From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759421AbZELPvk (ORCPT ); Tue, 12 May 2009 11:51:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751881AbZELPva (ORCPT ); Tue, 12 May 2009 11:51:30 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56049 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbZELPv3 (ORCPT ); Tue, 12 May 2009 11:51:29 -0400 Message-ID: <4A099AF0.8020001@zytor.com> Date: Tue, 12 May 2009 08:51:12 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Jan Beulich CC: Ingo Molnar , Thomas Gleixner , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: uses of cmpxchg/xadd in spinlock.h and rwsem.h vs. CONFIG_M386 References: <4A09AF8402000078000007DC@vpn.id2.novell.com> In-Reply-To: <4A09AF8402000078000007DC@vpn.id2.novell.com> 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 Jan Beulich wrote: > While looking at a completely different issue I happened to grep for uses of > xadd, and it would appear to me that there got uses added that would make > a M386-configured SMP kernel die on an actual i386. > > Oh, for the rwsem case I see - it would use the RWSEM_GENERIC_SPINLOCK case > when selecting M386. But I see nothing similar for the ticket spinlocks - am > I overlooking something? It's quite possible we break 386 on a regular basis... I'm not sure how many people even in the embedded industry run current kernels on 386-compatible hardware. Most embedded hardware is at least 486. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.