Messages in this thread | | | Subject | Re: Some questions about linux kernel. | Date | Mon, 20 Mar 2000 12:00:52 -0400 | From | Horst von Brand <> |
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orc@pell.portland.or.us (david parsons) said: > In article <linux.kernel.Pine.LNX.4.10.10003171319000.3718-100000@dax.joh.cam.ac.uk>, > James Sutherland <jas88@cam.ac.uk> 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 same. -- Dr. Horst H. von Brand mailto:vonbrand@inf.utfsm.cl 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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