GNU bug report logs - #36597
27.0.50; rehash hash tables eagerly in pdumper

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Package: emacs;

Reported by: Pip Cet <pipcet <at> gmail.com>

Date: Thu, 11 Jul 2019 14:07:02 UTC

Severity: normal

Tags: patch

Found in version 27.0.50

Done: Paul Eggert <eggert <at> cs.ucla.edu>

Bug is archived. No further changes may be made.

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From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Pip Cet <pipcet <at> gmail.com>
Cc: 36597 <at> debbugs.gnu.org, Daniel Colascione <dancol <at> dancol.org>
Subject: bug#36597: 27.0.50; rehash hash tables eagerly in pdumper
Date: Sun, 14 Jul 2019 08:49:16 -0700
Pip Cet wrote:
> Indeed, that's plenty of small Emacs processes not doing very much.
> It's not the case we ought to be optimizing for, I think, but the
> performance concerns should be taken seriously.

What's a good benchmark for what we should be optimizing for? Ideally something 
somewhat-realistic as opposed to a microbenchmark.

It doesn't appear to be as simple as plenty of processes not doing very much. 
This benchmark:

cd leim && time make -B ../lisp/leim/ja-dic/ja-dic.el

is dominated by a single CPU-intensive Emacs process and takes about 19 CPU 
seconds on my home desktop. The proposed patch slows this benchmark down by 
about 0.6%. (I ran the benchmark ten times after a warmup run, and took the 
average of the ten user+system times.)




This bug report was last modified 4 years and 284 days ago.

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