Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932628AbWAJU5o (ORCPT ); Tue, 10 Jan 2006 15:57:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932629AbWAJU5o (ORCPT ); Tue, 10 Jan 2006 15:57:44 -0500 Received: from master.soleranetworks.com ([67.137.28.188]:3224 "EHLO master.soleranetworks.com") by vger.kernel.org with ESMTP id S932628AbWAJU5j (ORCPT ); Tue, 10 Jan 2006 15:57:39 -0500 Message-ID: <43C40738.4070600@wolfmountaingroup.com> Date: Tue, 10 Jan 2006 12:12:56 -0700 From: "Jeff V. Merkey" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox Cc: Linus Torvalds , Martin Bligh , Jens Axboe , Byron Stanoszek , Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: 2G memory split References: <20060110125852.GA3389@suse.de> <20060110132957.GA28666@elte.hu> <20060110133728.GB3389@suse.de> <20060110143931.GM3389@suse.de> <43C3F986.4090209@mbligh.org> <43C3E74D.7060309@wolfmountaingroup.com> <1136926519.14532.46.camel@localhost.localdomain> In-Reply-To: <1136926519.14532.46.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1138 Lines: 44 Alan Cox wrote: >On Maw, 2006-01-10 at 09:56 -0700, Jeff V. Merkey wrote: > > >>RH ES uses 4:4 which is ideal and superior to this hack. >> >> > >Its a non trivial trade-off. 4/4 lets you run very large physical memory >systems much more efficiently than usual but you pay a cost on syscalls >and some other events when using the majority of processors. The 4/4 >tricks also give most emulations (eg Qemu) serious heartburn trying to >emulate %cr3 reloading via mmap and other interfaces with high overhead >in relative terms. > >Of course AMD64 kind of shot the problem in the head once and for all. > > > Yep, they sure did. Seriously, the 4:4 option should also be present along with 3:1 and 2:2 splits. You should merge your RH work into this patch and allow both. It would save me one less patch to maintain off the tree. Alan, you're the man. :-) Jeff >Alan > > > > - 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/