Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932694AbWAJVP1 (ORCPT ); Tue, 10 Jan 2006 16:15:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932315AbWAJVP1 (ORCPT ); Tue, 10 Jan 2006 16:15:27 -0500 Received: from master.soleranetworks.com ([67.137.28.188]:5528 "EHLO master.soleranetworks.com") by vger.kernel.org with ESMTP id S932694AbWAJVP0 (ORCPT ); Tue, 10 Jan 2006 16:15:26 -0500 Message-ID: <43C40B63.9090609@wolfmountaingroup.com> Date: Tue, 10 Jan 2006 12:30:43 -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: Jens Axboe Cc: Alan Cox , Linus Torvalds , Martin Bligh , Byron Stanoszek , Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: 2G memory split References: <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> <43C40738.4070600@wolfmountaingroup.com> <20060110210237.GL3389@suse.de> In-Reply-To: <20060110210237.GL3389@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1806 Lines: 62 Jens Axboe wrote: >On Tue, Jan 10 2006, Jeff V. Merkey wrote: > > >>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. >> >> > >You can't compare the two patches, saying that 4:4 should go in because >configurable page offsets is merged is nonsense. > >Note that I'm not advocating against 4:4 as such, I have no real >oppinion on that. It has its uses for sure, while it comes with a cost >for others. > > > I agree and I appreciate your recognizing this. As it stands, if I need 4:4 I just ship on ES3 and ES4. the 3:1 patch in the standard kernel is a very good thing, and you are to be commended for finally getting it in. P.S. Your bio stuff works great. Jeff - 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/