From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755178AbYANJRc (ORCPT ); Mon, 14 Jan 2008 04:17:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752743AbYANJRY (ORCPT ); Mon, 14 Jan 2008 04:17:24 -0500 Received: from pasmtpa.tele.dk ([80.160.77.114]:53085 "EHLO pasmtpA.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752562AbYANJRX (ORCPT ); Mon, 14 Jan 2008 04:17:23 -0500 Date: Mon, 14 Jan 2008 10:17:28 +0100 From: Sam Ravnborg To: Jan Beulich Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/4] __cpuinitconst and __devinitconst Message-ID: <20080114091728.GA6674@uranus.ravnborg.org> References: <47873D11.76E4.0078.0@novell.com> <20080111194428.GB29189@uranus.ravnborg.org> <20080112205635.GA6059@uranus.ravnborg.org> <20080113073024.GA30120@uranus.ravnborg.org> <20080113214204.GB2205@uranus.ravnborg.org> <478B2C6F.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <478B2C6F.76E4.0078.0@novell.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 14, 2008 at 08:33:35AM +0000, Jan Beulich wrote: > >>> Sam Ravnborg 13.01.08 22:42 >>> > >> And I found another small buglet too. I hope to post a complete > >> solution later today. > > > >The modpost bits turned out to take longer than expected so > >they are not done yet. The problem was the modpost structure > >were not prepared for adding such additional chacks. > >So I reworked those bits and the patch has been sent out for review. > > > >What follows here is the changes for init.h + all linker scripts > >to show the idea. > > > >Next step is to beat modpost in shape and to post this on linux-arch. > > > >Note - in -mm there are changes to init.h so the logic > >to decide type of __meminit notation is much simpler. > > Yes, I certainly like this concept. What I would have wanted in that patch, > though, is that the read-only data would right away be included in > RODATA() rather than being put in DATA_DATA. Will fix that in next patch. My focus was on the concept when I did the patch but it is dead easy to fix for ll archs at once. > Also, to shorten the > names a little, how about .{cpu,mem,dev}init.rodata? Good suggestion - will use these. > The one thing that I'm not sure is really consistent yet wrt. the > constification is that now you need to write e.g. > > static const char __cpuinitcdata example[]; > > and (accidentally) omitting the 'const' (as it's really an apparently > redundant thing now) as in > > static char __cpuinitcdata example[]; > > will cause section type conflicts (at the compiler or linker level). I > therefore think that the 'const' should really be part of the > __{cpu,mem,dev}cdata definitions (requiring the attribute to be > placed properly, namely placement at the end of a declaration as > is possible with __{cpu,mem,dev}initdata is then not an option here). I need to play a little with this before I make up my mind. I do not like the concpet of hiding the const too much - it will be non-obvious why the compiler complains if the only thing that distingush const from non-const is a small capital 'c' within __cpucinitdata (versus __cpuinitdata). It can always be an incremental patch as my concpet does not prevent it and we have only a few const __initdata variables. Sam