command>systemd-bootchart</command> can be invoked in several different ways:</para>
 108
 109                 <variablelist>
 110
 111                         <varlistentry>
 112                                 <term><emphasis>Kernel invocation</emphasis></term>
 113                                 <listitem><para>The kernel can invoke
 114                                 <command>systemd-bootchart</command>
 115                                 instead of the init process. In turn,
 116                                 <command>systemd-bootchart</command>
 117                                 will invoke <command>/sbin/init</command>.
 118                                 </para></listitem>
 119                         </varlistentry>
 120
 121                         <varlistentry>
 122                                 <term><emphasis>Started as a standalone program</emphasis></term>
 123                                 <listitem><para>One can execute
 124                                 <command>systemd-bootchart</command>
 125                                 as normal application from the
 126                                 commandline. In this mode it is highly
 127                                 recommended to pass the
 128                                 <option>-r</option> flag in order to
 129                                 not graph the time elapsed since boot
 130                                 and before systemd-bootchart was
 131                                 started, as it may result in extremely
 132                                 large graphs.  </para></listitem>
 133                         </varlistentry>
 134                 </variablelist>
 135         </refsect1>
 136
 137         <refsect1>
 138                 <title>Options</title>
 139
 140                 <para>These options can also be set in the
 141                 <filename>/etc/systemd/bootchart.conf</filename>
 142                 file. See
 143                 <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 144                 </para>
 145
 146                 <variablelist>
 147
 148                         <varlistentry>
 149                                 <term><option>-n</option></term>
 150                                 <term><option>--sample <replaceable>N</replaceable></option></term>
 151                                 <listitem><para>Specify the number of
 152                                 samples, <replaceable>N</replaceable>,
 153                                 to record. Samples will be recorded at
 154                                 intervals defined with <option>--freq</option>.
 155                                 </para></listitem>
 156                         </varlistentry>
 157
 158                         <varlistentry>
 159                                 <term><option>-f</option></term>
 160                                 <term><option>--freq <replaceable>f</replaceable></option></term>
 161                                 <listitem><para>Specify the sample log
 162                                 frequency, a positive real <replaceable>f</replaceable>, in Hz.
 163                                 Most systems can cope with values up to 25-50 without
 164                                 creating too much overhead.</para></listitem>
 165                         </varlistentry>
 166
 167                         <varlistentry>
 168                                 <term><option>-r</option></term>
 169                                 <term><option>--rel</option></term>
 170                                 <listitem><para>Use relative times instead of absolute
 171                                 times. This is useful for using bootchart at post-boot
 172                                 time to profile an already booted system. Without this
 173                                 option the graph would become extremely large. If set, the
 174                                 horizontal axis starts at the first recorded sample
 175                                 instead of time 0.0.</para></listitem>
 176                         </varlistentry>
 177
 178                         <varlistentry>
 179                                 <term><option>-F</option></term>
 180                                 <term><option>--no-filter</option></term>
 181                                 <listitem><para>Disable filtering of tasks that
 182                                 did not contribute significantly to the boot. Processes
 183                                 that are too short-lived (only seen in one sample) or
 184                                 that do not consume any significant CPU time (less than
 185                                 0.001 s) will not be displayed in the output graph.
 186                                 </para></listitem>
 187                         </varlistentry>
 188
 189                         <varlistentry>
 190                                 <term><option>-C</option></term>
 191                                 <term><option>--cmdline</option></term>
 192                                 <listitem><para>Display the full command line with arguments of processes,
 193                                 instead of only the process name.
 194                                 </para></listitem>
 195                         </varlistentry>
 196
 197                         <varlistentry>
 198                                 <term><option>-o</option></term>
 199                                 <term><option>--output <replaceable>path</replaceable></option></term>
 200                                 <listitem><para>Specify the output folder for the
 201                                 graphs. By default, bootchart writes the graphs to
 202                                 <filename>/run/log</filename>.</para></listitem>
 203                         </varlistentry>
 204
 205                         <varlistentry>
 206                                 <term><option>-i</option></term>
 207                                 <term><option>--init <replaceable>path</replaceable></option></term>
 208                                 <listitem><para>Use this init binary. Defaults to
 209                                 <command>/sbin/init</command>.
 210                                 </para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>-p</option></term>
 215                                 <term><option>--pss</option></term>
 216                                 <listitem><para>Enable logging and graphing
 217                                 of processes' PSS (Proportional Set Size)
 218                                 memory consumption. See <filename>filesystems/proc.txt</filename>
 219                                 in the kernel documentation for an
 220                                 explanation of this field.
 221                                 </para></listitem>
 222                         </varlistentry>
 223
 224                         <varlistentry>
 225                                 <term><option>-e</option></term>
 226                                 <term><option>--entropy</option></term>
 227                                 <listitem><para>Enable logging and graphing
 228                                 of the kernel random entropy pool size.</para></listitem>
 229                         </varlistentry>
 230
 231                         <varlistentry>
 232                                 <term><option>-x</option></term>
 233                                 <term><option>--scale-x <replaceable>N</replaceable></option></term>
 234                                 <listitem><para>Horizontal scaling factor for all variable
 235                                 graph components.</para></listitem>
 236                         </varlistentry>
 237
 238                         <varlistentry>
 239                                 <term><option>-y</option></term>
 240                                 <term><option>--scale-y <replaceable>N</replaceable></option></term>
 241                                 <listitem><para>Vertical scaling factor for all variable
 242                                 graph components.</para></listitem>
 243                         </varlistentry>
 244
 245                 </variablelist>
 246
 247
 248         </refsect1>
 249
 250         <refsect1>
 251                 <title>Output</title>
 252
 253                 <para><command>systemd-bootchart</command> generates SVG graphs. In order to render those
 254                 on a graphical display any SVG capable viewer can be used. It should be
 255                 noted that the SVG render engines in most browsers (including Chrome
 256                 and Firefox) are many times faster than dedicated graphical applications
 257                 like Gimp and Inkscape.  Just point your browser at <ulink url="file:///run/log/" />!
 258                 </para>
 259         </refsect1>
 260
 261         <refsect1>
 262                 <title>History</title>
 263
 264                 <para>This version of bootchart was implemented from
 265                 scratch, but is inspired by former bootchart
 266                 incantations:</para>
 267
 268                 <variablelist>
 269                         <varlistentry>
 270                                 <term><emphasis>Original bash</emphasis></term>
 271                                 <listitem><para>The original bash/shell code implemented
 272                                 bootchart. This version created a compressed tarball for
 273                                 processing with external applications. This version did
 274                                 not graph anything, only generated data.</para></listitem>
 275                         </varlistentry>
 276
 277                         <varlistentry>
 278                                 <term><emphasis>Ubuntu C Implementation</emphasis></term>
 279                                 <listitem><para>This version replaced the shell version with
 280                                 a fast and efficient data logger, but also did not graph
 281                                 the data.</para></listitem>
 282                         </varlistentry>
 283
 284                         <varlistentry>
 285                                 <term><emphasis>Java bootchart</emphasis></term>
 286                                 <listitem><para>This was the original graphing application
 287                                 for charting the data, written in java.</para></listitem>
 288                         </varlistentry>
 289
 290                         <varlistentry>
 291                                 <term><emphasis>pybootchartgui.py</emphasis></term>
 292                                 <listitem><para>pybootchart created a graph from the data
 293                                 collected by either the bash or C version.</para></listitem>
 294                         </varlistentry>
 295                 </variablelist>
 296
 297                 <para>The version of bootchart you are using now combines both the data
 298                 collection and the charting into a single application, making it more
 299                 efficient and simpler. There are no longer any timing issues with the data
 300                 collector and the grapher, as the graphing cannot be run until the data
 301                 has been collected. Also, the data kept in memory is reduced to the absolute
 302                 minimum needed.</para>
 303
 304         </refsect1>
 305
 306         <refsect1>
 307                 <title>See Also</title>
 308                 <para>
 309                         <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 310                 </para>
 311         </refsect1>
 312
 313         <refsect1>
 314                 <title>Bugs</title>
 315                 <para>systemd-bootchart does not get the model information for the hard drive
 316                 unless the root device is specified with <code>root=/dev/sdxY</code>. Using
 317                 UUIDs or PARTUUIDs will boot fine, but the hard drive model will not be
 318                 added to the chart.</para>
 319                 <para>For bugs, please contact the author and current maintainer:</para>
 320                 <simplelist>
 321                         <member>Auke Kok <email>auke-jan.h.kok@intel.com</email></member>
 322                 </simplelist>
 323         </refsect1>
 324
 325 </refentry>