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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: "Robert P. J. Day" <rpjday@mindspring.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: why does the macro "ZERO_PAGE" take an argument?
Date: Thu, 07 Jun 2007 21:29:28 +1000	[thread overview]
Message-ID: <4667EC18.4080904@yahoo.com.au> (raw)
In-Reply-To: <Pine.LNX.4.64.0706070715290.14293@localhost.localdomain>

Robert P. J. Day wrote:
>   probably making a fool of myself here, but what is the purpose of
> that single argument to the macro "ZERO_PAGE"?
> 
> $ grep -r "define ZERO_PAGE" include
> include/asm-frv/pgtable.h:#define ZERO_PAGE(vaddr)      ({ BUG(); NULL; })
> include/asm-frv/pgtable.h:#define ZERO_PAGE(vaddr)      virt_to_page(empty_zero_page)
> include/asm-v850/pgtable.h:#define ZERO_PAGE(vaddr)     ((void *)0x87654321)
> include/asm-mips/pgtable.h:#define ZERO_PAGE(vaddr) \
> include/asm-blackfin/pgtable.h:#define ZERO_PAGE(vaddr) (virt_to_page(0))
> include/asm-parisc/pgtable.h:#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
> include/asm-alpha/pgtable.h:#define ZERO_PAGE(vaddr)    (virt_to_page(ZERO_PGE))
> ...
> 
>   AFAICT, there are no definitions of that macro that actually use
> that argument.  is that some kind of historical cruft?

MIPS?

-- 
SUSE Labs, Novell Inc.

  reply	other threads:[~2007-06-07 11:29 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-07 11:17 why does the macro "ZERO_PAGE" take an argument? Robert P. J. Day
2007-06-07 11:29 ` Nick Piggin [this message]
2007-06-07 11:34   ` Robert P. J. Day
2007-06-07 11:39     ` Satyam Sharma
2007-06-07 11:53       ` Robert P. J. Day
2007-06-07 16:37         ` Ralf Baechle
2007-06-07 18:04           ` H. Peter Anvin
2007-06-07 17:32         ` H. Peter Anvin
2007-06-07 19:29           ` William Lee Irwin III
2007-06-07 21:16             ` H. Peter Anvin
2007-06-08  7:25               ` Robert P. J. Day
2007-06-09  0:49                 ` H. Peter Anvin
2007-06-12  2:18               ` Nick Piggin

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