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Date: Fri, 27 Apr 2007 14:42:01 +0100
From: Christoph Hellwig <hch@infradead.org>
To: Paul Mackerras <paulus@samba.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>,
       Andrew Morton <akpm@linux-foundation.org>,
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       Jens Axboe <jens.axboe@oracle.com>,
       Badari Pulavarty <pbadari@gmail.com>,
       Maxim Levitsky <maximlevitsky@gmail.com>
Subject: Re: [00/17] Large Blocksize Support V3
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On Fri, Apr 27, 2007 at 10:14:20PM +1000, Paul Mackerras wrote:
> It's not as simple on 64-bit powerpc with the hash table of course,
> because the page size is chosen at the segment (256MB) level,
> restricting where we can put 64k and 16M pages to some degree.

I think Christoph's variable order pagecache should be perfectly
fine on ppc64.  We're selecting the pagesize on a per-file basis,
and the page size selection would choce which segement this mmap
gets into.  Ben's get_unmapped_area changes are very helpfull for that.