GNU bug report logs -
#25706
26.0.50; Slow C file fontification
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Reported by: Sujith <m.sujith <at> gmail.com>
Date: Mon, 13 Feb 2017 18:41:01 UTC
Severity: normal
Tags: moreinfo
Found in version 26.0.50
Done: Alan Mackenzie <acm <at> muc.de>
Bug is archived. No further changes may be made.
Full log
Message #137 received at 25706 <at> debbugs.gnu.org (full text, mbox):
Alan Mackenzie <acm <at> muc.de> writes:
> Have you got the option fast-but-imprecise-scrolling set (or customized)
> to non-nil? If not, could I suggest you try it. It's effect is to stop
> Emacs fontifying every screen it scrolls over, instead only fontifying
> screens when it's got no more input commands waiting. This speeds
> things up quite a bit on a slower machine.
Turning on fast-but-imprecise-scrolling improves things by a lot.
Viewing and scrolling the osprey file is much faster/smoother and the
screen doesn't freeze.
> Please put the following code into your *scratch* buffer (it's the same
> code I've posted before) and evaluate it:
>
> (defmacro time-it (&rest forms)
> "Time the running of a sequence of forms using `float-time'.
> Call like this: \"M-: (time-it (foo ...) (bar ...) ...)\"."
> `(let ((start (float-time)))
> ,@forms
> (- (float-time) start)))
>
> Then please load osprey_reg_map_macro.h freshly into a buffer, and type
> (or cut and paste) the following into M-:
>
> (time-it (let ((n 10)) (while (> n 0) (scroll-up) (sit-for 0) (setq n (1- n)))))
>
> What is the reported timing for scrolling these ten screens?
Running emacs -Q (master + 3 patches) :
With fast-but-imprecise-scrolling: 0.9250097274780273
Without fast-but-imprecise-scrolling: 0.8903303146362305
I think using the fast-but-imprecise-scrolling option
is a workaround that can be used in underpowered machines
for big header files...
This bug report was last modified 4 years and 212 days ago.
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