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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 6F83DC43461 for ; Thu, 1 Apr 2021 03:33:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E6D061006 for ; Thu, 1 Apr 2021 03:33:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233615AbhDADcW (ORCPT ); Wed, 31 Mar 2021 23:32:22 -0400 Received: from mail-m118208.qiye.163.com ([115.236.118.208]:40052 "EHLO mail-m118208.qiye.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233092AbhDADcL (ORCPT ); Wed, 31 Mar 2021 23:32:11 -0400 Received: from vivo-HP-ProDesk-680-G4-PCI-MT.vivo.xyz (unknown [58.251.74.232]) by mail-m118208.qiye.163.com (Hmail) with ESMTPA id 8AB01E00BD; Thu, 1 Apr 2021 11:32:07 +0800 (CST) From: Wang Qing To: Jonathan Corbet , Joe Perches , Wang Qing , Mauro Carvalho Chehab , Stephen Kitt , Andrew Morton , Kees Cook , Randy Dunlap , "Guilherme G. Piccoli" , Eric Biggers , Qais Yousef , Petr Mladek , Vlastimil Babka , Santosh Sivaraj , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Al Viro Cc: gregkh@linuxfoundation.org Subject: [PATCH V2 3/4] doc: watchdog: Modify the explanation related to watchdog thread Date: Thu, 1 Apr 2021 11:31:33 +0800 Message-Id: <1617247900-23813-4-git-send-email-wangqing@vivo.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1617247900-23813-1-git-send-email-wangqing@vivo.com> References: <1617247900-23813-1-git-send-email-wangqing@vivo.com> X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgYFAkeWUFZS1VLWVdZKFlBSE83V1ktWUFJV1kPCR oVCBIfWUFZTk1PTxkdTh8aS0IeVkpNSkxJT0xCSEtLT05VEwETFhoSFyQUDg9ZV1kWGg8SFR0UWU FZT0tIVUpKS0hKTFVLWQY+ X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6NyI6SBw4PT8LFjQhSRFDPRoK TRlPC0hVSlVKTUpMSU9MQkhLSEpKVTMWGhIXVQwaFRwKEhUcOw0SDRRVGBQWRVlXWRILWUFZTkNV SU5KVUxPVUlISVlXWQgBWUFITkxLNwY+ X-HM-Tid: 0a788b7cff762c17kusn8ab01e00bd Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org "watchdog/%u" threads has be replaced by cpu_stop_work. The current description is extremely misleading. Signed-off-by: Wang Qing --- Documentation/admin-guide/lockup-watchdogs.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/lockup-watchdogs.rst b/Documentation/admin-guide/lockup-watchdogs.rst index 290840c..3e09284 --- a/Documentation/admin-guide/lockup-watchdogs.rst +++ b/Documentation/admin-guide/lockup-watchdogs.rst @@ -39,7 +39,7 @@ in principle, they should work in any architecture where these 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 during that time the 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) -- 2.7.4