Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423801AbWKPU3l (ORCPT ); Thu, 16 Nov 2006 15:29:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424467AbWKPU3l (ORCPT ); Thu, 16 Nov 2006 15:29:41 -0500 Received: from smtp.osdl.org ([65.172.181.4]:60077 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1423801AbWKPU3j (ORCPT ); Thu, 16 Nov 2006 15:29:39 -0500 Date: Thu, 16 Nov 2006 12:23:58 -0800 From: Andrew Morton To: Mikael Pettersson Cc: ebiederm@xmission.com (Eric W. Biederman), Andi Kleen , Linus Torvalds , discuss@x86-64.org, William Cohen , 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 , Andrey Borzenkov Subject: Re: [discuss] Re: 2.6.19-rc5: known regressions (v3) Message-Id: <20061116122358.996fdbb3.akpm@osdl.org> In-Reply-To: <17756.17330.974883.486535@alkaid.it.uu.se> References: <200611151945.31535.ak@suse.de> <200611152023.53960.ak@suse.de> <20061115122118.14fa2177.akpm@osdl.org> <20061115133121.8d9d621f.akpm@osdl.org> <17756.17330.974883.486535@alkaid.it.uu.se> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1028 Lines: 23 On Thu, 16 Nov 2006 11:55:46 +0100 Mikael Pettersson wrote: > Andrew Morton writes: > > Surely the appropriate behaviour is to allow oprofile to steal the NMI and > > to then put the NMI back to doing the watchdog thing after oprofile has > > finished with it. > > Which is _exactly_ what pre-2.6.19-rc1 kernels did. I implemented > the in-kernel API allowing real performance counter drivers like > oprofile (and perfctr) to claim the HW from the NMI watchdog, > do their work, and then release it which resumed the watchdog. OK. But from Andi's comments it seems that the NMI watchdog was failing to resume its operation. > Note that oprofile (and perfctr) didn't do anything behind the > NMI watchdog's back. They went via the API. Nothing dodgy going on. - 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/