Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754650AbYHGXN1 (ORCPT ); Thu, 7 Aug 2008 19:13:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752092AbYHGXNT (ORCPT ); Thu, 7 Aug 2008 19:13:19 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53986 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901AbYHGXNT (ORCPT ); Thu, 7 Aug 2008 19:13:19 -0400 Message-ID: <489B8163.3070300@kernel.org> Date: Thu, 07 Aug 2008 16:12:35 -0700 From: "H. Peter Anvin" Organization: Linux Kernel Organization, Inc. User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Linus Torvalds CC: Zachary Amsden , Alok Kataria , Ingo Molnar , the arch/x86 maintainers , LKML Subject: Re: [PATCH]Fix broken VMI in 2.6.27-rc.. References: <1218136365.23770.52.camel@alok-dev1> <489B6710.9000604@kernel.org> <1218144438.20178.336.camel@bodhitayantram.eng.vmware.com> <489B6A5C.8030400@kernel.org> <1218145344.20178.347.camel@bodhitayantram.eng.vmware.com> <489B6E83.7000202@kernel.org> <1218146154.20178.352.camel@bodhitayantram.eng.vmware.com> <489B7470.5030408@kernel.org> <489B7DFE.5010402@kernel.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1208 Lines: 29 Linus Torvalds wrote: > > On Thu, 7 Aug 2008, H. Peter Anvin wrote: >> Just moving it down by 4 MB doesn't help, since the VMI guys want as much as >> 64 MB, which is half the standard vmalloc area and hence too much address >> space lost. We can't put it at the bottom of the vmalloc area, since that >> boundary is not fixed, either. > > Yeah, ok. Since this is a 32-bit only issue, 64MB is actually a fair chunk > of our already limited virtual space. > >> The one remaining fixed boundary in the machine is the kernel-userspace >> boundary. Hence moving the 1:1 area up by one PDE unit and sticking the >> fixmap area in that region. > > Yeah, ok, but I'd be more nervous about the validation issues there. There > might be a lot of code that assumes that TASK_SIZE is the start of the 1:1 > area. It does sound like a good approach, it just makes me worry about the > test coverage. > Indeed. Unfortunately I don't see any other options. -hpa -- 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/