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>-h</option></term>
 150                                <term><option>--help</option></term>
 151                                <listitem><para>Prints a short help text and exits.</para></listitem>
 152                         </varlistentry>
 153
 154                         <varlistentry>
 155                                 <term><option>-n</option></term>
 156                                 <term><option>--sample <replaceable>N</replaceable></option></term>
 157                                 <listitem><para>Specify the number of
 158                                 samples, <replaceable>N</replaceable>,
 159                                 to record. Samples will be recorded at
 160                                 intervals defined with <option>--freq</option>.
 161                                 </para></listitem>
 162                         </varlistentry>
 163
 164                         <varlistentry>
 165                                 <term><option>-f</option></term>
 166                                 <term><option>--freq <replaceable>f</replaceable></option></term>
 167                                 <listitem><para>Specify the sample log
 168                                 frequency, a positive real <replaceable>f</replaceable>, in Hz.
 169                                 Most systems can cope with values up to 25-50 without
 170                                 creating too much overhead.</para></listitem>
 171                         </varlistentry>
 172
 173                         <varlistentry>
 174                                 <term><option>-r</option></term>
 175                                 <term><option>--rel</option></term>
 176                                 <listitem><para>Use relative times instead of absolute
 177                                 times. This is useful for using bootchart at post-boot
 178                                 time to profile an already booted system. Without this
 179                                 option the graph would become extremely large. If set, the
 180                                 horizontal axis starts at the first recorded sample
 181                                 instead of time 0.0.</para></listitem>
 182                         </varlistentry>
 183
 184                         <varlistentry>
 185                                 <term><option>-F</option></term>
 186                                 <term><option>--no-filter</option></term>
 187                                 <listitem><para>Disable filtering of tasks that
 188                                 did not contribute significantly to the boot. Processes
 189                                 that are too short-lived (only seen in one sample) or
 190                                 that do not consume any significant CPU time (less than
 191                                 0.001 s) will not be displayed in the output graph.
 192                                 </para></listitem>
 193                         </varlistentry>
 194
 195                         <varlistentry>
 196                                 <term><option>-C</option></term>
 197                                 <term><option>--cmdline</option></term>
 198                                 <listitem><para>Display the full command line with arguments of processes,
 199                                 instead of only the process name.
 200                                 </para></listitem>
 201                         </varlistentry>
 202
 203                         <varlistentry>
 204                                 <term><option>-o</option></term>
 205                                 <term><option>--output <replaceable>path</replaceable></option></term>
 206                                 <listitem><para>Specify the output folder for the
 207                                 graphs. By default, bootchart writes the graphs to
 208                                 <filename>/run/log</filename>.</para></listitem>
 209                         </varlistentry>
 210
 211                         <varlistentry>
 212                                 <term><option>-i</option></term>
 213                                 <term><option>--init <replaceable>path</replaceable></option></term>
 214                                 <listitem><para>Use this init binary. Defaults to
 215                                 <command>/sbin/init</command>.
 216                                 </para></listitem>
 217                         </varlistentry>
 218
 219                         <varlistentry>
 220                                 <term><option>-p</option></term>
 221                                 <term><option>--pss</option></term>
 222                                 <listitem><para>Enable logging and graphing
 223                                 of processes' PSS (Proportional Set Size)
 224                                 memory consumption. See <filename>filesystems/proc.txt</filename>
 225                                 in the kernel documentation for an
 226                                 explanation of this field.
 227                                 </para></listitem>
 228                         </varlistentry>
 229
 230                         <varlistentry>
 231                                 <term><option>-e</option></term>
 232                                 <term><option>--entropy</option></term>
 233                                 <listitem><para>Enable logging and graphing
 234                                 of the kernel random entropy pool size.</para></listitem>
 235                         </varlistentry>
 236
 237                         <varlistentry>
 238                                 <term><option>-x</option></term>
 239                                 <term><option>--scale-x <replaceable>N</replaceable></option></term>
 240                                 <listitem><para>Horizontal scaling factor for all variable
 241                                 graph components.</para></listitem>
 242                         </varlistentry>
 243
 244                         <varlistentry>
 245                                 <term><option>-y</option></term>
 246                                 <term><option>--scale-y <replaceable>N</replaceable></option></term>
 247                                 <listitem><para>Vertical scaling factor for all variable
 248                                 graph components.</para></listitem>
 249                         </varlistentry>
 250
 251                 </variablelist>
 252
 253
 254         </refsect1>
 255
 256         <refsect1>
 257                 <title>Output</title>
 258
 259                 <para><command>systemd-bootchart</command> generates SVG graphs. In order to render those
 260                 on a graphical display any SVG capable viewer can be used. It should be
 261                 noted that the SVG render engines in most browsers (including Chrome
 262                 and Firefox) are many times faster than dedicated graphical applications
 263                 like Gimp and Inkscape.  Just point your browser at <ulink url="file:///run/log/" />!
 264                 </para>
 265         </refsect1>
 266
 267         <refsect1>
 268                 <title>History</title>
 269
 270                 <para>This version of bootchart was implemented from
 271                 scratch, but is inspired by former bootchart
 272                 incantations:</para>
 273
 274                 <variablelist>
 275                         <varlistentry>
 276                                 <term><emphasis>Original bash</emphasis></term>
 277                                 <listitem><para>The original bash/shell code implemented
 278                                 bootchart. This version created a compressed tarball for
 279                                 processing with external applications. This version did
 280                                 not graph anything, only generated data.</para></listitem>
 281                         </varlistentry>
 282
 283                         <varlistentry>
 284                                 <term><emphasis>Ubuntu C Implementation</emphasis></term>
 285                                 <listitem><para>This version replaced the shell version with
 286                                 a fast and efficient data logger, but also did not graph
 287                                 the data.</para></listitem>
 288                         </varlistentry>
 289
 290                         <varlistentry>
 291                                 <term><emphasis>Java bootchart</emphasis></term>
 292                                 <listitem><para>This was the original graphing application
 293                                 for charting the data, written in java.</para></listitem>
 294                         </varlistentry>
 295
 296                         <varlistentry>
 297                                 <term><emphasis>pybootchartgui.py</emphasis></term>
 298                                 <listitem><para>pybootchart created a graph from the data
 299                                 collected by either the bash or C version.</para></listitem>
 300                         </varlistentry>
 301                 </variablelist>
 302
 303                 <para>The version of bootchart you are using now combines both the data
 304                 collection and the charting into a single application, making it more
 305                 efficient and simpler. There are no longer any timing issues with the data
 306                 collector and the grapher, as the graphing cannot be run until the data
 307                 has been collected. Also, the data kept in memory is reduced to the absolute
 308                 minimum needed.</para>
 309
 310         </refsect1>
 311
 312         <refsect1>
 313                 <title>See Also</title>
 314                 <para>
 315                         <citerefentry><refentrytitle>bootchart.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 316                 </para>
 317         </refsect1>
 318
 319         <refsect1>
 320                 <title>Bugs</title>
 321                 <para>systemd-bootchart does not get the model information for the hard drive
 322                 unless the root device is specified with <code>root=/dev/sdxY</code>. Using
 323                 UUIDs or PARTUUIDs will boot fine, but the hard drive model will not be
 324                 added to the chart.</para>
 325                 <para>For bugs, please contact the author and current maintainer:</para>
 326                 <simplelist>
 327                         <member>Auke Kok <email>auke-jan.h.kok@intel.com</email></member>
 328                 </simplelist>
 329         </refsect1>
 330
 331 </refentry>