Date: Thu, 17 Jun 2004 22:04:49 +0900
From: Takao Indoh <indou.takao@soft.fujitsu.com>
Subject: Re: [3/4] [PATCH]Diskdump - yet another crash dump function
In-reply-to: <20040617121356.GA24338@elte.hu>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org, Christoph Hellwig <hch@infradead.org>,
       Andi Kleen <ak@muc.de>
Message-id: <CBC4546BAB9F1Aindou.takao@soft.fujitsu.com>
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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
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