Memory usage on 9.5.0rc1 authoritive only server

[Jason Fesler]

I'm testing bind 9.50rc1 (and 9.4.2) to compare against our current  
bind version (don't laugh!).  bind8 loads our zones (roughly 20,000  
zones, and about 1.1 million records) in 350 megs of ram; bind 9.4.2  
in 550 megs of ram.

The troublesome spot seems to be setting up 9.5.0rc1 with the same  
configs as the bind 9.4.2 setup.   Once it is done loading, close to  
10 gigs of memory is claimed by named, before serving a single query.

27363 jfesler   16   0 9793m 7.6g 1528 S    0 98.0   3:14.14 named

This is running on RHEL4, on a 64 bit box, with 8 gigs of ram, with  
bind built using:

  CFLAGS='-DFD_SETSIZE=4096 -g'  LDFLAGS="-static -g"  ./configure -- 
prefix=mumble  --disable-threads

Any suggestions on how to reduce the memory usage?