Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 13 Oct 2001 14:37:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 13 Oct 2001 14:36:57 -0400 Received: from mail3.aracnet.com ([216.99.193.38]:27909 "EHLO mail3.aracnet.com") by vger.kernel.org with ESMTP id ; Sat, 13 Oct 2001 14:36:53 -0400 From: "M. Edward Borasky" To: Subject: RE: Which is better at vm, and why? 2.2 or 2.4 Date: Sat, 13 Oct 2001 11:37:22 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-Reply-To: <20011013141709.L249@localhost> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: linux-kernel-owner@vger.kernel.org > [mailto:linux-kernel-owner@vger.kernel.org]On Behalf Of Patrick > McFarland > Sent: Saturday, October 13, 2001 11:17 AM > To: M. Edward Borasky > Cc: linux-kernel@vger.kernel.org > Subject: Re: Which is better at vm, and why? 2.2 or 2.4 > > > Hmm, I see that as very bad. There should be a bunch of sysctls > to do that easily. Also, I heard that 2.4 (and I'm assuming 2.2 > as well) swaps pages on a last-used-age basis, instead of either > a number-of-times-used or a hybrid of the two. That kinda seems > stupid, especially if you get a bunch of apps running that just > cycle thru pages, instead of the most used pages staying in > memory, and the least used being swapped back and forth with > about 2 or 3 megs of memory used to store the least used pages in memory What do you see as bad? The ability to change tuning parameters on the fly or the lack of such ability? At the very least, I need to be able to poke settings with a debugger, and a more systematic and user-friendly interface would be preferable. Your example is exactly what I'm talking about! Neither the applications nor the kernel are "stupid"; they are doing exactly what they're being paid to do. My job as a system tuner is to make sure that the users get the response times and throughputs they need, given the inherent limits of how much they can afford to pay for processors, memory and disk. As an aside, I also need to be able to figure out what those limits are -- when it's time to add capacity rather than just tune the system. -- M. Edward (Ed) Borasky, Chief Scientist, Borasky Research http://www.borasky-research.net mailto:znmeb@borasky-research.net http://groups.yahoo.com/group/BoraskyResearchJournal Q: How do you tell when a pineapple is ready to eat? A: It picks up its knife and fork. - 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/