Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751415AbWDACRA (ORCPT ); Fri, 31 Mar 2006 21:17:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751479AbWDACQ7 (ORCPT ); Fri, 31 Mar 2006 21:16:59 -0500 Received: from smtp110.mail.mud.yahoo.com ([209.191.85.220]:23913 "HELO smtp110.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751477AbWDACQ7 (ORCPT ); Fri, 31 Mar 2006 21:16:59 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=B7PovoOCTBGdw/X1wrZfZZcH5+lw1NqtHQO3jmjZ8KtE3NliQpjaS0q+hvIRrwSyLENyEnkxluZhf3hd7oPcUoytFEHmKHH4D4rJIAjynERXNcUhXTBnu5FKWc3fV0uON+X59SQOEhWNEm0ykXXXruKd0SA7oNW1Pq360KbbU8M= ; Message-ID: <442DE293.8020702@yahoo.com.au> Date: Sat, 01 Apr 2006 12:16:51 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Christoph Lameter CC: davem@davemloft.net, "Chen, Kenneth W" , Zoltan Menyhart , "Boehm, Hans" , "Grundler, Grant G" , akpm@osdl.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org Subject: Re: Synchronizing Bit operations V2 References: <200603312123.k2VLNqg06655@unix-os.sc.intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1102 Lines: 31 Christoph Lameter wrote: > On Fri, 31 Mar 2006, Chen, Kenneth W wrote: > > >>>I think we could say that lock semantics are different from barriers. They >>>are more like acquire and release on IA64. The problem with smb_mb_*** is >>>that the coder *explicitly* requested a barrier operation and we do not >>>give it to him. >> >>I was browsing sparc64 code and it defines: >> >>include/asm-sparc64/bitops.h: >>#define smp_mb__after_clear_bit() membar_storeload_storestore() >> >>With my very na?ve knowledge of sparc64, it doesn't look like a full barrier. >>Maybe sparc64 is broken too ... > > > Dave, how does sparc64 handle this situation? It looks like sparc64 always expects paired smp_mb__* operations, before and after the clear_bit. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/