From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755903AbZKDMdn (ORCPT ); Wed, 4 Nov 2009 07:33:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755888AbZKDMdm (ORCPT ); Wed, 4 Nov 2009 07:33:42 -0500 Received: from lennier.cc.vt.edu ([198.82.162.213]:45946 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755879AbZKDMdl (ORCPT ); Wed, 4 Nov 2009 07:33:41 -0500 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Ingo Molnar Cc: Aristeu Rozanski , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] x86: introduce NMI_AUTO as nmi_watchdog option In-Reply-To: Your message of "Wed, 04 Nov 2009 12:46:30 +0100." <20091104114630.GA16993@elte.hu> From: Valdis.Kletnieks@vt.edu References: <20091103171054.GB25437@redhat.com> <20091104114630.GA16993@elte.hu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1257337997_3003P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 04 Nov 2009 07:33:17 -0500 Message-ID: <38974.1257337997@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 128.173.34.98 turing-police.cc.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Mirapoint-IP-Reputation: reputation=neutral-1, source=Fixed, refid=n/a, actions=MAILHURDLE SPF TAG X-Junkmail-Info: (0) X-Junkmail-Status: score=10/50, host=vivi.cc.vt.edu X-Junkmail-SD-Raw: score=unknown, refid=str=0001.0A020207.4AF1748E.0289,ss=1,fgs=0, ip=0.0.0.0, so=2009-07-29 21:33:33, dmn=2009-09-10 00:05:08, mode=multiengine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1257337997_3003P Content-Type: text/plain; charset=us-ascii On Wed, 04 Nov 2009 12:46:30 +0100, Ingo Molnar said: > What i'd like to see for the NMI watchdog is much more ambitious than > this: the use of perf events to run a periodic NMI callback. > > The NMI watchdog would cause the creation of a per-cpu perf_event > structure (in-kernel). All x86 CPUs that have perf event support (the > majority of them) will thus be able to have an NMI watchdog using a > nice, generic piece of code and we'd be able to phase out the open-coded > NMI watchdog code. What happens on older/smaller x86 CPUs that don't have any native support for perf events? --==_Exmh_1257337997_3003P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFK8XSNcC3lWbTT17ARApbXAKDNn9BL4mFlbsYw3zIHrL+i/RJPWgCdGfm1 sWDJMnReC0qjlaxbjj/u2xs= =KDhg -----END PGP SIGNATURE----- --==_Exmh_1257337997_3003P--