From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265506AbUBPKZG (ORCPT ); Mon, 16 Feb 2004 05:25:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265513AbUBPKZG (ORCPT ); Mon, 16 Feb 2004 05:25:06 -0500 Received: from aun.it.uu.se ([130.238.12.36]:35544 "EHLO aun.it.uu.se") by vger.kernel.org with ESMTP id S265506AbUBPKZA (ORCPT ); Mon, 16 Feb 2004 05:25:00 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16432.39480.817800.21083@alkaid.it.uu.se> Date: Mon, 16 Feb 2004 11:23:52 +0100 From: Mikael Pettersson To: Philippe Elie Cc: Andrew Morton , linux-kernel@vger.kernel.org, Will Cohen , John Levon Subject: Re: [PATCH] oprofile add Pentium Mobile support In-Reply-To: <20040212224152.GE316@zaniah> References: <20040212224152.GE316@zaniah> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Philippe Elie writes: > From: Will Cohen > > Add oprofile support for Pentium Mobile (P6 core). Pentium Mobile needs > to unmask LVPTC vector, since it doesn't hurt other P6 core based cpus > we do it unconditionally for all these. [Patch talking about the Pentium-M.] I can find no support in Intel's documentation (IA32 Volume 3, 25366813.pdf) that Pentium-M:s need to unmask LVTPC. How certain are you of this? Is this an undocumented hardware quirk? If it is documented, please indicate where. It's my theory that P4 added the auto-masking to help PEBS buffer overflow situations, but since P-M doesn't have PEBS, they shouldn't have had to change this on P-M as well. OTOH, it's certainly possible they changed it by accident. One way of testing this would be to run a P-M with nmi_watchdog=2. If the NMI counter keeps ticking, then LVTPC does not need unmasking. /Mikael