From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760224AbZEFT0r (ORCPT ); Wed, 6 May 2009 15:26:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756163AbZEFT0h (ORCPT ); Wed, 6 May 2009 15:26:37 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:54434 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755638AbZEFT0g (ORCPT ); Wed, 6 May 2009 15:26:36 -0400 Date: Wed, 6 May 2009 12:19:08 -0700 From: Andrew Morton To: paulmck@linux.vnet.ibm.com Cc: mingo@elte.hu, dhowells@redhat.com, linux-kernel@vger.kernel.org, niv@us.ibm.com, dvhltc@us.ibm.com, lethal@linux-sh.org, kernel@wantstofly.org, matthew@wil.cx Subject: Re: [PATCH] v4 RCU: the bloatwatch edition Message-Id: <20090506121908.1fcd3afc.akpm@linux-foundation.org> In-Reply-To: <20090506190216.GE6771@linux.vnet.ibm.com> References: <20090502163423.GA1633@linux.vnet.ibm.com> <20090506112459.5edd0902.akpm@linux-foundation.org> <20090506190216.GE6771@linux.vnet.ibm.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 6 May 2009 12:02:16 -0700 "Paul E. McKenney" wrote: > > > i'm wondering what Andrew thinks - he had objections, right? > > > > > > > More like "concerns". It's unobvious to me that the modest .text > > savings justify the costs of an additional RCU implementation. Where > > those costs include > > > > - additional maintenance work and > > > > - the reduced code reliability which comes from fragmenting the > > tester base. This will mostly affect users of the less popular RCU > > implementations. > > > > But hey, maybe I'm wrong. And maybe I'm right, but we'll merge it anyway ;) > > ;-) > > How about if acceptance of Tiny RCU happens at the same time as Classic > RCU is dropped? That would be a large net decrease in code size and > complexity. It's a bit artificial to link the two actions. Removing something: good. Adding something: bad. good+bad == less good ;)