systemd/src/bootchart

Bootchart - a 'startup' graphing tool

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Bootchart is a tool, usually run at system startup, that collects and graphs
the CPU and disk load of the system as it works. The output of bootchart is
an SVG graph. Normally, bootchart is invoked as `bootchartd` by the kernel
by passing "init=/sbin/bootchartd" to the kernel. Bootchart will then fork
init off to resume normal system startup, while monitoring and logging
startup information in the background.

After collecting a certain amount of data (usually 15-30 seconds) the logging
stops and a graph is generated from the logged information. This graph
contains vital clues to which resources are being used, in which order, and
where possible problems exist in the startup sequence of the system.

Of course, bootchart can also be used at any moment in time to collect and
graph some data for an amount of time. Bootchart does not even require root
privileges to do so, and will happily run as a normal user. Bootchart graphs
are by default written time-stamped in /var/log.

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This version of bootchart was implemented from scratch and inspired by former
incantations of bootchart:

- The original bash/shell code implemented bootchart. This version logged all
data into a compressed tarball for later processing, and did not create a graph
on it's own.

- The C-code implementation found in Ubuntu. This version replaced above shell
code version with a faster and efficient data logger, but still did not graph
code itself.

- the original Java-based bootchart, the original graphing program that created
a bootchart graph from logged data.

- the pybootchartgui.py program, which created a graph based on the data logged
by either standalone data logger.

The version you are looking at combines these 2 parts into a single program,
which makes running it and creating graphs a bit more efficient and simple.
You can now run a single program at startup instead of 2. There are no timing
problems (the graphing stage will never run if the logging stage didn't
finish). The logged data isn't being written to disc first, then read again.
Also, the data kept in memory is reduced to the absolute minimum needed to
keep memory use low.

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Requirements: glibc. Your kernel must have procfs support and several
proc output options enabled:
  CONFIG_PROC_FS
  CONFIG_SCHEDSTATS
  CONFIG_SCHED_DEBUG
at a minimum. bootchartd itself does not require any graphics library
to generate the SVG output file.

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Configuration: please see bootchartd --help, as well as /etc/bootchartd.conf
and/or /usr/share/doc/bootchart/bootchartd.conf.example for a list of
configurable options.

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Many thanks to those who contributed ideas and code:
 - Ziga Mahkovec - Original bootchart author
 - Anders Norgaard - PyBootchartgui
 - Michael Meeks - bootchart2
 - Scott James Remnant - Ubuntu C-based logger
 - Arjan van der Ven - for the idea to merge bootgraph.pl functionality

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For bugs, please contact the author or current maintainer:
Auke Kok <auke-jan.h.kok@intel.com>

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Download bootchart releases here: http://foo-projects.org/~sofar/bootchart/
Source code is hosted here: git://github.com/sofar/bootchart