Re: Time to merge scratch/correct-warning-pos into master, perhaps?

[Gregory Heytings]

> I think we need more measurements in scenarios closer to actual Emacs 
> usage.  One is intensive display operation -- I think Alan posted 
> something to that effect.  Another could be starting Gnus to read a 
> large newsgroup.  Yet another could be reindent a large piece of C or 
> Python or Lisp code.  Perhaps also "M-x occur" through a large buffer. 
> Stuff like that -- any command that tends to be used frequently and is 
> known to take a tangible amount of time.

The problem is that, IME, such benchmarks do not show anything when the 
slowdown is not significant enough (> 10%), because the measurements vary 
a lot depending on external factors.  I wonder how Alan could conclude 
that there is a slowdown of "less than 1%", when I run his benchmark on my 
(otherwise unloaded) computer, the running times I get are anywhere 
between 17s and 20s.  Taking the average of such measures does not really 
make sense.

However, I found one measurement that seems to give reasonably stable 
results.  On my Debian bookworm computer, with a standard build, on 
src/xdisp.c, (benchmark-run 100 (occur "a.b")) needs on average (with 10 
runs) 7.42 seconds (standard deviation 0.04) on 3b33a14380 and 7.66 
seconds (standard deviation 0.05) on 7922131bb2.  That's a >3% slowdown.