Subject: Re: mapping shared memory at a fixed address
To: Rahul Kulkarni <>
From: Bill Studenmund <>
List: netbsd-users
Date: 02/08/2005 15:03:59
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On Tue, Feb 08, 2005 at 02:28:47PM -0800, Rahul Kulkarni wrote:
> On a potentially large system with a huge code base,
> this cannot work, due to a lot of duplication in the
> text and if if you fork a lot of children then the
> text  sizes will be a concern..=20

If you have something you want usable in a huge code base, I think you're
much more likely to run into issues with the address range not being
available. You may be lucky, and something around 2 GB or so in the VA=20
will be fine. Or something around 1 GB maybe. Depends on how big your=20
programs and libs are and how big your heap usage is. Also, I think we now=
have a top-down heap, so the middle is open.

Also, I assume you're running on an ILP32 system (x86, so on). If you're=20
on an LP64, you will probably have no problem. :-)

Look at X and other things that already do shared-memory transport.

Take care,


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