From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266477AbUFQNDj (ORCPT ); Thu, 17 Jun 2004 09:03:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266481AbUFQNDj (ORCPT ); Thu, 17 Jun 2004 09:03:39 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:690 "EHLO fgwmail7.fujitsu.co.jp") by vger.kernel.org with ESMTP id S266479AbUFQNDe (ORCPT ); Thu, 17 Jun 2004 09:03:34 -0400 Date: Thu, 17 Jun 2004 22:04:49 +0900 From: Takao Indoh Subject: Re: [3/4] [PATCH]Diskdump - yet another crash dump function In-reply-to: <20040617121356.GA24338@elte.hu> To: Ingo Molnar Cc: 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: <20040617121356.GA24338@elte.hu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. > >what do you think? > It sounds good because change of timer/tasklet code is not needed. But, I wonder whether this method is safe. For example, if kernel crashes because of problem of timer, clearing lists may be dangerous before dumping. Is it possible to clear all timer lists safely? Best Regards, Takao Indoh