vicvbcun wrote 1 months ago
(address . bug-guix@gnu.org)
Z5dfkh14ZyWISprI@lambda
Hello Guix!
Consider the following example latex document:
Toggle snippet (7 lines)
\documentclass{article}
\usepackage{mathtools}
\begin{document}
hello world
\end{document}
Compiling it with LuaLaTeX under strace in a shell with
texlive-scheme-basic, texlive-collection-luatex and
texlive-collection-latexextra, it seems like most of the time is spent
recursively searching for input files:
Toggle snippet (10 lines)
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
27.70 0.080138 2 30174 getdents64
21.99 0.063605 4 15455 259 openat
17.44 0.050460 3 16179 32 newfstatat
14.37 0.041583 3 10440 10296 access
8.42 0.024348 1 15196 close
7.76 0.022456 1 15201 fstat
0.79 0.002278 1 1868 write
and similarly for pdflatex.
As an extreme example, consider
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\documentclass{tudapub}
\begin{document}
hello world
\end{document}
compiled with
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texlive-scheme-basic
texlive-collection-luatex
texlive-collection-latexextra
texlive-roboto texlive-urcls
texlive-xcharter
texlive-tuda-ci
This takes over 14 seconds (compared to about 2.7 seconds for lualatex
from Arch Linux) and from strace:
Toggle snippet (11 lines)
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
32.60 5.926537 3 1801518 getdents64
26.46 4.809462 5 900841 284 openat
20.90 3.799744 4 896057 895349 access
10.19 1.851520 2 900557 close
9.49 1.724891 1 900575 fstat
0.28 0.050743 2 17680 229 newfstatat
0.04 0.007077 1 6073 read
The cause for this seems to be kpathsea doesn't treat the ls-R database
as authoritative. It is opened but kpathsea falls back to recursive
searching.
In the package definition for texlive-libkpathsea, texmf.cnf is modified
such that the TEXMF variable is set without !! in front of
$TEXMFSYSCONFIG, $TEXMFSYSVAR and $TEXMFDIST.
If I override $TEXMF via --cnf-line like
Toggle snippet (5 lines)
lualatex \
--cnf-line='TEXMF =
{$TEXMFCONFIG,$TEXMFVAR,$TEXMFHOME,!!$TEXMFSYSCONFIG,!!$TEXMFSYSVAR,!!$TEXMFDIST}' \
example.ltx
compilation time for the extreme example above falls to about 2.5
seconds, without excessive searching.
The comment above the substitution says that the !! construct wouldn't
work for texlive-build-system or when building profiles. I don't know
if it would be possible to work around this but perhaps it could be
possible to work around this if installed in profile (or environment)?
vicvbcun