From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 7 Nov 2005 13:20:09 +0100 From: Ingo Molnar 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> Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: * 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org