From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752349AbZIIBCt (ORCPT ); Tue, 8 Sep 2009 21:02:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750778AbZIIBCt (ORCPT ); Tue, 8 Sep 2009 21:02:49 -0400 Received: from terminus.zytor.com ([198.137.202.10]:44776 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750751AbZIIBCs (ORCPT ); Tue, 8 Sep 2009 21:02:48 -0400 Message-ID: <4AA6FE42.9070700@zytor.com> Date: Tue, 08 Sep 2009 18:00:50 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Ben Hutchings CC: x86@kernel.org, linux-kernel@vger.kernel.org, Richard Kettlewell Subject: Re: [PATCH] x86: Fix code patching for paravirt-alternatives on 486 References: <1252452228.3423.121.camel@localhost> <4AA6F777.2080103@zytor.com> <1252457195.3423.124.camel@localhost> In-Reply-To: <1252457195.3423.124.camel@localhost> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/08/2009 05:46 PM, Ben Hutchings wrote: > On Tue, 2009-09-08 at 17:31 -0700, H. Peter Anvin wrote: > [...] >> I'm wondering if it wouldn't be cleaner to fold the jump into >> sync_core() and moving the sync_core() up before local_irq_restore(). > > Exactly as I suggested below the dashes. :-) > Ah, yes, so you did indeed. > The only reason I didn't do that initially was that I don't know whether > or not there's a good reason for the current placement of sync_core() > after local_irq_restore(). I can personally not fathom how moving the sync_core() before local_irq_restore() could cause problems -- in fact, the current code seems logically wrong, although probably correct in practice, as the interrupt itself should perform the necessary synchronization (although it is not architecturally required to do so.) Not that I haven't been wrong before. -hpa