Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266117AbUFUGYO (ORCPT ); Mon, 21 Jun 2004 02:24:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266128AbUFUGYO (ORCPT ); Mon, 21 Jun 2004 02:24:14 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:10711 "EHLO fgwmail6.fujitsu.co.jp") by vger.kernel.org with ESMTP id S266117AbUFUGYN (ORCPT ); Mon, 21 Jun 2004 02:24:13 -0400 Date: Mon, 21 Jun 2004 15:25:29 +0900 From: Takao Indoh Subject: Re: [3/4] [PATCH]Diskdump - yet another crash dump function In-reply-to: <1642.1087796771@kao2.melbourne.sgi.com> To: Keith Owens Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Christoph Hellwig , Andi Kleen Message-id: MIME-version: 1.0 X-Mailer: TuruKame 3.55 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT References: <1642.1087796771@kao2.melbourne.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1514 Lines: 35 Hi, On Mon, 21 Jun 2004 15:46:11 +1000, Keith Owens wrote: >On Thu, 17 Jun 2004 14:13:56 +0200, >Ingo Molnar wrote: >>but there's another possible method (suggested by Alan Cox) that >>requires no changes to the timer API hotpaths: 'clear' all timer lists >>upon a crash [once all CPUs have stopped and irqs are disabled] and just >>let the drivers use the normal timer APIs. Drive timer execution via a >>polling method. >> >>this basically approximates your polling based implementation but uses >>the existing kernel timer data structures and timer mechanism so should >>be robust and compatible. It doesnt rely on any previous state (because >>all currently pending timers are discarded) so it's as crash-safe as >>possible. > >Don't forget live crash dumping. The system is running and is behaving >strangely so you want to take a dump for investigation, but you do not >want to kill the system afterwards. Live crash dumping is very useful >for problem diagnosis. >It is a little more complex than dumping after an oops because you must >not destroy any kernel data, including timer lists. The method he proposed is used only when die/panic happens. Live dump is a function crash command provides throuth /dev/mem. Best Regards, Takao Indoh - 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/