From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 01 May 2009 18:42:58 +0100 (BST) Received: from pfepb.post.tele.dk ([195.41.46.236]:46599 "EHLO pfepb.post.tele.dk" rhost-flags-OK-OK-OK-OK) by ftp.linux-mips.org with ESMTP id S20027248AbZEARmv (ORCPT ); Fri, 1 May 2009 18:42:51 +0100 Received: from ravnborg.org (x1-6-00-1e-2a-84-ae-3e.k225.webspeed.dk [80.163.61.94]) by pfepb.post.tele.dk (Postfix) with ESMTP id DAE74F8404D; Fri, 1 May 2009 19:42:47 +0200 (CEST) Received: by ravnborg.org (Postfix, from userid 500) id 09233580D0; Fri, 1 May 2009 19:44:58 +0200 (CEST) Date: Fri, 1 May 2009 19:44:57 +0200 From: Sam Ravnborg To: "H. Peter Anvin" Cc: Tim Abbott , Linux kernel mailing list , Anders Kaseorg , Waseem Daher , Denys Vlasenko , Jeff Arnold , Benjamin Herrenschmidt , Bryan Wu , Chris Zankel , Cyrill Gorcunov , David Howells , "David S. Miller" , dev-etrax@axis.com, Geert Uytterhoeven , Greg Ungerer , Haavard Skinnemoen , Heiko Carstens , Helge Deller , Hirokazu Takata , Ingo Molnar , Jeff Dike , Jesper Nilsson , Kyle McMartin , Linus Torvalds , linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@vger.kernel.org, linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, Martin Schwidefsky , Michal Simek , microblaze-uclinux@itee.uq.edu.au, Mikael Starvik , Paul Mackerras , Paul Mundt , Ralf Baechle , Richard Henderson , Roman Zippel , Russell King , sparclinux@vger.kernel.org, Thomas Gleixner , Tony Luck , uclinux-dist-devel@blackfin.uclinux.org, user-mode-linux-devel@lists.sourceforge.net, Yoshinori Sato Subject: Re: [PATCH v2 1/6] Add new macros for page-aligned data and bss sections. Message-ID: <20090501174457.GA26559@uranus.ravnborg.org> References: <1241121253-32341-1-git-send-email-tabbott@mit.edu> <1241121253-32341-2-git-send-email-tabbott@mit.edu> <20090501091848.GB18326@uranus.ravnborg.org> <49FB2449.1010301@zytor.com> <20090501171717.GA26401@uranus.ravnborg.org> <49FB2EDC.9050300@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49FB2EDC.9050300@zytor.com> User-Agent: Mutt/1.4.2.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 22596 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sam@ravnborg.org Precedence: bulk X-list: linux-mips On Fri, May 01, 2009 at 10:18:20AM -0700, H. Peter Anvin wrote: > Sam Ravnborg wrote: > > On Fri, May 01, 2009 at 09:33:13AM -0700, H. Peter Anvin wrote: > >> Tim Abbott wrote: > >>> On Fri, 1 May 2009, Sam Ravnborg wrote: > >>> > >>>> On Thu, Apr 30, 2009 at 03:54:08PM -0400, Tim Abbott wrote: > >>>>> +#define __PAGE_ALIGNED_DATA .section ".data.page_aligned", "aw", @progbits > >>>>> +#define __PAGE_ALIGNED_BSS .section ".bss.page_aligned", "aw", @nobits > >>>> It is my understanding that the linker will automatically > >>>> assume nobits for section names starting with .bss and likewise > >>>> progbits for section names starting with .data - so we can leave them out? > >>> I believe that is correct. > >>> > >> ... but that doesn't mean it's the right thing to do. > >> > >> It's better to be fully explicit when macroizing this kind of stuff. > >> This is part of why macroizing it is good: it means we end up with *one* > >> place that determines this stuff, not some magic heuristics in the linker. > > > > Do you know if we can use % in place of @? > > I could see that gas supports both - at least in trunk in cvs. > > > > I think it might depend on the architecture(!)... but it would > definitely have to be an issue with testing a bunch of different versions. > > What's wrong with @? arm does not support it :-( I recall it denote a comment in arm assembler. I could do some magic to detect the ARM case but I'm reluctant to do so. I could also ignore the arm issue for now as it is not used by arm, but that strikes me as the wrong approach. Sam