Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751768AbWCDAAQ (ORCPT ); Fri, 3 Mar 2006 19:00:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751765AbWCDAAQ (ORCPT ); Fri, 3 Mar 2006 19:00:16 -0500 Received: from smtp.osdl.org ([65.172.181.4]:11197 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751766AbWCDAAO (ORCPT ); Fri, 3 Mar 2006 19:00:14 -0500 Date: Fri, 3 Mar 2006 15:59:13 -0800 From: Andrew Morton To: Linus Torvalds Cc: bunk@stusta.de, ".geert"@linux-m68k.org, zippel@linux-m68k.org, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org, nickpiggin@yahoo.com.au Subject: Re: 2.6.16-rc regression: m68k CONFIG_RMW_INSNS=n compile broken Message-Id: <20060303155913.2e299736.akpm@osdl.org> In-Reply-To: References: <20060303230149.GB9295@stusta.de> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1149 Lines: 30 Linus Torvalds wrote: > > > > On Sat, 4 Mar 2006, Adrian Bunk wrote: > > > > It seems the problem is that in the CONFIG_RMW_INSNS=n case, there's no > > cmpxchg #define in include/asm-m68k/system.h required for the > > atomic_add_unless #define in include/asm-m68k/atomic.h. > > Hmm. It seems like it never has been there.. Do you know what brought this > on? Was it Nick's RCU changes from "rcuref_dec_and_test()" to > "atomic_dec_and_test()" and friends? > > Judging by your error messages, I _think_ it's the "atomic_inc_not_zero()" > that gets expanded to a cmpxchg() that simply doesn't exist on m68k and > never has. > > I guess we've never depended on cmpxchg before. Or am I missing something? > Yes, we now require cmpxchg of all architectures. It's pretty simple to fix - just use local_irq_save(). We can steal the code from include/asm-m68knommu/system.h. - 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/