Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757573AbYJIBSz (ORCPT ); Wed, 8 Oct 2008 21:18:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754768AbYJIBSq (ORCPT ); Wed, 8 Oct 2008 21:18:46 -0400 Received: from mx2.redhat.com ([66.187.237.31]:39221 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751690AbYJIBSq (ORCPT ); Wed, 8 Oct 2008 21:18:46 -0400 Message-ID: <48ED5BC6.8040006@redhat.com> Date: Wed, 08 Oct 2008 21:17:58 -0400 From: Chris Snook User-Agent: Thunderbird 2.0.0.17 (Macintosh/20080914) MIME-Version: 1.0 To: Randy Dunlap CC: Andrew Morton , Ben Hutchings , Mikulas Patocka , linux-kernel@vger.kernel.org, linux-mm@vger.kernel.org Subject: Re: [PATCH] documentation: explain memory barriers References: <20080911101616.GA24064@agk.fab.redhat.com> <20080923154905.50d4b0fa.akpm@linux-foundation.org> <20080923164623.ce82c1c2.akpm@linux-foundation.org> <20081001225404.4e973465.akpm@linux-foundation.org> <20081008181223.6954c7b2.randy.dunlap@oracle.com> In-Reply-To: <20081008181223.6954c7b2.randy.dunlap@oracle.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 935 Lines: 22 Randy Dunlap wrote: > On Wed, 1 Oct 2008 22:54:04 -0700 Andrew Morton wrote: > >> This sequence is repeated three or four times and should be pulled out >> into a well-commented function. That comment should explain the logic >> behind the use of these barriers, please. > > and on 2008-OCT-08 Ben Hutchings wrote: > >> All memory barriers need a comment to explain why and what they're doing. Seriously? When a barrier is used, it's generally self-evident what it's doing. The real problem is when a barrier is *not* used. It would probably be more helpful to comment every non-barrier line of code to explain why it's okay if memory operations are getting reordered. -- Chris -- 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/