From: Horst von Brand <vonbrand@inf.utfsm.cl>
To: "David S. Miller" <davem@redhat.com>
Cc: Jonathan Morton <chromi@cyberspace.org>,
BERECZ Szabolcs <szabi@inf.elte.hu>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: page_launder() bug
Date: Mon, 07 May 2001 10:52:02 -0400 [thread overview]
Message-ID: <200105071452.f47Eq2jn008611@pincoya.inf.utfsm.cl> (raw)
In-Reply-To: Message from "David S. Miller" <davem@redhat.com> of "Sun, 06 May 2001 21:55:26 MST." <15094.10942.592911.70443@pizda.ninka.net>
"David S. Miller" <davem@redhat.com> said:
> 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.
IMVHO, it is clearer to write:
page_count(page) == 1 + (page->buffers != NULL)
At least, the original poster wouldn't have wondered, and I wouldn't have
had to think a bit to find out what it meant... If gcc generates worse code
for this, it should be fixed.
--
Dr. Horst H. von Brand mailto:vonbrand@inf.utfsm.cl
Departamento de Informatica Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria +56 32 654239
Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513
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next prev parent reply other threads:[~2001-05-07 14:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-05-06 21:08 BERECZ Szabolcs
2001-05-06 21:59 ` Jonathan Morton
2001-05-06 22:07 ` BERECZ Szabolcs
2001-05-07 4:55 ` David S. Miller
2001-05-07 5:19 ` Aaron Lehmann
2001-05-07 6:26 ` Tobias Ringstrom
2001-05-07 8:54 ` David S. Miller
2001-05-07 15:12 ` Tobias Ringstrom
2001-05-07 10:52 ` Alan Cox
2001-05-07 13:49 ` Daniel Phillips
2001-05-07 14:52 ` Horst von Brand [this message]
2001-05-09 2:32 ` Rusty Russell
2001-05-09 3:36 ` Jonathan Morton
2001-05-09 8:43 ` Martin Dalecki
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