Re: scratch/accurate-warning-pos: Solid progress: the branch now bootstraps.

[Gemini Lasswell <gazally@runbox.com>]

Alan Mackenzie <acm@muc.de> writes:

Hi Alan,

> syntax-tasks-{backward,forward}-word presumably time backward-word and
> forward-word.  bytecomp-tasks-compile-doc I'm not sure about, is that
> the extraction of doc strings from .elc files?

You are correct about syntax-tasks-*.  bytecomp-tasks-compile-doc
measures the time it takes to compile the function 'doctor-doc' from
doctor.el (since I want benchmark tasks to run in old versions of Emacs,
I went looking in lisp/play for something that hadn't changed in a long
time.)

> After getting over my knee-jerk reaction, my thoughts are that these
> timings are not of things which, of themselves, would directly concern a
> user.  A fill-paragraph will take 15% more time, but would a user
> actually notice this, given that the operation is usually instantaneous?
>
> Good things to benchmark would be interactive commands which feel a bit
> sluggish anyway.  CC Mode redisplay is a good candidate for this (see
> below).  ;-)
>
> From your timings, my gut feeling is that the 15% slowdown in
> fill-tasks-fill-paragraph probably represents fairly closely the
> slowdown in Emacs as a whole.  It is testing a "macro" operation rather
> than an isolated primitive.

Every time I use a keyboard macro to edit every line in a file, I wonder
why it takes so long.  kmacro-tasks-edit-lines changes 10 lines of
"1. Flintstone, Fred" to read "Fred Flintstone" using basic editing
commands.  From the current short list of benchmarks, it would be my
choice for representing Emacs as a whole.

> My 8% (approximate) I measured by scrolling through xdisp.c, displaying
> each window's worth on the way.  Before repeating this timing, it's
> necessary to insert a character at BOB then undo the insertion, so as to
> erase the face and other properties throughout the buffer.
>
> Perhaps you might be able to adapt this exercise into your branch.  At
> any rate, I'd be interested if you could compare the timings on your
> machine between old and new Emacs versions.

Thanks for the suggestion and the code.  The benchmark numbers in my
last email were all created with --batch, meaning no display.  But
running benchmarks without --batch, so that redisplay can be
benchmarked, is one of the things I'm working on.