Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750981AbWAJNpu (ORCPT ); Tue, 10 Jan 2006 08:45:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750963AbWAJNpt (ORCPT ); Tue, 10 Jan 2006 08:45:49 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:31039 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1750875AbWAJNpt (ORCPT ); Tue, 10 Jan 2006 08:45:49 -0500 Date: Tue, 10 Jan 2006 14:47:43 +0100 From: Jens Axboe To: Byron Stanoszek Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds Subject: Re: 2G memory split Message-ID: <20060110134742.GD3389@suse.de> References: <20060110125852.GA3389@suse.de> <20060110132957.GA28666@elte.hu> <20060110133728.GB3389@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1363 Lines: 30 On Tue, Jan 10 2006, Byron Stanoszek wrote: > On Tue, 10 Jan 2006, Jens Axboe wrote: > > >>yes, i made it totally configurable in 2.4 days: 1:3, 2/2 and 3:1 splits > >>were possible. It was a larger patch to enable all this across x86, but > >>the Kconfig portion was removed a bit later because people _frequently_ > >>misconfigured their kernels and then complained about the results. > > > >How is this different than all other sorts of misconfigurations? As far > >as I can tell, the biggest "problem" for some is if they depend on some > >binary module that will of course break with a different page offset. > > > >For simplicity, I didn't add more than the 2/2 split, where we could add > >even a 3/1 kernel/user or a 0.5/3.5 (I think sles8 had this). > > I prefer setting __PAGE_OFFSET to (0x78000000) on machines with 2GB of RAM. > This seems to let the kernel use the full 2GB of memory, rather than just > 1920-1984 MB (at least back in 2.4 days). That might indeed be a good idea for 2G/2G, in the same sense that 0xC0000000 is a silly default because of the many 1G machines out there. -- Jens Axboe - 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/