systemd Developer Auke Kok auke-jan.h.kok@intel.com systemd-bootchart 1 systemd-bootchart Boot performance analysis graphing tool Systemd-bootchart is an boot time analysis tool. It represents various aspects of the system as graph elements. These graph elements allow the user to determine resource usage, efficiency and performance issues. systemd-bootchart can be invoked in several different ways: The kernel can invoke systemd-bootchart instead of the init process. In itself, systemd-bootchart will invoke /sbin/init if invoked in this matter. One can execute systemd-bootchart as normal application from the commandline. In this mode it is highly recommended to pass the "-r" flag in order to not graph the time elapsed since boot and before systemd-bootchart was started, as it may result in extremely large graphs. -n --sample N Specify the amount of samples to record total before bootchart exits. Each sample will record at intervals defined by --freq. -f --freq N Specify the sample log frequency. This can be a fractional number, but must be larger than 0.0. Most systems can cope with values under 25-50 without impacting boot time severely. -r --rel Use relative times instead of absolute times. This is useful for using bootchart at post-boot time to profile an already booted system, otherwise the graph would become extremely large. If set, the horizontal axis starts at the first recorded sample instead of time=0.0. -F --filter Disable filtering of tasks tasks that did not contribute significantly to the boot. Processes that are too short-lived (only seen in one sample) or that do not consume any significant CPU time (less than 0.001sec) will not be displayed in the output graph. -o --output [path] Configures the output folder for writing the graphs. By default, bootchart writes the graphs to /run/log. -i --init [path] Set init binary to run. Defaults to /sbin/init. -p --pss Enable logging and graphing of processes PSS memory consumption. -e --entropy Enable logging and graphing of the kernel random entropy pool size. -x --scale-x N Horizontal scaling factor for all variable graph components. -y --scale-y N Vertical scaling factor for all variable graph components. Systemd-bootchart generates SVG graphs. In order to render these on a graphical display any SVG capable viewer can be used. It should be noted that the SVG render engines in most browsers (including Chrome and Firefox) are many times faster than dedicated graphical applications like Gimp and Inkscape. Just point your browser at "file:///var/log"! bootchart.conf5