From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932187AbWAJSp7 (ORCPT ); Tue, 10 Jan 2006 13:45:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932237AbWAJSp7 (ORCPT ); Tue, 10 Jan 2006 13:45:59 -0500 Received: from master.soleranetworks.com ([67.137.28.188]:26007 "EHLO master.soleranetworks.com") by vger.kernel.org with ESMTP id S932187AbWAJSp6 (ORCPT ); Tue, 10 Jan 2006 13:45:58 -0500 Message-ID: <43C3E85B.5000902@wolfmountaingroup.com> Date: Tue, 10 Jan 2006 10:01:15 -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: "Jeff V. Merkey" 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> In-Reply-To: <43C3E74D.7060309@wolfmountaingroup.com> 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 Jeff V. Merkey wrote: > Linus Torvalds wrote: > >> On Tue, 10 Jan 2006, Martin Bligh wrote: >> >> >>> The non-1GB-aligned ones need to be disbarred when PAE is on, I think. >>> >> >> Well, right now _all_ the non-3:1 cases need to be disbarred. I think >> we depend on the kernel mapping only ever being the _one_ last entry >> in the top-level page table, which is only true with the 3:1 mapping. >> >> But I didn't check. >> >> > > > No. It works fine (or seems to) with 2:2 mapping. I've tested with > these extensively > and am shipping products on the 1U appliances with 2:2 and I have > never seen any problems > with 2.6.9-2.6.13. > > The only unpleasant side affect with 3:1 is user apps seem to rely on > swap space > a little more than I like -- perhaps this is the side affect you are > referring to? > > RH ES uses 4:4 which is ideal and superior to this hack. > > Jeff > Take that back. I checked the build and 2:2 does not work correctly with highmem enabled. So you may be correct. Highmem support is crap anyway and a 4:4 scheme is what this should have been from the start. It's ok. The nice thing about Linux if you don't like what Linus is cooking in the kitchen, you can add your own ingredients and make something else. Jeff