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Date: Thu, 16 Dec 2004 19:31:43 -0800 (PST)
From: Christoph Lameter <clameter@sgi.com>
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To: William Lee Irwin III <wli@holomorphy.com>
cc: Hugh Dickins <hugh@veritas.com>, Nick Piggin <nickpiggin@yahoo.com.au>,
       Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@osdl.org>,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>, linux-mm@kvack.org,
       linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: page fault scalability patch V12 [0/7]: Overview and performance
 tests
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On Sun, 12 Dec 2004, William Lee Irwin III wrote:

> On Sun, Dec 12, 2004 at 09:33:11AM +0000, Hugh Dickins wrote:
> > Oh, hold on, isn't handle_mm_fault's pmd without page_table_lock
> > similarly racy, in both the 64-on-32 cases, and on architectures
> > which have a more complex pmd_t (sparc, m68k, h8300)?  Sigh.
>
> yes.

Those may fall back to use the page_table_lock for individual operations
that cannot be realized in an atomic way.