Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 18 Nov 2001 16:26:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 18 Nov 2001 16:26:04 -0500 Received: from mauve.csi.cam.ac.uk ([131.111.8.38]:64473 "EHLO mauve.csi.cam.ac.uk") by vger.kernel.org with ESMTP id ; Sun, 18 Nov 2001 16:25:49 -0500 Content-Type: text/plain; charset=US-ASCII From: James A Sutherland To: war , linux-kernel@vger.kernel.org Subject: Re: Swap Date: Sun, 18 Nov 2001 21:25:50 +0000 X-Mailer: KMail [version 1.3.1] In-Reply-To: <3BF82443.5D3E2E11@starband.net> In-Reply-To: <3BF82443.5D3E2E11@starband.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 18 November 2001 9:12 pm, war wrote: > It is amazing that I could run all of that stuff, because: > > When I have swap on, and if I run all of those programs, 200-400MB of > swap is used. Yep. There's a reason for that: the kernel is *ALWAYS* able to swap pages out to disk - even without "swap space". Disabling swapspace simply forces the kernel to swap out more code, since it cannot swap out any data. (This is why you can still get "disk thrashing" without any swap - in fact, it's more likely in this case than it is with some swap added - you are just forcing your binaries to take more of the swapping load instead.) So: with swapspace, the kernel swaps out a few hundred Mb of unused data, to make room for more code. Without it, the kernel is forced to swap out code pages instead. The big news here is...? James. - 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/