Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756425AbZDKByn (ORCPT ); Fri, 10 Apr 2009 21:54:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752272AbZDKBy0 (ORCPT ); Fri, 10 Apr 2009 21:54:26 -0400 Received: from hera.kernel.org ([140.211.167.34]:47965 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754826AbZDKByZ (ORCPT ); Fri, 10 Apr 2009 21:54:25 -0400 Message-ID: <49DFF7EA.900@kernel.org> Date: Fri, 10 Apr 2009 18:52:42 -0700 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Rusty Russell CC: Ivan Kokshaysky , Martin Schwidefsky , Ingo Molnar , tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, Paul Mundt , rmk@arm.linux.org.uk, starvik@axis.com, ralf@linux-mips.org, davem@davemloft.net, cooloney@kernel.org, kyle@mcmartin.ca, matthew@wil.cx, grundler@parisc-linux.org, takata@linux-m32r.org, benh@kernel.crashing.org, rth@twiddle.net, heiko.carstens@de.ibm.com Subject: Re: [GIT RFC] percpu: use dynamic percpu allocator as the default percpu allocator References: <49D3231D.2040403@kernel.org> <20090409094713.GA6538@jurassic.park.msu.ru> <49DDE1B5.4070407@kernel.org> <200904111108.08323.rusty@rustcorp.com.au> In-Reply-To: <200904111108.08323.rusty@rustcorp.com.au> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Sat, 11 Apr 2009 01:52:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1710 Lines: 43 Rusty Russell wrote: > On Thu, 9 Apr 2009 09:23:25 pm Tejun Heo wrote: >> It's generally a good idea to use uniquely >> distinguisible identifier for static symbols anyway to help debugging. > > Sorry, I can't let this statement stand. It's completely wrong: use the > shortest clear name, always. Heh... well, yeah, I don't think this is something everyone can agree about. I generally like having proper prefix for static symbols. It makes symbols more consistent too. >> If this limitation is acceptable, I think we should also add the dup >> build failure thing to the generic definition too tho so that such >> cases can be discovered before they hit alpha and s390 later. >> >> Any objections? > > Yes. If we decide that static per-cpu is unsupportable, let's not > hide the damn thing. We just make it give a compile warning if we > can, patch out the current cases, and make checkpatch.pl warn on new > ones. > > Don't silently override "static". Don't come up with stupid > justifications. Accept with open-eyes that it's evil, just a lesser > evil. It's different tho. With the right tricks, we can still make percpu variables defined static unusable from other compile units. ie. if we make the combination of DECLARE_PER_CPU() and static DEFINE_PER_CPU() trigger compile error, most of what the programmer meant by 'static' can be achieved whether the symbol itself ends up visible outside of the compile unit or not. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/