From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from atlrel9.hp.com (atlrel9.hp.com [156.153.255.214]) by dsl2.external.hp.com (Postfix) with ESMTP id 3A0F34840 for ; Tue, 30 Sep 2003 06:25:01 -0600 (MDT) Message-ID: <3F7975FE.58C276D9@india.hp.com> Date: Tue, 30 Sep 2003 17:54:30 +0530 From: Naresh Reply-To: knaresh@india.hp.com MIME-Version: 1.0 To: Matthew Wilcox Cc: parisc-linux@lists.parisc-linux.org Subject: Re: [parisc-linux] MAX_ADDRESS. References: <3F7915A7.1F54379@india.hp.com> <20030930120636.GV24824@parcelfarce.linux.theplanet.co.uk> Content-Type: text/plain; charset=us-ascii Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: MAX_ADDRESS has nothing to do with DISCONTIGMEM. Its definition is generic( pgtable.h), although it is not used anywhere. I just happened to see the comment in the DISCONTIGMEM code. Even if DISCONTIGMEM is turned off, there is no check for MAX_ADDRESS before the call to 'map_pages()' in 'pagetable_init( )', which is why I would like to know if MAX_ADDRESS can be ignored. Regards, Naresh. Matthew Wilcox wrote: > On Tue, Sep 30, 2003 at 11:03:28AM +0530, Naresh wrote: > > This question is relevant to the 2.4 kernel. Is MAX_ADDRESS really the > > highest virtual address mapped by the kernel? I can see this comment in > > 'paging_init()' in the section for DISCONTIGMEM. However, > > pagetable_init() doesnt make a check before it calls 'map_pages( )' for > > all the ranges of memory. So we may DISCONTIGMEM turned off but it may > > so happen that we have a 'pmem_ranges[]' entry that is greater than > > MAX_ADDRESS which may find its way into the kernel page tables. > > Ignore the DISCONTIGMEM code. It's completely broken (and we offer no > way to turn CONFIG_DISCONTIGMEM on). > > I'm not sure what half of this code is for; you'd need to ask John Marvin > who wrote it. > > -- > "It's not Hollywood. War is real, war is primarily not about defeat or > victory, it is about death. I've seen thousands and thousands of dead bodies. > Do you think I want to have an academic debate on this subject?" -- Robert Fisk > _______________________________________________ > parisc-linux mailing list > parisc-linux@lists.parisc-linux.org > http://lists.parisc-linux.org/mailman/listinfo/parisc-linux