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Date: Thu, 03 Feb 2011 13:07:02 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Ingo Molnar <mingo@elte.hu>
CC: Pavel Machek <pavel@ucw.cz>, Tejun Heo <tj@kernel.org>,
        "Ahmed S. Darwish" <darwish.07@gmail.com>,
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Subject: Re: [PATCH 0/2][concept RFC] x86: BIOS-save kernel log to disk upon
 panic
References: <20110125134748.GA10051@laptop> <20110125140948.GA26762@elte.hu> <20110125150834.GD27510@htj.dyndns.org> <20110203143644.GA4085@ucw.cz> <4D4AC996.4070307@zytor.com> <20110203175721.GB8785@elte.hu>
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On 02/03/2011 09:57 AM, Ingo Molnar wrote:
> 
> * H. Peter Anvin <hpa@zytor.com> wrote:
> 
>> On 02/03/2011 06:36 AM, Pavel Machek wrote:
>>>
>>> Could we read the log area, first, verify it contains signature, write
>>> it back?
>>> 								Pavel
>>
>> Yes, but that doesn't guarantee no data corruption caused by handing
>> over from one driver to another.
> 
> Waiting a few seconds? Is there any sufficiently high number of X where waiting X 
> seconds would make it safe to touch the hardware? (i.e. it would guarantee that 
> pending commands are flushed, etc.)
> 

Probably not... if you have enough control over the hardware to force a
device reset you should be okay, though.  This kind of comes down to
wanting a complete set of system drivers, i.e. kexec/kdump again.

	-hpa