Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932428AbVKGMUT (ORCPT ); Mon, 7 Nov 2005 07:20:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932337AbVKGMUS (ORCPT ); Mon, 7 Nov 2005 07:20:18 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:53421 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S932428AbVKGMUR (ORCPT ); Mon, 7 Nov 2005 07:20:17 -0500 Date: Mon, 7 Nov 2005 13:20:09 +0100 From: Ingo Molnar To: Dave Hansen Cc: Linus Torvalds , Kyle Moffett , Paul Jackson , andy@thermo.lanl.gov, mbligh@mbligh.org, Andrew Morton , arjan@infradead.org, arjanv@infradead.org, kravetz@us.ibm.com, lhms , Linux Kernel Mailing List , linux-mm , mel@csn.ul.ie, Nick Piggin Subject: Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 Message-ID: <20051107122009.GD3609@elte.hu> References: <20051104010021.4180A184531@thermo.lanl.gov> <20051103221037.33ae0f53.pj@sgi.com> <20051104063820.GA19505@elte.hu> <796B585C-CB1C-4EBA-9EF4-C11996BC9C8B@mac.com> <20051107080042.GA29961@elte.hu> <1131361258.5976.53.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1131361258.5976.53.camel@localhost> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=disabled SpamAssassin version=3.0.4 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1240 Lines: 28 * Dave Hansen wrote: > On Mon, 2005-11-07 at 09:00 +0100, Ingo Molnar wrote: > > * Linus Torvalds wrote: > > > So remappable kernels are certainly doable, they just have more > > > fundamental problems than remappable user space _ever_ has. Both from > > > a performance and from a complexity angle. > > > > furthermore, it doesnt bring us any closer to removable RAM. The problem > > is still unsolvable (due to the 'how to do you find live pointers to fix > > up' issue), even if the full kernel VM is 'mapped' at 4K granularity. > > I'm not sure I understand. If you're remapping, why do you have to > find live and fix up live pointers? Are you talking about things that > require fixed _physical_ addresses? RAM removal, not RAM replacement. I explained all the variants in an earlier email in this thread. "extending RAM" is relatively easy. "replacing RAM" while doable, is probably undesirable. "removing RAM" impossible. Ingo - 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/