From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 10 Oct 2000 12:30:51 -0300 (BRST) From: Rik van Riel Subject: Re: [PATCH] VM fix for 2.4.0-test9 & OOM handler In-Reply-To: <20001010162412.E3386@parcelfarce.linux.theplanet.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Philipp Rumpf Cc: Andrea Arcangeli , Ingo Molnar , Byron Stanoszek , Linus Torvalds , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 10 Oct 2000, Philipp Rumpf wrote: > On Tue, Oct 10, 2000 at 12:06:07PM -0300, Rik van Riel wrote: > > On Tue, 10 Oct 2000, Philipp Rumpf wrote: > > > > > The algorithm you posted on the list in this thread will kill > > > > > init if on 4Mbyte machine without swap init is large 3 Mbytes > > > > > and you execute a task that grows over 1M. > > > > > > > > This sounds suspiciously like the description of a DEAD system ;) > > > > > > But wouldn't a watchdog daemon which doesn't allocate any memory > > > still get run ? > > > > Indeed, it would. It would also /prevent/ the system > > from automatically rebooting itself into a usable state ;) > > So it's not dead in the "oh, it'll be back in 30 seconds" sense. > So our behaviour is broken (more so than random process > killing). *nod* Not killing init when we "should" definately prevents embedded systems from auto-rebooting when they should do so. (OTOH, I don't think embedded systems will run into this OOM issue too much) > > > You care about getting an automatic reboot. So you need to be sure the > > > watchdog daemon gets killed first or you panic() after some time. > > > > echo 30 > /proc/sys/kernel/panic > > that's what I said. we need to be sure to _get_ a panic() though. I believe the kernel automatically panic()s when init dies ... from kernel/exit.c::do_exit() if (tsk->pid == 1) panic("Attempted to kill init!"); [which will make our system auto-reboot and be back on its feet in a healty state again soon] 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/