From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 9098FC433EF for ; Thu, 14 Jun 2018 01:02:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FF19208D5 for ; Thu, 14 Jun 2018 01:02:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3FF19208D5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935996AbeFNBCm (ORCPT ); Wed, 13 Jun 2018 21:02:42 -0400 Received: from mga03.intel.com ([134.134.136.65]:4866 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935789AbeFNBCk (ORCPT ); Wed, 13 Jun 2018 21:02:40 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Jun 2018 18:02:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,220,1526367600"; d="scan'208";a="47595887" Received: from voyager.sc.intel.com (HELO voyager) ([10.3.52.149]) by fmsmga008.fm.intel.com with ESMTP; 13 Jun 2018 18:02:14 -0700 Date: Wed, 13 Jun 2018 17:58:39 -0700 From: Ricardo Neri To: Randy Dunlap Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Ashok Raj , Borislav Petkov , Tony Luck , "Ravi V. Shankar" , x86@kernel.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Jacob Pan , "Rafael J. Wysocki" , Don Zickus , Nicholas Piggin , Michael Ellerman , Frederic Weisbecker , Alexei Starovoitov , Babu Moger , Mathieu Desnoyers , Masami Hiramatsu , Peter Zijlstra , Andrew Morton , Philippe Ombredanne , Colin Ian King , Byungchul Park , "Paul E. McKenney" , "Luis R. Rodriguez" , Waiman Long , Josh Poimboeuf , Davidlohr Bueso , Christoffer Dall , Marc Zyngier , Kai-Heng Feng , Konrad Rzeszutek Wilk , David Rientjes , iommu@lists.linux-foundation.org Subject: Re: [RFC PATCH 22/23] watchdog/hardlockup/hpet: Only enable the HPET watchdog via a boot parameter Message-ID: <20180614005839.GA22358@voyager> References: <1528851463-21140-1-git-send-email-ricardo.neri-calderon@linux.intel.com> <1528851463-21140-23-git-send-email-ricardo.neri-calderon@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 12, 2018 at 10:26:57PM -0700, Randy Dunlap wrote: > On 06/12/2018 05:57 PM, Ricardo Neri wrote: > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index f2040d4..a8833c7 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2577,7 +2577,7 @@ > > Format: [state][,regs][,debounce][,die] > > > > nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels > > - Format: [panic,][nopanic,][num] > > + Format: [panic,][nopanic,][num,][hpet] > > Valid num: 0 or 1 > > 0 - turn hardlockup detector in nmi_watchdog off > > 1 - turn hardlockup detector in nmi_watchdog on > > This says that I can use "nmi_watchdog=hpet" without using 0 or 1. > Is that correct? Yes, this what I meant. In my view, if you set nmi_watchdog=hpet it implies that you want to activate the NMI watchdog. In this case, perf. I can see how this will be ambiguous for the case of perf and arch NMI watchdogs. Alternative, a new parameter could be added; such as nmi_watchdog_type. I didn't want to add it in this patchset as I think that a single parameter can handle the enablement and type of the NMI watchdog. What do you think? Thanks and BR, Ricardo