From owner-freebsd-hackers@freebsd.org Thu Nov 14 15:35:10 2019 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 1487D1AB5F7 for ; Thu, 14 Nov 2019 15:35:10 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) Received: from kabab.cs.huji.ac.il (kabab.cs.huji.ac.il [132.65.116.210]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 47DQXY2GxMz46jD for ; Thu, 14 Nov 2019 15:35:08 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=cs.huji.ac.il; s=57791128; h=To:References:Message-Id:Content-Transfer-Encoding:Cc:Date:In-Reply-To:From:Subject:Mime-Version:Content-Type; bh=LPfkPJXZ5SAYhzQ0NPHh9EYaKtvb4jK6I+dEyYbeOyU=; b=2AygW/a/Rgx5LeB03NFH3+MqbfgwR9gK9OC/bk3ic/H+FbsI6G0ROhdN18C8IZdI7eCxiroqXskC7S6fYhbOSS0YSOhDnYN5uSD4hqakm2dm48JClzwQrxE0NNIzUuYhH60h4FK7afVxPapmT+LBTZwwxDMTrQOMZPYSe3wzmPUgmgFX3NCWN7MtvAY3Tj0pjkDohQQvvWG/nQbJ8qnD6qdkbuZvwtOj7pY6Nt2JjOBX2YZKc9Bzx8CkSgvj9YtLL67bctk8cl4qnuxbkaKW4owTM7zPTL6cjR5WoUUf+cB9IelEAE02GZ5Sy/oMteX4oFtrgERKAGNbg3JyAa/QRQ==; Received: from macmini.bk.cs.huji.ac.il ([132.65.179.19]) by kabab.cs.huji.ac.il with esmtp id 1iVH9G-000Dhv-89; Thu, 14 Nov 2019 17:35:06 +0200 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3601.0.10\)) Subject: Re: can the hardware watchdog reboot a hung kernel? From: Daniel Braniss In-Reply-To: <9cded04a-9ae1-881e-3962-7ef0322e96ed@grosbein.net> Date: Thu, 14 Nov 2019 17:35:06 +0200 Cc: freebsd-hackers Content-Transfer-Encoding: quoted-printable Message-Id: <2AD912BF-97B0-421D-B561-722D74864DC9@cs.huji.ac.il> References: <9cded04a-9ae1-881e-3962-7ef0322e96ed@grosbein.net> To: Eugene Grosbein X-Mailer: Apple Mail (2.3601.0.10) X-Rspamd-Queue-Id: 47DQXY2GxMz46jD X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=pass header.d=cs.huji.ac.il header.s=57791128 header.b=2AygW/a/; dmarc=pass (policy=none) header.from=huji.ac.il; spf=none (mx1.freebsd.org: domain of danny@cs.huji.ac.il has no SPF policy when checking 132.65.116.210) smtp.mailfrom=danny@cs.huji.ac.il X-Spamd-Result: default: False [-1.99 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.99)[-0.994,0]; R_DKIM_ALLOW(-0.20)[cs.huji.ac.il:s=57791128]; FROM_HAS_DN(0.00)[]; MV_CASE(0.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[cs.huji.ac.il:+]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[210.116.65.132.list.dnswl.org : 127.0.10.0]; DMARC_POLICY_ALLOW(-0.50)[huji.ac.il,none]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:378, ipnet:132.64.0.0/13, country:IL]; MID_RHS_MATCH_FROM(0.00)[]; IP_SCORE(-0.70)[ip: (-1.40), ipnet: 132.64.0.0/13(-1.20), asn: 378(-0.96), country: IL(0.05)]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Nov 2019 15:35:10 -0000 > On 14 Nov 2019, at 17:28, Eugene Grosbein wrote: >=20 > 14.11.2019 21:52, Daniel Braniss wrote: >=20 >> hi, >> I have serveral hundred Nano-pi NEO running, and sometimes they hang, = since there is no console >> available, the only solution is to do a power cycle - not so easy = since they are distributed in three buildings :-) >>=20 >> I am looking at the watchdog stuff, but it seems that what I want is = not supported, i.e. >> reboot the kernel when hung=20 >>=20 >> wishful thinking? >=20 > It's possible if the hardware has such a watchdog and kernel subsystem = watchdog(4) supports it. > rc.conf(5) manual page describes watchdogd_enable option. >=20 yes, but it relys on user land, what if the kernel is hung?=20