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From: "David S. Miller" <davem@redhat.com>
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Date: Sun, 6 May 2001 21:55:26 -0700 (PDT)
To: Jonathan Morton <chromi@cyberspace.org>
Cc: BERECZ Szabolcs <szabi@inf.elte.hu>, <linux-kernel@vger.kernel.org>,
        <linux-mm@kvack.org>
Subject: Re: page_launder() bug
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Jonathan Morton writes:
 > >-			 page_count(page) == (1 + !!page->buffers));
 > 
 > Two inversions in a row?

It is the most straightforward way to make a '1' or '0'
integer from the NULL state of a pointer.

Later,
David S. Miller
davem@redhat.com