From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760257Ab0HLPfd (ORCPT ); Thu, 12 Aug 2010 11:35:33 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33614 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760169Ab0HLPfb (ORCPT ); Thu, 12 Aug 2010 11:35:31 -0400 Message-ID: <4C64148D.5080305@zytor.com> Date: Thu, 12 Aug 2010 08:34:37 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.7) Gecko/20100720 Fedora/3.1.1-1.fc13 Thunderbird/3.1.1 MIME-Version: 1.0 To: Joerg Roedel CC: "Roedel, Joerg" , Borislav Petkov , "mingo@elte.hu" , "tglx@linutronix.de" , "Herrmann3, Andreas" , "Seidel, Conny" , "Sarathy, Bhavna" , "greg@kroah.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/2] x86-32: Fix crashes with CPU hotplug on AMD machines References: <1280940316-7966-1-git-send-email-bp@amd64.org> <1280940316-7966-2-git-send-email-bp@amd64.org> <4C59F24B.1010702@zytor.com> <20100805074503.GI18307@amd.com> <4C5AC736.20903@zytor.com> <20100812144142.GY23755@8bytes.org> In-Reply-To: <20100812144142.GY23755@8bytes.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/12/2010 07:41 AM, Joerg Roedel wrote: > On Thu, Aug 05, 2010 at 07:14:14AM -0700, H. Peter Anvin wrote: >> On 08/05/2010 12:45 AM, Roedel, Joerg wrote: >> Correct, again. It's unclear to me if we can get away with the very >> simple 64-bit approach -- in particular, not including all the 1:1 >> mappings in the kernel -- for all future users, though. > > Yeah, We could probably use the same symbol names for the trampoline and > the swapper page-table on 32 and 64 bit and merge the code that handles > it between the architectures. Shouldn't be too difficult. We cook > something up :-) > But do you mind to take this patch first? It fixes the occurence of an > erratum on AMD hardware, it is a quite simple fix compared to the rework > suggested. In fact, I would like to have a simple patch to fix the > problem first (and backport it as necessary) and then go the way to > rework the current code differences between 32 and 64 bit. > Agreed. I do have a concern about the kernel page tables not being synchronized into trampoline_pg_dir (it's only an issue for 32-bit !PAE), so at the very least we need to keep an eye out for it... -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.