Re: Indentation and gc

[Ergus]

On Sat, Mar 11, 2023 at 10:54:24AM +0000, Ihor Radchenko wrote:
> Eli Zaretskii <eliz@gnu.org> writes:
>
> > > ;; Make gc pauses faster by decreasing the threshold again (from the increased 
> > > initial).
> > > (setq gc-cons-threshold (* 20 1024 1024))
> > > ;; original value: 800 000
> > >
> > > ;; speed up reading from external processes
> > > (setq read-process-output-max (* 1024 1024)) ;; 1mb
> >
> > This can only be done around specific portions of code known in
> > advance to be long and GC-intensive.  I don't think this kind of
> > technique can be used in the situation described by the OP.
>
> May it be done when loading init.el and early-init.el?
> Init files are commonly known to be resource-intensive. They also tend
> to trigger GC more because the heap size is not yet very large and thus
> `gc-cons-percentage' does not yet take precedence over `gc-cons-threshold'.
>
> As for "known in advance", may Emacs keep track of how many GCs are
> triggered by user commands and then adjust GC dynamically?

Hi Ihor:

I have this in my early-init since a few years now.


```
(defconst my/file-name-handler-alist file-name-handler-alist)
(defconst my/gc-cons-threshold (* 2 gc-cons-threshold))

(setq-default file-name-handler-alist nil
              gc-cons-threshold most-positive-fixnum   ;; Defer Garbage 
collection
              gc-cons-percentage 1.0
              message-log-max 16384)

(add-hook 'window-setup-hook
          (lambda ()
            (setq file-name-handler-alist my/file-name-handler-alist
                  gc-cons-threshold my/gc-cons-threshold
                  gc-cons-percentage 0.1)
            (let ((curtime (current-time)))
              (message "Times: init:%.06f total:%.06f gc-done:%d"
                       (float-time (time-subtract after-init-time 
before-init-time))
                       (float-time (time-subtract curtime before-init-time))
                       gcs-done)))
          90)
```

This reduced my load time by 50% on GNU/Linux (a bit more indeed)... on
MS-Windows I am still above the 7 seconds with exactly same config (so
more than 14x slower than GNU/Linux... but I guess the problem is maybe
outside GNU Linux... antivirus virus and MS process creation slowness.)


> --
> Ihor Radchenko // yantar92,
> Org mode contributor,
> Learn more about Org mode at <https://orgmode.org/>.
> Support Org development at <https://liberapay.com/org-mode>,
> or support my work at <https://liberapay.com/yantar92>