Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763046AbZCaWFe (ORCPT ); Tue, 31 Mar 2009 18:05:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757474AbZCaWFX (ORCPT ); Tue, 31 Mar 2009 18:05:23 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:40408 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757250AbZCaWFW (ORCPT ); Tue, 31 Mar 2009 18:05:22 -0400 Date: Tue, 31 Mar 2009 14:55:45 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Alan Cox cc: Ric Wheeler , "Andreas T.Auer" , Theodore Tso , Mark Lord , Stefan Richter , Jeff Garzik , Matthew Garrett , Andrew Morton , David Rees , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 In-Reply-To: <20090331221053.74354735@the-village.bc.nu> Message-ID: References: <49CD7B10.7010601@garzik.org> <49CD891A.7030103@rtr.ca> <49CD9047.4060500@garzik.org> <49CE2633.2000903@s5r6.in-berlin.de> <49CE3186.8090903@garzik.org> <49CE35AE.1080702@s5r6.in-berlin.de> <49CE3F74.6090103@rtr.ca> <20090329231451.GR26138@disturbed> <20090330003948.GA13356@mit.edu> <49D0710A.1030805@ursus.ath.cx> <20090330100546.51907bd2@the-village.bc.nu> <49D0A3D6.4000300@ursus.ath.cx> <49D0AA4A.6020308@redhat.com> <49D0EF1E.9040806@redhat.com> <20090331221053.74354735@the-village.bc.nu> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1107 Lines: 27 On Tue, 31 Mar 2009, Alan Cox wrote: > > How about the far more regular crash case ? We may be pretty reliable but > we are hardly indestructible especially on random boxes with funky BIOSes > or low grade hardware builds. The regular crash case doesn't need to care about the disk write-cache AT ALL. The disk will finish the writes on its own long after the kernel crashed. That was my _point_. The write cache on the disk is generally a whole lot safer than the OS data cache. If there's a catastrophic software failure (outside of the disk firmware itself ;), then the OS data cache is gone. But the disk write cache will be written back. Of course, if you have an automatic and immediate "power-off-on-oops", you're screwed, but if so, you have bigger problems anyway. You need to wait at _least_ a second or two before you power off. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/