Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758813AbZFWJNb (ORCPT ); Tue, 23 Jun 2009 05:13:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754454AbZFWJNE (ORCPT ); Tue, 23 Jun 2009 05:13:04 -0400 Received: from mx2.redhat.com ([66.187.237.31]:37895 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752463AbZFWJNB (ORCPT ); Tue, 23 Jun 2009 05:13:01 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20090623042442.GA15630@linux.vnet.ibm.com> References: <20090623042442.GA15630@linux.vnet.ibm.com> To: paulmck@linux.vnet.ibm.com Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@linux-foundation.org, niv@us.ibm.com, dvhltc@us.ibm.com, lethal@linux-sh.org, kernel@wantstofly.org, matthew@wil.cx Subject: Re: [PATCH] v5 RCU: the bloatwatch edition Date: Tue, 23 Jun 2009 10:12:38 +0100 Message-ID: <28711.1245748358@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2262 Lines: 64 Paul E. McKenney wrote: > This patch is a version of RCU designed for (!SMP && EMBEDDED) > provided as a proof of concept of a small-footprint RCU implementation. > In particular, the implementation of synchronize_rcu() is extremely > lightweight and high performance. It passes rcutorture testing in each > of the four relevant configurations (combinations of NO_HZ and PREEMPT) > on x86. This saves 1263 bytes compared to Classic RCU, and more than > three kilobytes compared to Hierarchical RCU (updated to 2.6.30): On FRV: CONFIG_CLASSIC_RCU=y text data bss dec hex filename 884 32 20 936 3a8 kernel/rcupdate.o 2616 184 0 2800 af0 kernel/rcuclassic.o CONFIG_TREE_RCU=y text data bss dec hex filename 884 32 20 936 3a8 kernel/rcupdate.o 4068 384 0 4452 1164 kernel/rcutree.o CONFIG_TINY_RCU=y text data bss dec hex filename 836 32 20 888 378 kernel/rcupdate.o 816 24 0 840 348 kernel/rcutiny.o On MN10300: CONFIG_CLASSIC_RCU=y text data bss dec hex filename 900 28 48 976 3d0 kernel/rcupdate.o 1777 184 0 1961 7a9 kernel/rcuclassic.o CONFIG_TREE_RCU=y text data bss dec hex filename 900 28 48 976 3d0 kernel/rcupdate.o 2733 384 0 3117 c2d kernel/rcutree.o CONFIG_PREEMPT_RCU=y text data bss dec hex filename 961 28 48 1037 40d kernel/rcupdate.o 3314 128 8 3450 d7a kernel/rcupreempt.o CONFIG_TINY_RCU=y text data bss dec hex filename 865 28 48 941 3ad kernel/rcupdate.o 500 24 0 524 20c kernel/rcutiny.o > Signed-off-by: Paul E. McKenney Acked-by: David Howells