From nobody Sat Feb 7 19:45:28 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 74060C7EE23 for ; Wed, 7 Jun 2023 18:13:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230503AbjFGSNd (ORCPT ); Wed, 7 Jun 2023 14:13:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231991AbjFGSNC (ORCPT ); Wed, 7 Jun 2023 14:13:02 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D90E295 for ; Wed, 7 Jun 2023 11:12:37 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id 98e67ed59e1d1-2568fc3d8a9so2963126a91.2 for ; Wed, 07 Jun 2023 11:12:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686161557; x=1688753557; 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=JPoC/y3KG/Q+B2RdcJtUx7SrMOC5cg46F1UuQnSSLXq4+eM8AiL8fX1iu/qBzQtxc8 g3Gc97P/CRY/UkDe5/dNICquALZBm11+nBqbl+VF63Hg2ZpOrjwTe8uo+w75eWkKp16k Qt7ri13PTI2EokvKr+1XCYE5L6gYhgDS/JPs79B4UL9KRDtv+rLWKhCvbILNAP8qrSqo cw/FW7rDmFjbr6np7uAXtui54yTseIYQlvtjZU6Rs7iMmqI72P58WL56NIG7fZjGMQgQ dDyIbJpJnQsFMta9F+mznMYM6e7pPckruRzA7bi1W1+1u1p8oZLe+f/8W7lNBpGlxfWS BIDw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686161557; x=1688753557; 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=Av+eooSM773mc5meMfjPJij3phKPtt9Q0p2X7SkS0YMA+ixOgyWtATvdjnxCkGSO8l vUODv2spsDqw7DrVBESCYcfaeOCT4rSs7O+hjNgRhfbvisZbK6tAgDm868C25okDWwLk ny5AA1HbbE5hirTvP2Lcf+R338+ms3FVh5w6K6g/7RfBRzdltR6sWBwiS1FijvCAMOp0 O+t9T/2Co1bvHaKF1+LE4LWzqe8/6vOLuN70WFeZnw/KH5vmIkXFhhSqLOcA+TLA3Bjz f+KQH31nLnXPZIhL6DKolVRPFtQKpC+CfCVXy10OaUukBDfIWy2NTjgRuI3NrKtKSTtp 4uWg== X-Gm-Message-State: AC+VfDwHpGbacewrBOIBgaHZdWijPFOsHa9TdM9dJ1ImVn8RCk6Yatgh H2QoPq8j/mGAHL4bFZRPFx8= X-Google-Smtp-Source: ACHHUZ71v+5zaWqi7ahXQ7Oxvby9IuRht0hEhPUtiWq6G00yQW1o+5g9Ljn48YLKwJpT/E0xSBpZWw== X-Received: by 2002:a17:90a:49:b0:259:343:86b5 with SMTP id 9-20020a17090a004900b00259034386b5mr2128951pjb.47.1686161557323; Wed, 07 Jun 2023 11:12:37 -0700 (PDT) Received: from VAN-928222-PC0.fortinet-us.com ([173.214.130.2]) by smtp.gmail.com with ESMTPSA id 15-20020a17090a004f00b0025352448ba9sm1791811pjb.0.2023.06.07.11.12.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jun 2023 11:12:36 -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 11:12:21 -0700 Message-Id: <20230607181221.4118381-1-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