# -*- after-save-hook: (org-md-export-to-markdown); -*-
#+options: toc:nil

This package collects Emacs garbage collection (GC) statistics over
time and saves it in the format that can be shared with Emacs
maintainers.

Context:
- https://yhetil.org/emacs-devel/20230310110747.4hytasakomvdyf7i@Ergus/
- https://yhetil.org/emacs-devel/87v8j6t3i9.fsf@localhost/

See the source code for information how to contact the author.

* Usage

Add
#+begin_src emacs-lisp
(require 'emacs-gc-stats)
;; Optionally reset Emacs GC settings to default values (recommended)
(setq emacs-gc-stats-gc-defaults 'emacs-defaults)
;; Optionally set reminder to upload the stats after 3 weeks.
(setq emacs-gc-stats-remind t) ; can also be a number of days
;; Optionally disable logging the command names
;; (setq emacs-gc-stats-inhibit-command-name-logging t)
(emacs-gc-stats-mode +1)
#+end_src
to your init file to enable the statistics acquiring.

When you are ready to share the results, run =M-x emacs-gc-stats-save-session=
and then share the saved ~emacs-gc-stats-file~ (defaults to
=~/.emacs.d/emacs-gc-stats.eld=) by sending an email attachment to
mailto:emacs-gc-stats@gnu.org. You can review the file before
sharing--it is a text file.

Configure ~emacs-gc-stats-remind~ to make Emacs display a reminder about
sharing the results.

* Security considerations

This package *does not* upload anything automatically.  You will need to
upload the data manually, by sending email attachment.  If necessary,
you can review ~emacs-gc-stats-file~ (defaults to
=~/.emacs.d/emacs-gc-stats.eld=) before uploading--it is just a text
file.

The following data is being collected after every command:
- GC settings ~gc-cons-threshold~ and ~gc-cons-percentage~
- Emacs version and whether Emacs framework (Doom, Prelude, etc) is used
- Whether ~gcmh-mode~ is used
- Idle time and Emacs uptime
- Available OS memory (see ~memory-info~)
- Emacs memory allocation/GC stats
- Current command name (potentially sensitive data, can be disabled)
- Timestamp when every GC is finished

Logging the command names can be disabled by setting
~emacs-gc-stats-inhibit-command-name-logging~ customization.

What exactly is being logger is controlled by
~emacs-gc-stats-setting-vars~, ~emacs-gc-stats-command-vars~, and
~emacs-gc-stats-summary-vars~.

You can use =M-x emacs-gc-stats-clear= to clear the currently collected
session data.

You can pause the logging any time by disabling ~emacs-gc-stats-mode~
(=M-x emacs-gc-stats-mode=).

* News

** Version 1.3

- New customization: ~emacs-gc-stats-inhibit-command-name-logging~ to
  disable logging current command name.  Logging is enabled by default.

- New customization: ~emacs-gc-stats-remind~ to set a reminder to share
  the data.  Reminder is disabled by default.

- The data being collected is can now be customized using
  ~emacs-gc-stats-setting-vars~, ~emacs-gc-stats-command-vars~, and
  ~emacs-gc-stats-summary-vars~.
