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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 00E31C10F14 for ; Thu, 18 Apr 2019 18:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7EBB218A1 for ; Thu, 18 Apr 2019 18:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555610920; bh=lK47yttyLG6+w2KdGbKrVhyUGeKIMNxq4mQdK4WoHIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PuJUBQxY+OfbL72Q4oxnGmFBspCKkNfFoJMaUZu6daBCEL/7cBSRA+iLXjTyNDui9 CBu3abxRwRMXLOYzUZNZ2HXq9CLbLYxBG/Wfh8PL8PKzlZu1dOPN6PHVCxq+bH08wq Rdi9qWVnUgvYv+Igv3EZ4gfTxR2H90IBirvbxBhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403886AbfDRSIj (ORCPT ); Thu, 18 Apr 2019 14:08:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:39694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403857AbfDRSIb (ORCPT ); Thu, 18 Apr 2019 14:08:31 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 83AD2206B6; Thu, 18 Apr 2019 18:08:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555610910; bh=lK47yttyLG6+w2KdGbKrVhyUGeKIMNxq4mQdK4WoHIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VeRzqFMggFqY0tbqr20IaTasEe0faJcyqncPQrQIRL7SNy9S3iW6DWXzuEXChdLp1 FdH3xWIwQdQN0OLPnySt/mXHY2nVMcBaYZldDYdfcgGCvlDpfS6DCur8mAaEcEoyaa 4LbKuOHHCEay1/CGj4qteCVlFtfttrlSCwDlDhg8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vitaly Kuznetsov , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 4.9 38/50] kernel: hung_task.c: disable on suspend Date: Thu, 18 Apr 2019 19:57:49 +0200 Message-Id: <20190418160427.194945585@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190418160422.455656724@linuxfoundation.org> References: <20190418160422.455656724@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit a1c6ca3c6de763459a6e93b644ec6518c890ba1c ] It is possible to observe hung_task complaints when system goes to suspend-to-idle state: # echo freeze > /sys/power/state PM: Syncing filesystems ... done. Freezing user space processes ... (elapsed 0.001 seconds) done. OOM killer disabled. Freezing remaining freezable tasks ... (elapsed 0.002 seconds) done. sd 0:0:0:0: [sda] Synchronizing SCSI cache INFO: task bash:1569 blocked for more than 120 seconds. Not tainted 4.19.0-rc3_+ #687 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. bash D 0 1569 604 0x00000000 Call Trace: ? __schedule+0x1fe/0x7e0 schedule+0x28/0x80 suspend_devices_and_enter+0x4ac/0x750 pm_suspend+0x2c0/0x310 Register a PM notifier to disable the detector on suspend and re-enable back on wakeup. Signed-off-by: Vitaly Kuznetsov Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- kernel/hung_task.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/kernel/hung_task.c b/kernel/hung_task.c index fd781a468f32..fb00cf30abd1 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -221,6 +222,28 @@ void reset_hung_task_detector(void) } EXPORT_SYMBOL_GPL(reset_hung_task_detector); +static bool hung_detector_suspended; + +static int hungtask_pm_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + switch (action) { + case PM_SUSPEND_PREPARE: + case PM_HIBERNATION_PREPARE: + case PM_RESTORE_PREPARE: + hung_detector_suspended = true; + break; + case PM_POST_SUSPEND: + case PM_POST_HIBERNATION: + case PM_POST_RESTORE: + hung_detector_suspended = false; + break; + default: + break; + } + return NOTIFY_OK; +} + /* * kthread which checks for tasks stuck in D state */ @@ -235,7 +258,8 @@ static int watchdog(void *dummy) long t = hung_timeout_jiffies(hung_last_checked, timeout); if (t <= 0) { - if (!atomic_xchg(&reset_hung_task, 0)) + if (!atomic_xchg(&reset_hung_task, 0) && + !hung_detector_suspended) check_hung_uninterruptible_tasks(timeout); hung_last_checked = jiffies; continue; @@ -249,6 +273,10 @@ static int watchdog(void *dummy) static int __init hung_task_init(void) { atomic_notifier_chain_register(&panic_notifier_list, &panic_block); + + /* Disable hung task detector on suspend */ + pm_notifier(hungtask_pm_notify, 0); + watchdog_task = kthread_run(watchdog, NULL, "khungtaskd"); return 0; -- 2.19.1