Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031039AbWKPDVj (ORCPT ); Wed, 15 Nov 2006 22:21:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031048AbWKPDVj (ORCPT ); Wed, 15 Nov 2006 22:21:39 -0500 Received: from ns2.suse.de ([195.135.220.15]:21702 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1031039AbWKPDVi (ORCPT ); Wed, 15 Nov 2006 22:21:38 -0500 Date: Thu, 16 Nov 2006 04:21:09 +0100 From: Andi Kleen To: Andrew Morton Cc: Andi Kleen , Linus Torvalds , discuss@x86-64.org, William Cohen , Eric Dumazet , Komuro , Ernst Herzberg , Andre Noll , oprofile-list@lists.sourceforge.net, Jens Axboe , linux-usb-devel@lists.sourceforge.net, phil.el@wanadoo.fr, Adrian Bunk , Ingo Molnar , Alan Stern , linux-pci@atrey.karlin.mff.cuni.cz, Stephen Hemminger , Prakash Punnoor , Len Brown , Alex Romosan , gregkh@suse.de, Linux Kernel Mailing List , "Eric W. Biederman" , Andrey Borzenkov Subject: Re: [discuss] Re: 2.6.19-rc5: known regressions (v3) Message-ID: <20061116032109.GG9579@bingen.suse.de> References: <200611151945.31535.ak@suse.de> <200611152023.53960.ak@suse.de> <20061115122118.14fa2177.akpm@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061115122118.14fa2177.akpm@osdl.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2017 Lines: 65 On Wed, Nov 15, 2006 at 12:21:18PM -0800, Andrew Morton wrote: > Andi Kleen wrote: > > > > > > The fact is, it used to work, and the kernel changed interfaces, so now it > > > doesn't. > > > > No, it didn't work. oprofile may have done something, but it > > just silently killed the NMI watchdog in the process. > > That was never acceptable. > > But people could get profiles out. I know, I've seen them! Just the nmi watchdog was gone then. > > > Now we do proper accounting of NMI sources and also proper allocation > > of performance counters. > > > > > > > Yes, "oprofile" should be fixed to not depend on that, but the kernel > > > shouldn't change the interfaces, and we should add back the zero entry. > > > > That would break the nmi watchdog again. > > > > Anyways, there is a sysctl to disable the nmi watchdog if someone > > is desperate. > > > > But I think it is clearly oprofile who did wrong here and needs > > to be fixed. > > > > Is it correct to say that oprofile-on-2.6.18 works, and that > oprofile-on-2.6.19-rc5 does not? > > Or is there some sort of workaround for this, or does 2.6.19-rc5 only fail echo 0 > /proc/sys/kernel/nmi_watchdog before the oprofile module is loaded. With builtin oprofile probably nmi_watchdog=0 > in some particular scenarios? On x86-64 and on newer i386 machines (based on DMI year) > > If it's really true that oprofile is simply busted then that's a serious > problem and we should find some way of unbusting it. If that means just > adding a dummy "0" entry which always returns zero or something like that, > then fine. That could be probably done. > But we can't just go and bust it. It just did something unbelievable broken before. I would say it busted itself. -Andi - 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/