Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759845AbXF3OpG (ORCPT ); Sat, 30 Jun 2007 10:45:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756226AbXF3Oon (ORCPT ); Sat, 30 Jun 2007 10:44:43 -0400 Received: from rgminet01.oracle.com ([148.87.113.118]:24115 "EHLO rgminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756854AbXF3Oom (ORCPT ); Sat, 30 Jun 2007 10:44:42 -0400 Message-ID: <46866C58.2090705@oracle.com> Date: Sat, 30 Jun 2007 07:44:40 -0700 From: Randy Dunlap User-Agent: Thunderbird 1.5.0.5 (X11/20060719) MIME-Version: 1.0 To: John Keller CC: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, steiner@sgi.com Subject: Re: [PATCH] - x86_64-add-ioapic-nmi-support-fix-3 References: <200706301429.l5UETMXk295940@fcbayern.americas.sgi.com> In-Reply-To: <200706301429.l5UETMXk295940@fcbayern.americas.sgi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 49 John Keller wrote: >> [adding Andi Kleen] >> >> John Keller wrote: >>> Place all the IOACPI NMI support code under CONFIG_ACPI >>> to clear up build errors with certain configs. >>> >>> Signed-off-by: John Keller >>> --- >> Is there some architectural reason that IO APIC NMI support should >> require ACPI? > > OK, I guess standing alone this description was a bit misleading. > The code referred to here is the new code supporting the ACPI NMI SRC > structure that can be specified in the MADT. Without ACPI support this > code is not relevant. All the code touched by this patch was introduced > by eariler versions of this patchset. > > This patch makes no changes to the workings of nmi_watchdog. OK, thanks for the clarification. > John > > >> Is this a new requirement? It seems like a step backwards to me. >> >> >> Documentation/nmi_watchdog.txt doesn't say anything about ACPI being >> needed. It does say: >> >> "For x86-64, the needed APIC is always compiled in, and the NMI watchdog is >> always enabled with I/O-APIC mode (nmi_watchdog=1). Currently, local APIC >> mode (nmi_watchdog=2) does not work on x86-64. >> >> Using local APIC (nmi_watchdog=2) needs the first performance register, so >> you can't use it for other purposes (such as high precision performance >> profiling.) However, at least oprofile and the perfctr driver disable the >> local APIC NMI watchdog automatically." -- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** - 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/