From owner-freebsd-arch@freebsd.org Thu Oct 20 07:15:33 2016 Return-Path: Delivered-To: freebsd-arch@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id EAFB4C19116 for ; Thu, 20 Oct 2016 07:15:33 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citapm.icyb.net.ua (citapm.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 3E42C266 for ; Thu, 20 Oct 2016 07:15:33 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citapm.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id KAA03011; Thu, 20 Oct 2016 10:15:31 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1bx7Zb-0003FM-Fx; Thu, 20 Oct 2016 10:15:31 +0300 Subject: Re: watchdog end-user interface To: Ngie Cooper References: <7a74df08-b5d9-5629-b71e-b577d8876e5d@freebsd.org> Cc: freebsd-arch@FreeBSD.org From: Andriy Gapon Message-ID: Date: Thu, 20 Oct 2016 10:14:35 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Oct 2016 07:15:34 -0000 On 20/10/2016 00:47, Ngie Cooper wrote: > On Wed, Oct 19, 2016 at 2:32 PM, Alfred Perlstein wrote: > ... >> Please look at the Linux interface for watchdogs, it is pretty good and >> could/should be ported to us. > > We (Isilon) also have a software watchdog implementation (in lieu of > IPMI+watchdogd) to make sure "userspace processes are making > progress". Please tell me more about this. It seems that there could be different definitions of 'software watchdog' and different expectations of what it should do. For example, we have SW_WATCHDOG in the tree for ages. It's a watchdog driver that's driver by clock interrupts and its logic is implemented in software. In the current implementation there is only one timeout action - a panic. Not too long ago Alfred added another software watchdog that's driven by callout-s. To me it's quite alike to SW_WATCHDOG, but it has configurable timeout actions: printf, log, panic, debugger. So, I wonder how Isilon's software watchdog is different from the above two. -- Andriy Gapon