Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 26 Mar 2001 17:09:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 26 Mar 2001 17:08:49 -0500 Received: from zooty.lancs.ac.uk ([148.88.16.231]:32701 "EHLO zooty.lancs.ac.uk") by vger.kernel.org with ESMTP id ; Mon, 26 Mar 2001 17:08:36 -0500 Message-Id: In-Reply-To: In-Reply-To: Jonathan Morton's message of "Sun, 25 Mar 2001 17:36:21 +0100" <3ABDF8A6.7580BD7D@evision-ventures.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 26 Mar 2001 23:00:42 +0100 To: buhr@stat.wisc.edu (Kevin Buhr) From: Jonathan Morton Subject: Re: [PATCH] OOM handling Cc: Martin Dalecki , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> Understood - my Physics courses covered this as well, but not using the >> word "normalise". > >Be that as it may, Martin's comments about normalizing are nonsense. >Rik's killer (at least in 2.4.3-pre7) produces a badness value that's >a product of badness factors of various units. It then uses these >products only for relative comparisons, choosing the process with >maximum badness product to kill. No normalization is necessary, nor >would it have any effect. > >The reason a 256 Meg process on a 1 Gig machine was being killed had >nothing to do with normalization---it was a bug where the OOM killer >was being called long before we were reduced to last resorts. Of course, I realised that. Actually, what the code does is take an initial badness factor (the memory usage), then divide it using goodness factors (some based on time, some purely arbitrary), both of which can be considered dimensionless. Also, at the end, the absolute value is not considered - we simply look at the biggest one and kill it. All "denormalisation" does is scale all the values, it doesn't affect which one actually turns out biggest. -------------------------------------------------------------- from: Jonathan "Chromatix" Morton mail: chromi@cyberspace.org (not for attachments) big-mail: chromatix@penguinpowered.com uni-mail: j.d.morton@lancaster.ac.uk The key to knowledge is not to rely on people to teach you it. Get VNC Server for Macintosh from http://www.chromatix.uklinux.net/vnc/ -----BEGIN GEEK CODE BLOCK----- Version 3.12 GCS$/E/S dpu(!) s:- a20 C+++ UL++ P L+++ E W+ N- o? K? w--- O-- M++$ V? PS PE- Y+ PGP++ t- 5- X- R !tv b++ DI+++ D G e+ h+ r++ y+(*) -----END GEEK CODE BLOCK----- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/