[tex4ht] performance of tex4ht on WSL linux vs. VBox linux

[Nasser M. Abbasi]

On 11/9/2024 3:50 AM, Michal Hoftich wrote:
> Hi Nasser,
> 
> 
> make4ht --shell-escape -ulm default -a warning
>>           -f html5+join_colors -c nma_mathjax.cfg
>>           -e
>> /mnt/g/public_html/styles/texmf/tex/latex/tex4ht_build_files/MAIN.mk4
>> index.tex
>>
>>   'mathjax,htm,5,fn-in,notoc*,p-width,charset=utf-8,cut-fullname,nostyle'
>> '-cunihtf -utf8'
>>
>> --Nasser
>>
> 

> You should use the -m draft option instead of default if you want to speed
> up the compilation. This will use only one LaTeX compilation instead of
> three. The important thing is to keep the auxilary files between
> compilations, to get correct links, tables and other features. Another
> thing that can be slow is large math, because we use L3regexes in the
> MathJax mode,  so it can be slow if it needs to process large chunks of
> content.
> 
> You could run the -a debug option and watch the compilation. Does it take a
> lot of time in package loading phase? You will see a lot of
> (path/to/foo.4ht) in that phase. Or it stops when the document is
> processing? You will see [page number] messages at this phase. It can also
> stop at make4ht-lib: parse_lg process file: foo.html. Where it takes the
> most time?
> 
> Best regards,
> Michal
> 

Hello Michal;

I do not think the draft option will work. How is one supposed to
know if the build is final or not when using draft option? I using
your filter main.mk which figures how many times it needs to call tex4ht.

But any way, I think the issue seems to be using virtual box. This
slows things down. My last build on larger file took 50 hrs.

I am now trying to compare timing result on same small file I used
above but directly on windows using Miktex. But I am getting some
errors using make4ht from my config. Once I figure it out and correct it,
will post timings.

For lualatex, the result is amazing.

On windows, I get 9.4 seconds for this 500 pages PDF file

------------------------------------
G:\public_html\my_notes\ODE_algorithms>lualatex
This is LuaHBTeX, Version 1.18.1 (MiKTeX 24.4)

G:\public_html\my_notes\ODE_algorithms>ptime.exe  lualatex -halt-on-error   --shell-escape -file-line-error -interaction=batchmode index.tex

ptime 1.0 for Win32, Freeware - http://www.pc-tools.net/
Copyright(C) 2002, Jem Berkes <jberkes at pc-tools.net>

===   lualatex -halt-on-error   --shell-escape -file-line-error -interaction=batchmode index.tex ===
This is LuaHBTeX, Version 1.18.1 (MiKTeX 24.4)
  system commands enabled.

Execution time: 9.421 s
------------------------------------

On a new Virtual box, 50 GB RAM, 16 core virtual box, I get 2 minutes !

>time lualatex -halt-on-error   --shell-escape -file-line-error -interaction=batchmode index.tex
This is LuaHBTeX, Version 1.18.0 (TeX Live 2024)
  system commands enabled.

real	1m59.668s
user	0m5.363s
sys	0m2.262s
------------------------------

This is 12 times faster!

I expect similar result hopefully when I manage to run make4ht on windows.

So the slow down seems due to using Virtual box. Since disk access seems
to be much slower than when running directly on windows.

I need to get me a new PC and install Linux directlty on it and
compare timing. I expect similar timing then as on windows directly.

I can't wait 50 hrs to make a new build each time I make a new change to latex.
And this is only on one folder.

Regards,
--Nasser