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Date: Tue, 4 Apr 2006 08:21:33 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
To: Nick Piggin <npiggin@suse.de>
cc: Andrew Morton <akpm@osdl.org>, Linux Kernel <linux-kernel@vger.kernel.org>,
       Linux Memory Management <linux-mm@kvack.org>
Subject: Re: [patch 2/3] mm: speculative get_page
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On Tue, 4 Apr 2006, Nick Piggin wrote:

> +	/*
> +	 * PageNoNewRefs is set in order to prevent new references to the
> +	 * page (eg. before it gets removed from pagecache). Wait until it
> +	 * becomes clear (and checks below will ensure we still have the
> +	 * correct one).
> +	 */
> +	while (unlikely(PageNoNewRefs(page)))
> +		cpu_relax();

That part looks suspiciously like we need some sort of lock here.