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To: Kris Kennaway <kris@FreeBSD.org>
From: Bengt Ahlgren <bengta@sics.se>
In-Reply-To: <471648B6.5020602@FreeBSD.org> (Kris Kennaway's message of
	"Wed, 17 Oct 2007 19:39:02 +0200")
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Date: Fri, 26 Oct 2007 12:22:23 +0200
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Cc: stable@FreeBSD.org
Subject: Re: Reproducable, possibly NFS related, fatal double fault in
 6.2-R-p7
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Kris Kennaway <kris@FreeBSD.org> writes:

> Bengt Ahlgren wrote:
>> Esa Karkkainen <ejk@iki.fi> writes:
>>
>>> On Sun, Oct 14, 2007 at 02:37:23PM +0200, Kris Kennaway wrote:
>>>> Esa Karkkainen wrote:
>>>>> 	I get "Fatal double fault" error when writing to a filesystem
>>>>> mounted from NFS server.
>>> I got an offlist reply in which he suggested that the problem might be
>>> in nve driver.
>> That was me.  I indeed got the same fault when running NFS over nve.
>> Switching to nfe solved the problem for me.  The on-screen backtrace
>> reveals the true location of the problem.  See:
>> http://www.sics.se/~bengta/FBSD/DSC00585.JPG
>> I do have a dump, but for some reason kgdb is not able to show the
>> same information.
>
> If you're using a module you have to do extra (but documented)
> steps. Or maybe kgdb has forgotten how to decode a double fault.

Just for the record: if_nve was compiled into the kernel.

Bengt