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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48254C282DD for ; Fri, 24 May 2019 01:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE053217F9 for ; Fri, 24 May 2019 01:17:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389168AbfEXBR6 (ORCPT ); Thu, 23 May 2019 21:17:58 -0400 Received: from mga07.intel.com ([134.134.136.100]:15050 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387626AbfEXBQi (ORCPT ); Thu, 23 May 2019 21:16:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 May 2019 18:16:36 -0700 X-ExtLoop1: 1 Received: from unknown (HELO luv-build.sc.intel.com) ([172.25.110.25]) by fmsmga008.fm.intel.com with ESMTP; 23 May 2019 18:16:36 -0700 From: Ricardo Neri To: Thomas Gleixner , Ingo Molnar , Borislav Petkov Cc: Ashok Raj , Joerg Roedel , Andi Kleen , Peter Zijlstra , Suravee Suthikulpanit , Stephane Eranian , "Ravi V. Shankar" , Randy Dunlap , x86@kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Ricardo Neri , Ricardo Neri , "H. Peter Anvin" , Tony Luck , "Rafael J. Wysocki" , Don Zickus , Nicholas Piggin , Michael Ellerman , Frederic Weisbecker , Alexei Starovoitov , Babu Moger , "David S. Miller" , Benjamin Herrenschmidt , Paul Mackerras , Mathieu Desnoyers , Masami Hiramatsu , Andrew Morton , Philippe Ombredanne , Colin Ian King , Byungchul Park , "Paul E. McKenney" , "Luis R. Rodriguez" , Waiman Long , Josh Poimboeuf , Davidlohr Bueso , Marc Zyngier , Kai-Heng Feng , Konrad Rzeszutek Wilk , David Rientjes , sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [RFC PATCH v4 10/21] watchdog/hardlockup: Add function to enable NMI watchdog on all allowed CPUs at once Date: Thu, 23 May 2019 18:16:12 -0700 Message-Id: <1558660583-28561-11-git-send-email-ricardo.neri-calderon@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1558660583-28561-1-git-send-email-ricardo.neri-calderon@linux.intel.com> References: <1558660583-28561-1-git-send-email-ricardo.neri-calderon@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When there are more than one implementation of the NMI watchdog, there may be situations in which switching from one to another is needed (e.g., if the time-stamp counter becomes unstable, the HPET-based NMI watchdog can no longer be used. The perf-based implementation of the hardlockup detector makes use of various per-CPU variables which are accessed via this_cpu operations. Hence, each CPU needs to enable its own NMI watchdog if using the perf implementation. Add functionality to switch from one NMI watchdog to another and do it from each allowed CPU. Cc: "H. Peter Anvin" Cc: Ashok Raj Cc: Andi Kleen Cc: Tony Luck Cc: "Rafael J. Wysocki" Cc: Don Zickus Cc: Nicholas Piggin Cc: Michael Ellerman Cc: Frederic Weisbecker Cc: Alexei Starovoitov Cc: Babu Moger Cc: "David S. Miller" Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Mathieu Desnoyers Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Andrew Morton Cc: Philippe Ombredanne Cc: Colin Ian King Cc: Byungchul Park Cc: "Paul E. McKenney" Cc: "Luis R. Rodriguez" Cc: Waiman Long Cc: Josh Poimboeuf Cc: Randy Dunlap Cc: Davidlohr Bueso Cc: Marc Zyngier Cc: Kai-Heng Feng Cc: Konrad Rzeszutek Wilk Cc: David Rientjes Cc: Stephane Eranian Cc: Suravee Suthikulpanit Cc: "Ravi V. Shankar" Cc: x86@kernel.org Cc: sparclinux@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Ricardo Neri --- include/linux/nmi.h | 2 ++ kernel/watchdog.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/linux/nmi.h b/include/linux/nmi.h index e5f1a86e20b7..6d828334348b 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -83,9 +83,11 @@ static inline void reset_hung_task_detector(void) { } #if defined(CONFIG_HARDLOCKUP_DETECTOR) extern void hardlockup_detector_disable(void); +extern void hardlockup_start_all(void); extern unsigned int hardlockup_panic; #else static inline void hardlockup_detector_disable(void) {} +static inline void hardlockup_start_all(void) {} #endif #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 7f9e7b9306fe..be589001200a 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -566,6 +566,21 @@ int lockup_detector_offline_cpu(unsigned int cpu) return 0; } +static int hardlockup_start_fn(void *data) +{ + watchdog_nmi_enable(smp_processor_id()); + return 0; +} + +void hardlockup_start_all(void) +{ + int cpu; + + cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask); + for_each_cpu(cpu, &watchdog_allowed_mask) + smp_call_on_cpu(cpu, hardlockup_start_fn, NULL, false); +} + static void lockup_detector_reconfigure(void) { cpus_read_lock(); -- 2.17.1