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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, URIBL_RED 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 15431C433B4 for ; Sun, 9 May 2021 23:28:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E51BC61424 for ; Sun, 9 May 2021 23:28:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229840AbhEIX31 (ORCPT ); Sun, 9 May 2021 19:29:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:46862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230017AbhEIX30 (ORCPT ); Sun, 9 May 2021 19:29:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1D792613E8; Sun, 9 May 2021 23:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1620602901; bh=uxGIIwv4JW3qmwyEEe1PCcpPX+fqXXKWMSg0X7bQAfU=; h=Date:From:To:Subject:From; b=S/bJvil9SJgicZYxQrgCRVuGUnBQnKnWyt1UiNuJyvDztbCVDin1cuPvkR7MwEkv2 E5/n4lpRP5rB5zOJMMI4TasN1kZoTzQ3UczY7+HrTHQxy0kTahk+8PjNCZ7UuK5uiD zqPE4TIjluE1kGNozFepvNfKhk9v3u+OHCvS9Clg= Date: Sun, 09 May 2021 16:28:20 -0700 From: akpm@linux-foundation.org To: corbet@lwn.net, gpiccoli@canonical.com, joe@perches.com, keescook@chromium.org, mchehab+huawei@kernel.org, mm-commits@vger.kernel.org, pmladek@suse.com, qais.yousef@arm.com, rdunlap@infradead.org, santosh@fossix.org, steve@sk2.org, vbabka@suse.cz, wangqing@vivo.com Subject: + doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch added to -mm tree Message-ID: <20210509232820.cZHjnLXkd%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: doc: watchdog: modify the explanation related to watchdog thread has been added to the -mm tree. Its filename is doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Wang Qing Subject: doc: watchdog: modify the explanation related to watchdog thread "watchdog/%u" threads has be replaced by cpu_stop_work. The current description is extremely misleading. Link: https://lkml.kernel.org/r/1619687073-24686-4-git-send-email-wangqing@vivo.com Signed-off-by: Wang Qing Reviewed-by: Petr Mladek Cc: "Guilherme G. Piccoli" Cc: Joe Perches Cc: Jonathan Corbet Cc: Kees Cook Cc: Mauro Carvalho Chehab Cc: Qais Yousef Cc: Randy Dunlap Cc: Santosh Sivaraj Cc: Stephen Kitt Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- Documentation/admin-guide/lockup-watchdogs.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/Documentation/admin-guide/lockup-watchdogs.rst~doc-watchdog-modify-the-explanation-related-to-watchdog-thread +++ a/Documentation/admin-guide/lockup-watchdogs.rst @@ -39,7 +39,7 @@ in principle, they should work in any ar subsystems are present. A periodic hrtimer runs to generate interrupts and kick the watchdog -task. An NMI perf event is generated every "watchdog_thresh" +job. An NMI perf event is generated every "watchdog_thresh" (compile-time initialized to 10 and configurable through sysctl of the same name) seconds to check for hardlockups. If any CPU in the system does not receive any hrtimer interrupt during that time the @@ -47,7 +47,7 @@ does not receive any hrtimer interrupt d generate a kernel warning or call panic, depending on the configuration. -The watchdog task is a high priority kernel thread that updates a +The watchdog job runs in a stop scheduling thread that updates a timestamp every time it is scheduled. If that timestamp is not updated for 2*watchdog_thresh seconds (the softlockup threshold) the 'softlockup detector' (coded inside the hrtimer callback function) _ Patches currently in -mm which might be from wangqing@vivo.com are kernel-watchdog-modify-the-explanation-related-to-watchdog-thread.patch doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch doc-watchdog-modify-the-doc-related-to-watchdog-%u.patch