Subject: Re: mapping shared memory at a fixed address
To: Daniel Carosone <>
From: Todd Vierling <>
List: netbsd-users
Date: 02/08/2005 23:29:36
On Wed, 9 Feb 2005, Daniel Carosone wrote:

> > What duplication?  All code pages are *shared* across a fork (and even the
> > data pages are shared, until a write) -- meaning that there is no
> > duplication until the pages diverge in some way between the forked
> > processes.
> I think he means that with all the program text in one address space,
> there's no more room left for the data and shm - but in separate
> executables each has enough space?

If there's that much of a squeeze for VA space, the original poster would be
better off with a LP64 machine.  However, I'm pretty sure it was just a
misunderstanding about the underlying nature of Unix VM page management.

-- Todd Vierling <> <>