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=-16.7 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 8AC0CC433B4 for ; Thu, 29 Apr 2021 09:05:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CE3F6143D for ; Thu, 29 Apr 2021 09:05:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240260AbhD2JFz (ORCPT ); Thu, 29 Apr 2021 05:05:55 -0400 Received: from mail-m17655.qiye.163.com ([59.111.176.55]:64146 "EHLO mail-m17655.qiye.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240247AbhD2JFx (ORCPT ); Thu, 29 Apr 2021 05:05:53 -0400 Received: from vivo-HP-ProDesk-680-G4-PCI-MT.vivo.xyz (unknown [58.250.176.229]) by mail-m17655.qiye.163.com (Hmail) with ESMTPA id A2623400B1; Thu, 29 Apr 2021 17:05:03 +0800 (CST) From: Wang Qing To: Jonathan Corbet , Wang Qing , Mauro Carvalho Chehab , Joe Perches , Stephen Kitt , Andrew Morton , Kees Cook , Randy Dunlap , "Guilherme G. Piccoli" , Qais Yousef , Petr Mladek , Santosh Sivaraj , Vlastimil Babka , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Lepton Wu Subject: [PATCH V2,RESEND 3/4] doc: watchdog: Modify the explanation related to watchdog thread Date: Thu, 29 Apr 2021 17:04:27 +0800 Message-Id: <1619687073-24686-4-git-send-email-wangqing@vivo.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1619687073-24686-2-git-send-email-wangqing@vivo.com> References: <1619687073-24686-2-git-send-email-wangqing@vivo.com> X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgYFAkeWUFZS1VLWVdZKFlBSE83V1ktWUFJV1kPCR oVCBIfWUFZQ0sYSVYZT0NDGR4fHx4YGE5VEwETFhoSFyQUDg9ZV1kWGg8SFR0UWUFZT0tIVUpKS0 hKTFVLWQY+ X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6MRw6PRw5NT8SKElCN0IsFytD LEwwFDJVSlVKTUpCTUNMSktPTklLVTMWGhIXVQwaFRwKEhUcOw0SDRRVGBQWRVlXWRILWUFZTkNV SU5LVUpMTVVJSUJZV1kIAVlBSE9PTTcG X-HM-Tid: 0a791cdfde86da01kuwsa2623400b1 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