bug#29095: Bug: The '20a09de953f437109a098fa8c4d380663d921481' merge increased my Emacs configuration loading time from 9 s to 60 s

[Eli Zaretskii]

> From: Alexander Shukaev <emacs@Alexander.Shukaev.name>
> Date: Wed, 1 Nov 2017 01:44:50 +0100
> 
> Decided to try pretest of 26.0.90 and immediately discovered that it is 
> slower than, for example, 'e7f65187580342171dd9ad32e570c50c96badb13' 
> which I used before.  In particular, thanks to a couple of hours of 
> bisecting, I found that the '20a09de953f437109a098fa8c4d380663d921481' 
> merge increased my Emacs configuration loading time from 9 s to 60 s, 

By "Emacs configuration loading time" you mean the time it takes Emacs
to start up when you type "emacs" at the shell prompt?  Or do you mean
something else?

> which is unacceptable.  I have no idea how this made it's way to the 
> 'master' branch.  Furthermore, other operations like navigation across 
> windows or performing an incremental search are also noticeably slower, 
> i.e. they stutter annoyingly

Is your build optimized or unoptimized?  If the latter, perhaps your
previous build was optimized?  The difference between them could be a
factor of 2.5 in speed.

> and from what I see is a result of extensive GC spam which did not
> occur in previous versions.

What do you mean by "extensive GC spam"?

Also, in what major mode(s) and what kind of files do you see this
performance degradation?

Thanks.