From owner-freebsd-current@FreeBSD.ORG Tue Jan 11 20:45:46 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 71AF7106566B for ; Tue, 11 Jan 2011 20:45:46 +0000 (UTC) (envelope-from cpghost@cordula.ws) Received: from mail-qy0-f182.google.com (mail-qy0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id 2E4D88FC08 for ; Tue, 11 Jan 2011 20:45:45 +0000 (UTC) Received: by qyk36 with SMTP id 36so20369838qyk.13 for ; Tue, 11 Jan 2011 12:45:45 -0800 (PST) MIME-Version: 1.0 Received: by 10.229.225.5 with SMTP id iq5mr85492qcb.13.1294778267800; Tue, 11 Jan 2011 12:37:47 -0800 (PST) Received: by 10.229.102.19 with HTTP; Tue, 11 Jan 2011 12:37:47 -0800 (PST) X-Originating-IP: [93.221.179.70] In-Reply-To: <4D2CBE45.90209@delphij.net> References: <4D2CBE45.90209@delphij.net> Date: Tue, 11 Jan 2011 21:37:47 +0100 Message-ID: From: "C. P. Ghost" To: d@delphij.net Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: David DEMELIER , freebsd-current@freebsd.org Subject: Re: why panic(9) ? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jan 2011 20:45:46 -0000 On Tue, Jan 11, 2011 at 9:32 PM, Xin LI wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > On 01/11/11 12:11, David DEMELIER wrote: >> Yes, why this function exists? There is no way to solve a problem >> without panic'ing? Is panic really needed? Imagine someone working on > [...] > > Panic is used to stop the kernel in an aggressive way when data damage > is detected and the damage is already beyond what the kernel can recover > from. > > The kernel can and should be made more robust but no, I don't think we > can totally eliminate panic(). Exactly. One area where the kernel should be made more robust is UFS with disappearing disks (e.g. USB mounted file systems, or, as recently happened here with a loose external SATA cable). Panicing here is REALLY annoying. ;-) > Cheers, > - -- > Xin LI =A0 =A0http://www.delphij.net/ > FreeBSD - The Power to Serve! =A0 =A0 =A0 =A0 =A0Live free or die -cpghost. --=20 Cordula's Web. http://www.cordula.ws/