>>>>> "JD" == Jaromir Dolecek <jdolecek@netbsd.org> writes:

JD> Is the ((MAXGDTSIZ - NGDT)/2) really needed in USER_LDT case for i386?

YES!  When a process installs its own LDT, that requires another slot in
the GDT, so the process can take up two: one for the TSS, one for the
LDT.

see sys_machdep.c:i386_set_ldt(), gdt.c:ldt_alloc(), pmap.c:pmap_fork()

-- 
==John Kohl <jtk@kolvir.arlington.ma.us>, <john_kohl@alum.mit.edu>
Home page: <http://john.kohl.home.attbi.com/>