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From: Mark Nelson <markn@au1.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH v2] powerpc: Track backing pages allocated by
	vmemmap_populate()
Date: Wed, 14 Apr 2010 09:38:46 +1000
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	<201004131602.23898.markn@au1.ibm.com>
	<1271157404.13059.102.camel@pasglop>
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On Tuesday 13 April 2010 21:16:44 Benjamin Herrenschmidt wrote:
> On Tue, 2010-04-13 at 16:02 +1000, Mark Nelson wrote:
> > That's a good question, and one that I probably should have added to
> > the
> > commit message.
> > But, following through, it looks like we end up calling into
> > __remove_section() from mm/memory_hotplug.c and if
> > CONFIG_SPARSEMEM_VMEMMAP is enabled we just return EBUSY as freeing
> > memmap with vmemmap isn't implemented yet.
> > 
> > So for the moment, I'm not sure we have to worry about it.
> 
> We probably don't. IE. The vmemmap will remain for those struct pages,
> which means they won't need to be allocated again if some memory is
> plugged back there. If not, we just waste a bit of memory. Not a big
> deal.
> 
Excellent! That makes sense.

Thanks Ben!

Mark.