From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755000Ab0CVP40 (ORCPT ); Mon, 22 Mar 2010 11:56:26 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:50159 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754990Ab0CVP4Y (ORCPT ); Mon, 22 Mar 2010 11:56:24 -0400 Date: Mon, 22 Mar 2010 08:56:16 -0700 From: "Paul E. McKenney" To: Christoph Lameter Cc: Mathieu Desnoyers , Lai Jiangshan , mingo@elte.hu, akpm@linux-foundation.org, dipankar@in.ibm.com, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, Alexey Dobriyan , Peter Zijlstra , linux-kernel@vger.kernel.org, Pekka Enberg Subject: Re: [PATCH] tree/tiny rcu: Add debug RCU head option (v2) Message-ID: <20100322155616.GI2517@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20100319013024.GA28456@Krystal> <4BA2FA01.30102@cn.fujitsu.com> <20100319144434.GA2520@linux.vnet.ibm.com> <20100319165637.GA28123@Krystal> <20100319171105.GB2520@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 22, 2010 at 09:37:55AM -0500, Christoph Lameter wrote: > SLAB overloads "struct slab" with the rcu_head. Its not that critical > there since the metadata allocated for each slab page is larger. SLUB does > not have such a per slab page metadata structure and limits its metadata > to what is available in the page struct. Thank you for the info! FWIW, Mathieu is now using debug objects, which permits him to keep rcu_head the same size. Thanx, Paul