From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 8 Dec 2001 20:09:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 8 Dec 2001 20:09:37 -0500 Received: from web10001.mail.yahoo.com ([216.136.130.37]:16472 "HELO web10001.mail.yahoo.com") by vger.kernel.org with SMTP id ; Sat, 8 Dec 2001 20:09:34 -0500 Message-ID: <20011209010933.64484.qmail@web10001.mail.yahoo.com> Date: Sun, 9 Dec 2001 01:09:33 +0000 (GMT) From: "=?iso-8859-1?q?Quim=20K.=20Holland?=" Subject: Required Swap for recent 2.4 kernels? To: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org It seems that in early days of 2.4.x, the total usable VM used to be not close to sum of the physical RAM and swap. Is this still true for post 2.4.10 kernels? Back in January 2001, in response to a question about ``recommended swap for 2.4.x'', Rik van Riel answered (quotes '>' are from the messagey by alex@foogod.com): It has. We now leave dirty pages swapcached, which means that for certain workloads Linux 2.4 eats up much more swap space than Linux 2.2. On the other hand, if you almost never used swap under Linux 2.2, you probably won't be using it under 2.4 either. > 2) Subtract the amount of RAM you have > (believe it or not, the more RAM you have, > the less swap you need. Imagine that). For Linux 2.4, it may be better to substract a bit less, because of the issue above. If you have a very swap-intensive workload, you may end up with 90% of your memory being "duplicated" in swap, in which case this rule doesn't work. My understanding is that this answer is not applicable to post 2.4.10 kernels, but if so then would the total usable VM be + - - ? ________________________________________________________________ Nokia 5510 looks weird sounds great. Go to http://uk.promotions.yahoo.com/nokia/ discover and win it! The competition ends 16 th of December 2001.