bug#37321: 27.0.50; Excessive gc in a use case (el-search)

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Date: Thu, 26 Sep 2019 13:42:02 +0200
> Cc: 37321@debbugs.gnu.org
> 
> > That is, if you are observing significantly better performance with
> > gc-cons-percentage set to 0.8, shouldn't we set it to be that value by
> > default in Emacs?
> 
> Good question.  Could it have downsides (I guess garbage collection
> would happen less often but take longer then so one could get noticeable
> interrupts)?

Using 0.8 means we won't GC before we cons 80% of the heap, which
sounds too high.

Btw, any reason why you enlarge gc-cons-percentage instead of
gc-cons-threshold?  The former is less determinate because it depends
on the size of the heap, which you cannot control.