man/systemd-bootchart.xml

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   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
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  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/>.
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  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>