How can I set up bootchart in Ubuntu 15.10? [duplicate]

Question

This question already has an answer here:

• How to access the grub boot menu in order to generate bootchart? 1 answer

This page says that I have to edit the "linux" line in the grub boot menu to set up bootchart. I do not understand what exactly it is that I have to do. Please help.

Answer 1

You don't need to do that any more in 15.10 or any other Ubuntu release booting with systemd. It automatically records the necessary information on every boot and allows you to analyse it with the command

systemd-analyze

The argument to get a graphical bootchart as SVG image is:

systemd-analyze plot > filename.svg

But it has also other useful commands. You see a list of possible arguments by entering systemd-analyze and pressing Tab twice using the Bash autocompletion, or old-style by opening the manual page with man systemd-analyze or showing the help with systemd-analyze --help.
Here's a list of the commands. Default is time, if you don't specify any other:

Commands:
  time                    Print time spent in the kernel
  blame                   Print list of running units ordered by time to init
  critical-chain          Print a tree of the time critical chain of units
  plot                    Output SVG graphic showing service initialization
  dot                     Output dependency graph in dot(1) format
  set-log-level LEVEL     Set logging threshold for systemd
  dump                    Output state serialization of service manager
  verify FILE...          Check unit files for correctness