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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 3E734C433E7 for ; Thu, 3 Sep 2020 10:16:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F37AE20767 for ; Thu, 3 Sep 2020 10:16:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yadro.com header.i=@yadro.com header.b="bbycdTpB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728330AbgICKQN (ORCPT ); Thu, 3 Sep 2020 06:16:13 -0400 Received: from mta-02.yadro.com ([89.207.88.252]:56630 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726162AbgICKQJ (ORCPT ); Thu, 3 Sep 2020 06:16:09 -0400 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id 8FB6C542D3; Thu, 3 Sep 2020 10:16:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= content-transfer-encoding:mime-version:user-agent:content-type :content-type:organization:references:in-reply-to:date:date:from :from:subject:subject:message-id:received:received:received; s= mta-01; t=1599128166; x=1600942567; bh=hG/MCAQyYQhX01WN0uxqTRhm0 5X7D7VyvjKq75g9WDY=; b=bbycdTpBLRJu2pBDE9tj07vJLkIu/5VPMjpUdbpK6 BJOg11EHh9Tr2TBwfXc0eCRJR9H6IVPys8U/tE6hwQxAOgzO1cU8YpMF1vXq4LPb edqCyE2gFqfE1BiV6Yz9Es/gTmEbi6JCI6FGDNS6wbxcSZJ923vuAV3KCmxAN07b cI= X-Virus-Scanned: amavisd-new at yadro.com Received: from mta-01.yadro.com ([127.0.0.1]) by localhost (mta-01.yadro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id aH_ZQYl4KLGb; Thu, 3 Sep 2020 13:16:06 +0300 (MSK) Received: from T-EXCH-02.corp.yadro.com (t-exch-02.corp.yadro.com [172.17.10.102]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mta-01.yadro.com (Postfix) with ESMTPS id C8DB350242; Thu, 3 Sep 2020 13:16:05 +0300 (MSK) Received: from localhost.localdomain (10.199.2.130) by T-EXCH-02.corp.yadro.com (172.17.10.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.669.32; Thu, 3 Sep 2020 13:16:05 +0300 Message-ID: <6dd97c08809d576136d474f4b3f3b045a03634bb.camel@yadro.com> Subject: Re: watchdog start on restart From: Ivan Mikhaylov To: Christophe Leroy CC: Wim Van Sebroeck , Guenter Roeck , , Date: Thu, 3 Sep 2020 13:19:28 +0300 In-Reply-To: References: Organization: YADRO Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.5 (3.32.5-1.fc30) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.199.2.130] X-ClientProxiedBy: T-EXCH-01.corp.yadro.com (172.17.10.101) To T-EXCH-02.corp.yadro.com (172.17.10.102) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2020-09-02 at 15:19 +0200, Christophe Leroy wrote: > Isn't it the default expected behaviour for a watchdog ? It depends on hardware and system requirements. You may have not just one watchdog device. > "stop watchdog on restart" is there to keep things under control during > a wanted machine reboot/restart, while still having the watchdog do its > job on an unexpected restart. Yes, that's correct. > What would be the advantage of an ioctl() compared to the existing way ? You can control stop/start at any moment for any number of watchdog devices. Thanks.