From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Seemanta Dutta <seemanta@codeaurora.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: kdump: Trouble reading /dev/oldmem from capture kernel
Date: Tue, 9 Aug 2011 10:41:41 +0300 [thread overview]
Message-ID: <20110809074141.GF16790@intel.com> (raw)
In-Reply-To: <3f4665f1a191945db7c1711ecd154509.squirrel@www.codeaurora.org>
On Fri, Aug 05, 2011 at 02:01:03PM -0700, Seemanta Dutta wrote:
>
> 2. Dump capture kernel provides two interfaces to access 'old' kernel
> memory (as per kdump dpcumentation): /dev/oldmem and /proc/vmcore. The
> latter works perfectly. But I am more interested in the raw memory, rather
> than the core file.
Is there some specific reason to use /dev/oldmem instead? At least I've
never needed that interface. crash utility works pretty well with
/dev/vmcore.
> My expectation in this scenario was that I would be able to access entire
> physical RAM using the /dev/oldmem device. But turns out, I can't.
>
> I would be grateful if anyone pointed out if I was doing something wrong
> or missing something.
>
> This is happening over ARM. Could that have to do something with this ?
> Not sure if the ARM integration of KDUMP/KEXEC has something to do with
> it.
I haven't tried lately but it looks like ARM is missing setting of
'saved_max_pfn' which could explain why it works that way.
prev parent reply other threads:[~2011-08-09 7:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-05 21:01 kdump: Trouble reading /dev/oldmem from capture kernel Seemanta Dutta
2011-08-09 7:41 ` Mika Westerberg [this message]
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