From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755954AbXFGLTx (ORCPT ); Thu, 7 Jun 2007 07:19:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751033AbXFGLTo (ORCPT ); Thu, 7 Jun 2007 07:19:44 -0400 Received: from nic.NetDirect.CA ([216.16.235.2]:42159 "EHLO rubicon.netdirect.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750870AbXFGLTo (ORCPT ); Thu, 7 Jun 2007 07:19:44 -0400 X-Originating-Ip: 72.143.66.27 Date: Thu, 7 Jun 2007 07:17:56 -0400 (EDT) From: "Robert P. J. Day" X-X-Sender: rpjday@localhost.localdomain To: Linux Kernel Mailing List Subject: why does the macro "ZERO_PAGE" take an argument? Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Net-Direct-Inc-MailScanner-Information: Please contact the ISP for more information X-Net-Direct-Inc-MailScanner: Found to be clean X-Net-Direct-Inc-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-16.8, required 5, autolearn=not spam, ALL_TRUSTED -1.80, BAYES_00 -15.00, INIT_RECVD_OUR_AUTH -20.00, RCVD_IN_SORBS_DUL 20.00) X-Net-Direct-Inc-MailScanner-From: rpjday@mindspring.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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? rday -- ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry Waterloo, Ontario, CANADA http://fsdev.net/wiki/index.php?title=Main_Page ========================================================================