From nobody Sat Feb 7 19:41:37 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4309EC7EE23 for ; Wed, 7 Jun 2023 18:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231977AbjFGSWv (ORCPT ); Wed, 7 Jun 2023 14:22:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232818AbjFGSW0 (ORCPT ); Wed, 7 Jun 2023 14:22:26 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79666E6C for ; Wed, 7 Jun 2023 11:21:51 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-650c8cb68aeso4304290b3a.3 for ; Wed, 07 Jun 2023 11:21:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686162110; x=1688754110; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=qV89SGlXzzybQ68Kw8PJEO9/Nh725SOfx0EhcbhN+uM=; b=CsvpAdfz+FpKfF+eNU1WwuJCSi+OkRfPodzVUkrx/GfkVKXEiV5slFtoBuMzy6vHym c3VNpZ0p917FK3HEDj1p2hMDDOja1FELK+lT96FDKoWH0ohKEUYWLGNQAtyIpslYZa78 UIS7FWI4mVeHHeponI2OlPV5LiSd3qKrlox/hx+6M7Kv2/fCmEfG7NwCIqgVJiluYVXa SrjL4lOaF2O7mLZoNdD906xey5xAXD+2xInP8Icos2Lm3HOiSTZht47y9LHXnVPTVfsV bCFgxqR2tGEHFBtHS+IvlH1mR3kmIvm5FxBTJYKoHL4eoipjnFhpA/q270Ye5MD2GrQI IQUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686162110; x=1688754110; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=qV89SGlXzzybQ68Kw8PJEO9/Nh725SOfx0EhcbhN+uM=; b=B7f/yj2yq+AaxVmI5nxxFJuzIWfOpPNTVPsVcwvzK+hK70A1Lp1X6mXr/Exl4tM5Is MwnOwtBbvO3KykYISMOpUM0dnxedfqkkZVYnhs9ortVkG1y4GvTImDMF+xZo0jtnu87C 3nfqOEGfx8epDtrppAyETQptxAx5y6W28pys/QoXW58VTIcguMUJDKZvEV10QDLU/7cz D6ZXUtmeFgyVPTWOfRzB4J8TlzA3h+MdlK1J4g5L+v/1laNg/UR7BnIKkV91sa19brGD RRtpEUYMM1JW31aI1mA902N7PDfQlKdJJwYHVtw1+LegjTBJ/YaW/loV6XOLfjZav1Hn t93g== X-Gm-Message-State: AC+VfDwZCF15XmSpfvHgf2dBvPFGzVLfoILSVuQJegf0Yo09o+fnXh82 ezKzo1WG3sJgqheNVyl5GwU= X-Google-Smtp-Source: ACHHUZ5IMsi4CD0h0RIWIAtqAa94c0huJdM4QururY1TsLDFSlRtz2KBaUEzVLNOQSq3Jsc6l7WlcQ== X-Received: by 2002:a05:6a20:914b:b0:10b:cb87:f5e with SMTP id x11-20020a056a20914b00b0010bcb870f5emr2041304pzc.45.1686162110413; Wed, 07 Jun 2023 11:21:50 -0700 (PDT) Received: from VAN-928222-PC0.fortinet-us.com ([173.214.130.2]) by smtp.gmail.com with ESMTPSA id j8-20020aa78d08000000b0065ebeb9bb23sm1645427pfe.149.2023.06.07.11.21.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jun 2023 11:21:49 -0700 (PDT) From: Qingjie Xing To: mingo@redhat.com Cc: peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, brauner@kernel.org, linux-kernel@vger.kernel.org, xqjcool@gmail.com Subject: [PATCH] sched/debug,sched/core: Reset hung task detector while processing sysrq-t Date: Wed, 7 Jun 2023 11:21:33 -0700 Message-Id: <20230607182133.4142729-1-xqjcool@gmail.com> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" On devices with multiple CPUs and multiple processes, outputting lengthy sysrq-t content on a slow serial port can consume a significant amount of time. We need to reset the hung task detector to avoid false hung task alerts. Signed-off-by: Qingjie Xing --- kernel/sched/core.c | 1 + kernel/sched/debug.c | 1 + 2 files changed, 2 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a68d1276bab0..5773283b752c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9176,6 +9176,7 @@ void show_state_filter(unsigned int state_filter) */ touch_nmi_watchdog(); touch_all_softlockup_watchdogs(); + reset_hung_task_detector(); if (state_filter_match(state_filter, p)) sched_show_task(p); } diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 0b2340a79b65..43065808b425 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -904,6 +904,7 @@ void sysrq_sched_debug_show(void) */ touch_nmi_watchdog(); touch_all_softlockup_watchdogs(); + reset_hung_task_detector(); print_cpu(NULL, cpu); } } --=20 2.40.1