Re: Some questions about linux kernel.

From: Horst von Brand (
Date: Mon Mar 20 2000 - 11:00:52 EST (david parsons) said:
> In article <>,
> James Sutherland <> wrote:


> >In fact, it makes the problem worse.
> If the problem is an intruder on your system who is attempting a
> deliberate denial of service attack, maybe. If the problem is a
> program allocating more memory than there is in the system and
> making a different program die because of the overcommit,
> non-overcommit is the best solution to this feature.

If one program allocates just shy of what is available, it will succeed.
The next one the can't get the memory it needs and crashes. Exactly as in
the overcommiting case: Innocent bystanders get shot, just earlier (or even
much earlier) if you don't overcommit. And with a clean bullet through the
head (malloc(3), or fork(2), fails), not by a random shot at the body
(SIGSEGV when accessing memory that "should be there"). End result is the

Dr. Horst H. von Brand             
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513

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