From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 20 Sep 2001 08:52:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 20 Sep 2001 08:52:22 -0400 Received: from lightning.swansea.linux.org.uk ([194.168.151.1]:23562 "EHLO the-village.bc.nu") by vger.kernel.org with ESMTP id ; Thu, 20 Sep 2001 08:52:17 -0400 Subject: Re: broken VM in 2.4.10-pre9 To: phillips@bonn-fries.net (Daniel Phillips) Date: Thu, 20 Sep 2001 13:57:02 +0100 (BST) Cc: alan@lxorguk.ukuu.org.uk (Alan Cox), ebiederm@xmission.com (Eric W. Biederman), rfuller@nsisoftware.com (Rob Fuller), linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <20010920112110Z16256-2757+869@humbolt.nl.linux.org> from "Daniel Phillips" at Sep 20, 2001 01:28:31 PM X-Mailer: ELM [version 2.5 PL6] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > On September 20, 2001 12:04 am, Alan Cox wrote: > > Reverse mappings make linear aging easier to do but are not critical (we > > can walk all physical pages via the page map array). > > But you can't pick up the referenced bit that way, so no up aging, only > down. #1 If you really wanted to you could update a referenced bit in the page struct in the fault handling path. #2 If a page is referenced multiple times by different processes is the behaviour of multiple upward aging actually wrong. Alan