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,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 DC30EC43381 for ; Sat, 30 Mar 2019 01:31:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AC242218A6 for ; Sat, 30 Mar 2019 01:31:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909503; bh=Ax7z+jaG1F8bqsO5V85H6yQ/4cjlVVJjQmO3GPQOoB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k2CEcLKWyUJF8QnRHMIw8gKldNfxyCTkUiP5PS3uLBlXy+5TXNsnDC8so8oHkgZ+y eZtNdCXb8z7967yQcACw17GNMrkVSLLUAaj/Xqu7gFrqWMGJpPe3Rn84H986EJr7sy bkemRxvdCdE5Md13hGE8MI1N6iZT+hgi8z7Abjls= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732139AbfC3Bbm (ORCPT ); Fri, 29 Mar 2019 21:31:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:39392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732097AbfC3Bbk (ORCPT ); Fri, 29 Mar 2019 21:31:40 -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 DA407217F5; Sat, 30 Mar 2019 01:31:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909499; bh=Ax7z+jaG1F8bqsO5V85H6yQ/4cjlVVJjQmO3GPQOoB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zm8lYE3CM7I+MK9bpAEXLdIUJ2KkkQ2BWz/AaaPGO5vehWvZsf7kjqpRy1uFWf/5n zSyO9i99yCPElOIF9lmkQL8ql0ENMCENz4jgAEHPaPlRqbFZNwrrw2YgWPImIPPOkP bf2ilToVSMwX2BNm0A2mFvzAWlcrs7XXp12gOXFE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vitaly Kuznetsov , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH AUTOSEL 4.9 11/21] kernel: hung_task.c: disable on suspend Date: Fri, 29 Mar 2019 21:31:02 -0400 Message-Id: <20190330013112.784-11-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330013112.784-1-sashal@kernel.org> References: <20190330013112.784-1-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 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