From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 219506B0055 for ; Mon, 25 May 2009 12:08:23 -0400 (EDT) Message-ID: <4A1AC234.9020307@kernel.org> Date: Tue, 26 May 2009 01:07:16 +0900 From: Tejun Heo MIME-Version: 1.0 Subject: Re: [PATCH 3/7] percpu: clean up percpu variable definitions References: <1242805059-18338-1-git-send-email-tj@kernel.org> <1242805059-18338-4-git-send-email-tj@kernel.org> <200905251537.35981.rusty@rustcorp.com.au> In-Reply-To: <200905251537.35981.rusty@rustcorp.com.au> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Rusty Russell Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, x86@kernel.org, ink@jurassic.park.msu.ru, rth@twiddle.net, linux@arm.linux.org.uk, hskinnemoen@atmel.com, cooloney@kernel.org, starvik@axis.com, jesper.nilsson@axis.com, dhowells@redhat.com, ysato@users.sourceforge.jp, tony.luck@intel.com, takata@linux-m32r.org, geert@linux-m68k.org, monstr@monstr.eu, ralf@linux-mips.org, kyle@mcmartin.ca, benh@kernel.crashing.org, paulus@samba.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, lethal@linux-sh.org, davem@davemloft.net, jdike@addtoit.com, chris@zankel.net, Jens Axboe , Dave Jones , Jeremy Fitzhardinge , linux-mm List-ID: Rusty Russell wrote: > On Wed, 20 May 2009 05:07:35 pm Tejun Heo wrote: >> Percpu variable definition is about to be updated such that >> >> * percpu symbols must be unique even the static ones >> >> * in-function static definition is not allowed > > That spluttering noise is be choking on the title of this patch :) > > Making these pseudo statics is in no way a cleanup. How about we just > say "they can't be static" and do something like: > > /* Sorry, can't be static: that breaks archs which need these weak. */ > #define DEFINE_PER_CPU(type, var) \ > extern typeof(type) var; DEFINE_PER_CPU_SECTION(type, name, "") Heh... well, even though I authored the patch, I kind of agree with you. Maybe it would be better to simply disallow static declaration / definition at all. I wanted to give a go at the original idea as it seemed to have some potential. The result isn't too disappointing but I can't really say there are distinctively compelling advantages to justify the added complexity and subtlety. What do others think? Is everyone happy with going extern only? Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org