Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753251AbWKLVr0 (ORCPT ); Sun, 12 Nov 2006 16:47:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753255AbWKLVrZ (ORCPT ); Sun, 12 Nov 2006 16:47:25 -0500 Received: from mx1.redhat.com ([66.187.233.31]:4739 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1753251AbWKLVrY (ORCPT ); Sun, 12 Nov 2006 16:47:24 -0500 Date: Sun, 12 Nov 2006 16:45:40 -0500 From: Dave Jones To: Arjan van de Ven Cc: Adrian Bunk , Andrew Morton , David Howells , Neil Brown , "bugme-daemon@kernel-bugs.osdl.org" , linux-kernel@vger.kernel.org, alex@hausnet.ru, mingo@redhat.com, ak@suse.de Subject: Re: [Bugme-new] [Bug 7495] New: Kernel periodically hangs. Message-ID: <20061112214540.GB31649@redhat.com> Mail-Followup-To: Dave Jones , Arjan van de Ven , Adrian Bunk , Andrew Morton , David Howells , Neil Brown , "bugme-daemon@kernel-bugs.osdl.org" , linux-kernel@vger.kernel.org, alex@hausnet.ru, mingo@redhat.com, ak@suse.de References: <20061111100038.6277efd4.akpm@osdl.org> <1163268603.3293.45.camel@laptopd505.fenrus.org> <20061111101942.5f3f2537.akpm@osdl.org> <1163332237.3293.100.camel@laptopd505.fenrus.org> <20061112125357.GH25057@stusta.de> <1163337376.3293.120.camel@laptopd505.fenrus.org> <20061112133759.GK25057@stusta.de> <1163339868.3293.126.camel@laptopd505.fenrus.org> <20061112141016.GA5297@stusta.de> <1163340998.3293.131.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1163340998.3293.131.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1328 Lines: 30 On Sun, Nov 12, 2006 at 03:16:38PM +0100, Arjan van de Ven wrote: > > > > We KNOW it can't work on a sizable amount of machines. This is why it > > > is a config option; you can enable it if YOUR machine is KNOWN to work, > > > and you get some gains. But it's also understood that it often it won't > > > work. So any sensible distro (since they have to aim for a wide > > > audience) disables this option ... > > > > Nowadays, many distributions only ship CONFIG_SMP=y kernels... > > that's a calculated risk on their side (and they know that); they're > balancing not functioning on a set of machines off against needing more > kernels. Andi has a nice patch in the suse kernel which adds heuristics to disable apic on systems where it isn't likely to work. It DTRT in at least one problem case that I know of. The actual fall-out from enabling 'run SMP kernels on UP i686' for FC6 has mostly been a non-event. Literally a handful of cases, that will likely all get caught and worked around by Andi's patch or similar. Dave -- http://www.codemonkey.org.uk - 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/