garbage collection slowdown

[Han-Wen Nienhuys]

Hi folks,

after a long hiatus I have started getting involved with LilyPond
again, and one of the things I'd like to do is get LilyPond off GUILE
1.8. Experiments suggest that starting from GUILE 2.2, the execution
performance is on par with 1.8. There are 2 open issues:  caching byte
compiled files (which I haven't looked into yet), and GC.

Unfortunately, it looks like the adoption of the BDW GC library caused
a ~6x slowdown, causing an overall end-to-end slowdown of 50%.

I was wondering if you folks would have tips to further tune GC for
wall-time speed, and if there additional diagnostics to see if we're
doing something extraordinarily silly.

I already found the GC_free_space_divisor, but I already tuned to its
fastest value, 1.

--
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen