Subject: Re: [PATCH 1/2] kdump: Allow shrinking of kdump region to be overridden

From: Américo Wang <[email-masked]>
Date: Wed, 9 Mar 2011 22:21:08 +0800

On Wed, Mar 09, 2011 at 11:46:57PM +1100, Anton Blanchard wrote:
>
>Hi,
>
>> The crashkernel region is specified via kernel cmdline, so why
>> not just drop a failure when it overlaps with RMO region?
>> Am I missing something?
>
>Unfortunately a ppc64 kernel requires a chunk of RMO memory. We would
>need the ability to specify multiple crashkernel regions - about 32MB
>in the RMO and the rest can be anywhere. That sounds pretty fragile for
>a user to configure successfully on the cmdline.
>
>Thats why the ppc64 crashkernel region begins mid way through the RMO
>region. It means both kernels get a chunk of RMO and we only have to
>deal with one crashkernel reservation in all the tools and
>documentation.
>

So, when I specify 128M in cmdline, 32M of them are RMO, and the
rest 96M are normal memory? And when I want to free all of them,
actually the 32M RMO will never be freed?