I think the only options are threads and malloc , so

# no threads no perls malloc
sh Configure -Uusemymalloc -Uusethreads
[download]

also maybe debug :)
http://perl.apache.org/docs/1.0/guide/performance.html
http://perl.apache.org/docs/2.0/user/install/install.html#Configuring_and_Installing_Prerequisites