LilyPond resource usage

[Hans de Rijck]

Hi developers,

Some information that may help when looking for LilyPond performance
optimisation.

When I converted a (rather large) score I noticed that Lily's resource usage
is somewhat strange.

Total conversion time: about 10 minutes.
During first 8 minutes memory usage slowly increases to 190 Mb. This is not
spectacular.
During first 8 minutes, total bytes read (that is, read from disk) increases
rapidly to 9.6 Gb. This is bizar!
Last 2 minutes, reading from disk stops, memory usage increases to 413 Mb, a
little high.

end result: PDF of 24 pages, 560 kb.

Especially the 9.6 Gbytes of disk-io is a major concern when it comes to
performance. Luckily most of it is cached (no disk light activity) but
nonetheless.

If someone is looking for possible optimisations, I would look in this
direction too.

regards,

Hans.

ps. version 2.6.3
Native windows, running Win2k