what does the driver do for mmap and munmap?

Hi,

I'm using GM 1.4 on Solaris 8, running on a cluster of Pentiums. I'm 
trying to find out why gm_close takes as long as it does (40 ms), and so 
far I've found out that the bulk of it is in calls to munmap. I've also 
discovered that large mmaps (>= 1 MB) also take huge amounts of time (on 
the order of milliseconds).

I need to understand: What does the GM driver do when mmap / munmap are 
called?

Thanks for your help.

-- 
  Israel Hsu
  israel @ cs . ucla . edu
  israelh @ u . washington . edu