From owner-freebsd-arch@freebsd.org Wed Oct 19 11:21:44 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 DE939C1894B for ; Wed, 19 Oct 2016 11:21:44 +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 3E445908 for ; Wed, 19 Oct 2016 11:21:44 +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 OAA29194; Wed, 19 Oct 2016 14:21:42 +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 1bwowI-00028M-Ka; Wed, 19 Oct 2016 14:21:42 +0300 Subject: Re: watchdog end-user interface To: Poul-Henning Kamp References: <21377.1476875898@critter.freebsd.dk> Cc: freebsd-arch@FreeBSD.org From: Andriy Gapon Message-ID: Date: Wed, 19 Oct 2016 14:20:46 +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: <21377.1476875898@critter.freebsd.dk> Content-Type: text/plain; charset=windows-1252 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: Wed, 19 Oct 2016 11:21:45 -0000 On 19/10/2016 14:18, Poul-Henning Kamp wrote: > -------- > In message , Andriy Gapon wri > tes: > >> I want to question if those options really belong to watchdogd. >> When a watchdog timer expires that results in a system-wide action (like a >> system reset). To me, that implies that there should be a single system-wide >> configuration point. And I am not sure that the daemon is the best choice for it. > > The reason I originally put it in a daemon, was to have the watchdog > implicitly test the kernels ability to schedule trivial processes. > > It used to be, and may still be so that, there are deadlocks where > the kernel was twiddling its thumbs but userland did not progress. > Typical triggers for this are disk-I/O errors, corrupt filesystems, > memory overcommit etc. > > A kernel-only watchdog patter would not trigger in that case. I addressed this further down my post. Just in case, I think that watchdogd should do the pat-pats as it does now. But that's different from setting the timeout. -- Andriy Gapon