As an Emacs configuration grows, startup time can gradually increase. Measuring that increase accurately makes it easier to identify regressions. The majority of Emacs users use emacs-init-time. However, this built-in function does not measure all the work performed during startup. Emacs startup proceeds through several stages: it loads the early init and regular init files, processes command-line options, sets after-init-time, runs emacs-startup-hook, performs additional initial-frame setup such as applying frame parameters from the configuration, and then runs window-setup-hook after the initial frame parameters have been configured. This makes window-setup-hook a useful place to record a broader startup-time measurement. For a … Continue reading →