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,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D0CBFC43381 for ; Sat, 30 Mar 2019 01:29:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F3A821773 for ; Sat, 30 Mar 2019 01:29:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909391; bh=TFv+JxeVloS90cn9zwki6rqT548KK9QuyI9pViDC9Vc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZzpUKRjSvWVnJimImaL9LKHSPYxnIDUksrnOPw2XSWoBDm3xO3xf3bbytAYVKxygr gC1MNs1ReIRAPn+IreJuR3rb4RZ58WLxXfBM64aaiOFvm4FxdsRJUGvLPvnPGNORk9 Pci8uPtn/vyhMx/iEGH+UBiM6NF+AcnXKXzhDDKI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731095AbfC3B3u (ORCPT ); Fri, 29 Mar 2019 21:29:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:36668 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731179AbfC3B3p (ORCPT ); Fri, 29 Mar 2019 21:29:45 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2946F217F5; Sat, 30 Mar 2019 01:29:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909383; bh=TFv+JxeVloS90cn9zwki6rqT548KK9QuyI9pViDC9Vc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JA8lKWQmGZqfpc2t+lRn+Ibcrwoj03w0hELY3veTIwRoppi1GXdCwMs+APbxAZjhz yRjQF8fX85thedyanJXKx5PRwhkJ3OIsOboGnXesfM4VTI9Cj88IVGjyJ6otyiFv8j 8JEpQ3b8XYlADPKWKnHsAZHSr2hSXLS2vQUGT6mY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH AUTOSEL 4.19 26/57] kernel: hung_task.c: disable on suspend Date: Fri, 29 Mar 2019 21:28:19 -0400 Message-Id: <20190330012854.32212-26-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330012854.32212-1-sashal@kernel.org> References: <20190330012854.32212-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov [ 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 9eca2371f189..4a9191617076 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -240,6 +241,28 @@ 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 */ @@ -259,7 +282,8 @@ static int watchdog(void *dummy) interval = min_t(unsigned long, interval, timeout); t = hung_timeout_jiffies(hung_last_checked, interval); 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; @@ -273,6 +297,10 @@ 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