[tex-live] Increasing font_mem_size beyond 2000000. How?

[Gerben Wierda]

I have been trying to get a TeX which has font_mem_size beyond 
20000000. I changed sup_font_mem_size to 3000000 in pdfetex.ch, 
recompiled TeX, installed it, changed font_mem_size to 2100000 and then 
recreated all my formats (which should be unnecessary). But the closing 
statistics of my TeX run still says X out of 2000000. I can downgrade 
the 2000000 to 1900000 and it does have effect.

What am I forgetting to do?

Thanks,

G