From mboxrd@z Thu Jan  1 00:00:00 1970
From: "David S. Miller" <davem@davemloft.net>
Date: Sat, 28 Aug 2004 00:23:37 +0000
Subject: Re: page fault scalability patch final : i386 tested, x86_64
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To: Christoph Lameter <clameter@sgi.com>
Cc: ak@suse.de, akpm@osdl.org, wli@holomorphy.com, davem@redhat.com, raybry@sgi.com, ak@muc.de, benh@kernel.crashing.org, manfred@colorfullife.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, vrajesh@umich.edu, hugh@veritas.com

On Fri, 27 Aug 2004 17:19:11 -0700 (PDT)
Christoph Lameter <clameter@sgi.com> wrote:

> That is still 2^(32+12) = 2^44 = 16TB.

It's actually:

	2 ^ (31 + PAGE_SHIFT)

'31' because atomic_t is 'signed' and PAGE_SHIFT should
be obvious.

Christoph definitely has a point, this is even more virtual space
than most of the 64-bit platforms even support.  (Sparc64 is
2^43 and I believe ia64 is similar)  and this limit actually
mostly comes from the 3-level page table limits.