From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755958AbZDWKEL (ORCPT ); Thu, 23 Apr 2009 06:04:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754199AbZDWKDx (ORCPT ); Thu, 23 Apr 2009 06:03:53 -0400 Received: from gir.skynet.ie ([193.1.99.77]:54623 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756537AbZDWKDv (ORCPT ); Thu, 23 Apr 2009 06:03:51 -0400 Date: Thu, 23 Apr 2009 11:03:48 +0100 From: Mel Gorman To: KOSAKI Motohiro Cc: Dave Hansen , Linux Memory Management List , Christoph Lameter , Nick Piggin , Linux Kernel Mailing List , Lin Ming , Zhang Yanmin , Peter Zijlstra , Pekka Enberg , Andrew Morton Subject: Re: [PATCH 18/22] Use allocation flags as an index to the zone watermark Message-ID: <20090423100348.GA26953@csn.ul.ie> References: <20090422171451.GG15367@csn.ul.ie> <1240422423.10627.96.camel@nimitz> <20090423092350.F6E6.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20090423092350.F6E6.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 23, 2009 at 09:27:15AM +0900, KOSAKI Motohiro wrote: > > On Wed, 2009-04-22 at 18:14 +0100, Mel Gorman wrote: > > > Preference of taste really. When I started a conversion to accessors, it > > > changed something recognised to something new that looked uglier to me. > > > Only one place cares about the union enough to access is via an array so > > > why spread it everywhere. > > > > Personally, I'd say for consistency. Someone looking at both forms > > wouldn't necessarily know that they refer to the same variables unless > > they know about the union. > > for just clalification... > > AFAIK, C language specification don't gurantee point same value. > compiler can insert pad between struct-member and member, but not insert > into array. > Considering that they are the same type for elements and arrays, I didn't think padding would ever be a problem. > However, all gcc version don't do that. I think. but perhaps I missed > some minor gcc release.. > > So, I also like Dave's idea. but it only personal feeling. > The tide is against me on this one :). How about I roll a patch on top of this set that replaces the union by calling all sites? I figure that patch will go through a few revisions before people are happy with the final API. However, as the patch wouldn't change functionality, I'd like to see this series getting wider testing if possible. The replace-union-with-single-array patch can be easily folded in then when it settles. Sound like a plan? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab