Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932453AbWAJSOc (ORCPT ); Tue, 10 Jan 2006 13:14:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932464AbWAJSOc (ORCPT ); Tue, 10 Jan 2006 13:14:32 -0500 Received: from dvhart.com ([64.146.134.43]:897 "EHLO dvhart.com") by vger.kernel.org with ESMTP id S932453AbWAJSOc (ORCPT ); Tue, 10 Jan 2006 13:14:32 -0500 Message-ID: <43C3F986.4090209@mbligh.org> Date: Tue, 10 Jan 2006 10:14:30 -0800 From: Martin Bligh User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051011) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linus Torvalds Cc: 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> In-Reply-To: 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: 1974 Lines: 61 Linus Torvalds wrote: > > On Tue, 10 Jan 2006, Jens Axboe wrote: > >>A newer version, trying to cater to the various comments in here. >>Changes: > > > Can we do one final cleanup? Do all the magic in _one_ place, namely the > x86 Kconfig file. > > Also, I don't think the NOHIGHMEM dependency is necessarily correct. A > 2G/2G split can be advantageous with a 16GB setup (you'll have more room > for dentries etc), but you obviously want to have HIGHMEM for that.. > > Do it something like this: > > choice > depends on EXPERIMENTAL > prompt "Memory split" > default DEFAULT_3G > help > Select the wanted split between kernel and user memory. > If the address range available to the kernel is less than the > physical memory installed, the remaining memory will be available > as "high memory". Accessing high memory is a little more costly > than low memory, as it needs to be mapped into the kernel first. > Note that selecting anything but the default 3G/1G split will make > your kernel incompatible with binary only modules. > > config DEFAULT_3G > bool "3G/1G user/kernel split" > config DEFAULT_3G_OPT > bool "3G/1G user/kernel split (for full 1G low memory)" > config DEFAULT_2G > bool "2G/2G user/kernel split" > config DEFAULT_1G > bool "1G/3G user/kernel split" > endchoice > > config PAGE_OFFSET > hex > default 0xC0000000 > default 0xB0000000 if DEFAULT_3G_OPT > default 0x78000000 if DEFAULT_2G > default 0x40000000 if DEFAULT_1G > > and then asm-i386/page.h can just do > > #define __PAGE_OFFSET ((unsigned long)CONFIG_PAGE_OFFSET) > > and you're done. The non-1GB-aligned ones need to be disbarred when PAE is on, I think. M. - 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/