From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261474AbUJNLaE (ORCPT ); Thu, 14 Oct 2004 07:30:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261724AbUJNLaE (ORCPT ); Thu, 14 Oct 2004 07:30:04 -0400 Received: from omx1-ext.sgi.com ([192.48.179.11]:5799 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S261474AbUJNL3t (ORCPT ); Thu, 14 Oct 2004 07:29:49 -0400 Date: Thu, 14 Oct 2004 06:29:38 -0500 From: Robin Holt To: Itsuro Oda Cc: linux-kernel@vger.kernel.org, fastboot@osdl.org Subject: Re: Yet another crash dump tool Message-ID: <20041014112938.GE19122@lnx-holt.americas.sgi.com> References: <20041014074718.26E6.ODA@valinux.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041014074718.26E6.ODA@valinux.co.jp> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 14, 2004 at 08:05:41AM +0900, Itsuro Oda wrote: > Hello, > > We released a crash dump tool called "mini kernel dump". > > Please see the following URL to get the motivation and the > overview of the mini kernel dump. > http://mkdump.sourceforge.net/ > > http://sourceforge.net/projects/mkdump/ I am not sure why this is such a huge improvement. The one concern I have is you blindly are copying all of memory to the dump device. Can you dump device span multiple volumes? If I have a system using 1TB of physical memory, but 98% of that is allocated as huge TLB pages for users, do I _REALLY_ need to dump them all? lkcd, and I would hope others, only dump kernel pages unless configured to do otherwise. More importantly lkcd can eliminate page cache and buffer cache pages. Those types of pages are seldom relevant to figuring out what actually went wrong. Realistically, if the basic structures telling you whether pages are used by the kernel or not are so messed up you can not use them for dumping, they have probably been allocated to multiple users and will be riddled with inconsistent information. Robin Holt