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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Josh Boyer <jwboyer@linux.vnet.ibm.com>
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Date: Tue, 04 Nov 2008 07:17:42 +1100
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Cc: Wolfgang Denk <wd@denx.de>, Ilya Yanok <yanok@emcraft.com>,
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On Mon, 2008-11-03 at 06:26 -0500, Josh Boyer wrote:
> On Mon, 03 Nov 2008 11:43:54 +1100
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> 
> > 
> > > Cropping the size of the memory node.  That was simplest to do from the
> > > cuboot wrapper at the time.  If marking it reserved via a reserve map
> > > is more elegant and correct, we could do that.
> > > 
> > > But I will still like to know what about the other way is hairy please.
> > 
> > I don't like it :-) Bad feeling ... don't like having a memory
> > node entry that isn't aligned to some large power of two typically.
> 
> Erm, ok.  And does your heebie-geebies extend to people using the mem=
> parameter in a similar fashion?

Nah, not really. It's not that it won't work, I suppose it does, though
I would have preferred a way to "reserve" that memory rather than take
it off. In fact, that last page could be used for other things, for
example it could be used as a dummy page to point stale DMA to or
whatever else.

Ben.