Subject: Re: sparse core dumps?
To: Matt Thomas <>
From: Nathan J. Williams <>
List: tech-kern
Date: 06/02/2004 18:31:01
Matt Thomas <> writes:

> I've proposed before that a read-only access to a demand zero page does
> not allocate a new page, but instead generates a copy-on-write reference
> to a zero-page.  (instead of allocating a free page and placing a
> writable page into the vmspace).

That's a somewhat different problem; the memory doesn't have to have
even been read, as in Hubert's example, or in a mmap(MAP_ANON).

> The other alternative is to make the coredump code much more
> knowledgeable about uvm internals so it can create sections akin to
> .bss (ALLOC but no CONTENTS).


        - Nathan