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Date: Mon, 7 May 2012 14:32:18 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Russ Anderson <rja@sgi.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Yinghai Lu <yinghai@kernel.org>, David Miller <davem@davemloft.net>
Subject: Re: [patch] mm: nobootmem: fix sign extend problem in
 __free_pages_memory()
Message-Id: <20120507143218.e8cc5584.akpm@linux-foundation.org>
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On Mon, 7 May 2012 14:32:03 -0500
Russ Anderson <rja@sgi.com> wrote:

> Systems with 8 TBytes of memory or greater can hit a problem 
> where only the the first 8 TB of memory shows up.

erk.

>  This is
> due to "int i" being smaller than "unsigned long start_aligned",
> causing the high bits to be dropped.
> 
> The fix is to change i to unsigned long to match start_aligned
> and end_aligned.
> 
> Thanks to Jack Steiner (steiner@sgi.com) for assistance tracking
> this down.
> 

I added the Cc: <stable@vger.kernel.org> to this.  The fix is small and
safe and someone might want to run older kernels on such a machine.