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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 6F51EC2D0DA for ; Thu, 26 Dec 2019 08:38:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 422B0206CB for ; Thu, 26 Dec 2019 08:38:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726597AbfLZIiO (ORCPT ); Thu, 26 Dec 2019 03:38:14 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:8185 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726460AbfLZIiO (ORCPT ); Thu, 26 Dec 2019 03:38:14 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id C9991AB0110524FB17B9; Thu, 26 Dec 2019 16:38:11 +0800 (CST) Received: from euler.huawei.com (10.175.104.193) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.439.0; Thu, 26 Dec 2019 16:38:00 +0800 From: Wei Li To: , , , , , , , CC: , Subject: [PATCH] sched/debug: Reset watchdog on all CPUs while processing sysrq-t Date: Thu, 26 Dec 2019 16:52:24 +0800 Message-ID: <20191226085224.48942-1-liwei391@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.104.193] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Lengthy output of sysrq-t may take a lot of time on slow serial console with lots of processes and CPUs. So we need to reset NMI-watchdog to avoid spurious lockup messages, and we also reset softlockup watchdogs on all other CPUs since another CPU might be blocked waiting for us to process an IPI or stop_machine. Add to sysrq_sched_debug_show() as what we did in show_state_filter(). Signed-off-by: Wei Li --- kernel/sched/debug.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index f7e4579e746c..879d3ccf3806 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -751,9 +751,16 @@ void sysrq_sched_debug_show(void) int cpu; sched_debug_header(NULL); - for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + /* + * Need to reset softlockup watchdogs on all CPUs, because + * another CPU might be blocked waiting for us to process + * an IPI or stop_machine. + */ + touch_nmi_watchdog(); + touch_all_softlockup_watchdogs(); print_cpu(NULL, cpu); - + } } /* -- 2.17.1