On 8/30/2023 1:16 AM, Reinhard Kotucha wrote:
On 2023-08-29 at 15:38:35 +0200, Hans Hagen wrote:
> So guess what: as i mentioned before there has been a discussion about
> portable fmt files (irr a latex request) and the normal luatex build
> script has --no-dump-share but araiks tex live doesn't do that (any
> longer) so then we get 0.020 sec per run more (2+ sec on 100 runes).
>
> (plain has a very small format so one can wonder if it's the same there
> as in other macropackages)
Hi Hans,
as far as plain TeX is concerned, I don't think that the endianmess is
the main problem. As of 2016 TeX Live loads the file UnicodeData.txt
(1.9 MB) into the format file.
i didn't say that it was for plain, although one should realize that a
format file is compressed so a the real one is a bit bigger .. reports
about 'preformance here' are mixed: plain (basically only measuring
start up time) and as well as reports on latex performance drops (which
involves loading more i guess)
If you remove the line
\input load-unicode-data.tex
from luatex.ini you probably save much more time than with
--disable-dump-share.
well, i don't have or load that file at all .. we have a plain setup
right from the beginning of the project that e use; fyi: format file
size 361K compressed, 1.44 M uncompressed. And that's what i measured with
the fact that you mention some large file being loaded (maybe that's an
inefficient one indeed) already indicates that we're talking macro
package specifics here which for me makes firther tests irrelevant
> Of course there can be other factors in a non context universe like the
> time needed to load a file database (wasn't there a upper / lowercase
> checking change recently?), fonts etc.
There are currently more than 200,000 files in texmf-dist. I've
written a script based on strace(1) which creates a tiny subset of TeX
Live in another directory containing only the files needed to process
that particular document. It's invoked like this:
I dont' have that many files although plenty fonts.
tinytex luatex myfile.tex
When I compile a plain TeX document this way the tiny TeX distribution
created by my script usually contains less than 30 files.
Plain doesn't need much.
Kpathsea needs a bit more time to locate files within a system
containing 200,000 files than within a system containing only 30 files.
The difference is measurable but negligible. Kpathsea is extremely
fast.
Good that this has been made better because in the past a full tex live
installation was good for adding seconds to startup time. SSD's and OS
file caching probably have been of help ere too.
btw, the reports hereare for linux, windows is a bit different because
there using a native vs a cross compiled binary make a difference but
let's not dive into that
> Then when we talk macro packages,
We shouldn't. If we are interested in the speed of an *engine* we
have to avoid macro packages and LaTeX by all means. LaTeX introduces
too many rooms of freedom and is a moving target.
well, now you assume all plains being the same but there is no standard
plain here and i haven't seen timings that are pure engine based apart
from startup time
For benchmarking it's best to stick with plain TeX. It's pretty easy
to create a 500+ pages lorem ipsum with a halfways reasonable text
editor.
Well, that's what I did: 1000 ipsums. But usign a plain that is not that
different from a few years back. And 0.04 sec start up difference is no
big deal given possible changes in libraries, maybe kpse, the compiler,
etc. In the early days of luatex we even noticed that sometimes adding
somethign to the engine made for a change in performance (cache hits
which was then solved by upgrading hardward) so ... also a bit of a gamble.
Hans
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Hans Hagen | PRAGMA ADE
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