From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pfepb.post.tele.dk (pfepb.post.tele.dk [195.41.46.236]) by ozlabs.org (Postfix) with ESMTP id 320BADDE19 for ; Sat, 2 May 2009 03:42:52 +1000 (EST) Date: Fri, 1 May 2009 19:44:57 +0200 From: Sam Ravnborg To: "H. Peter Anvin" 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 In-Reply-To: <49FB2EDC.9050300@zytor.com> Cc: linux-mips@linux-mips.org, linux-m68k@vger.kernel.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Denys Vlasenko , Tim Abbott , Heiko Carstens , linuxppc-dev@ozlabs.org, Paul Mackerras , Greg Ungerer , sparclinux@vger.kernel.org, Thomas Gleixner , linux-s390@vger.kernel.org, Jesper Nilsson , Yoshinori Sato , Helge Deller , Ingo Molnar , Geert Uytterhoeven , Russell King , user-mode-linux-devel@lists.sourceforge.net, microblaze-uclinux@itee.uq.edu.au, Jeff Dike , Jeff Arnold , dev-etrax@axis.com, Mikael Starvik , Cyrill Gorcunov , Michal Simek , Waseem Daher , Richard Henderson , Chris Zankel , Bryan Wu , Tony Luck , linux-parisc@vger.kernel.org, Haavard Skinnemoen , Hirokazu Takata , Linux kernel mailing list , Ralf Baechle , Anders Kaseorg , Kyle McMartin , Paul Mundt , linux-alpha@vger.kernel.org, Martin Schwidefsky , uclinux-dist-devel@blackfin.uclinux.org, Linus Torvalds , "David S. Miller" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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