Message-ID: <441A7E34.90508@sgi.com>
Date: Fri, 17 Mar 2006 10:15:32 +0100
From: Jes Sorensen <jes@sgi.com>
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To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@osdl.org>,
       linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, hch@lst.de,
       cotte@de.ibm.com, Hugh Dickins <hugh@veritas.com>
Subject: Re: [patch] mspec - special memory driver and do_no_pfn handler
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Benjamin Herrenschmidt wrote:
>> Quite frankly, I don't think nopfn() is a good interface. It's only usable 
>> for one single thing, so trying to claim that it's a generic VM op is 
>> really not valid. If (and that's a big if) we need this interface, we 
>> should just do it inside mm/memory.c instead of playing games as if it was 
>> generic.
> 
> Or just use sparsemem and create struct pages for your hw :) we do that
> for SPUs on Cell, works like a charm.

Well then the question is, would it simplify the code using no_pfn in
this case? Hacking up fake struct page entries seems even more of a
hack to me.

Cheers,
Jes

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