Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756721AbXHISIa (ORCPT ); Thu, 9 Aug 2007 14:08:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752459AbXHISIN (ORCPT ); Thu, 9 Aug 2007 14:08:13 -0400 Received: from nic.NetDirect.CA ([216.16.235.2]:57729 "EHLO rubicon.netdirect.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755329AbXHISIL (ORCPT ); Thu, 9 Aug 2007 14:08:11 -0400 X-Originating-Ip: 72.143.66.27 Date: Thu, 9 Aug 2007 14:02:13 -0400 (EDT) From: "Robert P. J. Day" X-X-Sender: rpjday@localhost.localdomain To: Chris Snook cc: Jerry Jiang , Chris Friesen , Zan Lynx , Linux Kernel Mailing List Subject: Re: why are some atomic_t's not volatile, while most are? In-Reply-To: <46BB0E1F.2030003@redhat.com> Message-ID: References: <20070806123551.a6c3c154.wjiang@resilience.com> <46B72C58.5030502@redhat.com> <46B894E4.4010501@nortel.com> <46B8D6D7.2020206@redhat.com> <46B8DDF3.7050008@nortel.com> <46B8E1D3.8050501@redhat.com> <46B8E64E.7010708@nortel.com> <1186525977.232321.43.camel@localhost> <46B91D0C.5050704@redhat.com> <46B94B94.6000600@nortel.com> <46B96719.3050006@redhat.com> <20070808162755.61f50fbf.wjiang@resilience.com> <46BA2D72.9060202@redhat.com> <46BB0E1F.2030003@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Net-Direct-Inc-MailScanner-Information: Please contact the ISP for more information X-Net-Direct-Inc-MailScanner: Found to be clean X-Net-Direct-Inc-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-16.8, required 5, autolearn=not spam, ALL_TRUSTED -1.80, BAYES_00 -15.00, INIT_RECVD_OUR_AUTH -20.00, RCVD_IN_SORBS_DUL 20.00) X-Net-Direct-Inc-MailScanner-From: rpjday@mindspring.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1491 Lines: 39 On Thu, 9 Aug 2007, Chris Snook wrote: > Robert P. J. Day wrote: > > i'm almost scared to ask any more questions. :-) > > > > rday > > Momentarily I'll be posting a patchset that makes all atomic_t and > atomic64_t declarations non-volatile, and casts them to volatile > inside of atomic[64]_read. This will ensure consistent behavior > across all architectures, and is in keeping with the philosophy that > memory reads should be enforced in running code, not declarations. > > I hope you don't mind that we're mooting the question by making the > code more sensible. not at all, but it does bring up the obvious next question -- once all these definitions are made consistent, is there any reason some of that content can't be centralized in a single atomic.h header file, rather than duplicating it across a couple dozen architectures? surely, after this process, there's going to be some content that's identical across all arches, no? rday ======================================================================== Robert P. J. Day Linux Consulting, Training and Annoying Kernel Pedantry Waterloo, Ontario, CANADA http://fsdev.net/wiki/index.php?title=Main_Page ======================================================================== - 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/