From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 16 Nov 2000 13:51:01 -0200 (BRDT) From: Rik van Riel Subject: RE: KPATCH] Reserve VM for root (was: Re: Looking for better VM) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Szabolcs Szakacsits Cc: pavel-velo@bug.ucw.cz, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Ingo Molnar List-ID: On Thu, 16 Nov 2000, Szabolcs Szakacsits wrote: [snip exploit that really shouldn't take Linux down] > This or something similar didn't kill the box [I've tried all local > DoS from Packetstorm that I could find]. Please send a working > example. Of course probably it's possible to trigger root owned > processes to eat memory eagerly by user apps but that's a problem in > the process design running as root and not a kernel issue. Not necessarily, but your patch will probably make a difference for quite a number of people... > If you think fork() kills the box then ulimit the maximum number > of user processes (ulimit -u). This is a different issue and a > bad design in the scheduler (see e.g. Tru64 for a better one). My fair scheduler catches this one just fine. It hasn't been integrated in the kernel yet, but both VA Linux and Conectiva use it in their kernel RPM. > BTW, I have a new version of the patch with that Linux behaves > much better from root's point of view when the memory is more > significantly overcommited. I'll post it if I have time [and > there is interest]. There is interest, believe me ;) While this is not one of the sexy new kernel features, this will help quite a few system administrators and is destined to a long and healthy life inside kernel RPMs, maybe even in the main kernel tree (when 2.5 splits?). regards, Rik -- "What you're running that piece of shit Gnome?!?!" -- Miguel de Icaza, UKUUG 2000 http://www.conectiva.com/ http://www.surriel.com/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/