Re: Long Compile time with version 2.19.44

[David Wright]

On Thu 07 Jul 2016 at 15:15:42 (-0700), BGM wrote:
> Well, it seems like it hangs on just starting lilypond.  (and, as I've
> mentioned, I didn't have this problem with version 2.18)
> 
> As soon as it gets past this line...
> So, this line takes 99% of the time in the progressbar:
> Starting lilypond-windows.exe 2.19.44 [whatever.ly]...
> 
> then all the rest progresses nice and fast.
> 
> Processing `C:/hymns/whatever.ly'
> Parsing...
> Interpreting music...[8][16]
> Preprocessing graphical objects...
> Interpreting music...
> MIDI output to `whatever.mid'...
> Finding the ideal number of pages...
> Fitting music on 1 page...
> Drawing systems...
> Layout output to `./tmp-lilypond-WYGD9b'...
> Converting to `whatever.pdf'...
> Deleting `./tmp-lilypond-WYGD9b'...
> Success: compilation successfully completed
> Completed successfully in 30.0".

Here are some timings off a reasonably sized carol that generates
seven MIDI files and three PDFs. Old and new versions alternate
(2.18.2 and 2.19.42).

# echo 3 > /proc/sys/vm/drop_caches

real    0m33.921s
user    0m20.040s
sys     0m0.716s

real    0m28.471s
user    0m17.696s
sys     0m0.756s

real    0m20.586s
user    0m19.832s
sys     0m0.556s

real    0m18.838s
user    0m17.600s
sys     0m0.744s

real    0m20.535s
user    0m19.800s
sys     0m0.596s

real    0m18.677s
user    0m17.456s
sys     0m0.844s

So the new version wins by about two seconds.

Note the difference that caching the program makes. You've got to run
a program twice (at least) to get a realistic time.

I always put all the structure of my scores in \score;
ie I don't write   variable = \new ...
so I have no comparative data. However, if you try doing
this, remember again to run both versions twice or you may
only be measuring the efficiency of the operating system.

Cheers,
David.