From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757351Ab1ETXOj (ORCPT ); Fri, 20 May 2011 19:14:39 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:35057 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754331Ab1ETXOd (ORCPT ); Fri, 20 May 2011 19:14:33 -0400 Date: Fri, 20 May 2011 16:14:28 -0700 From: "Paul E. McKenney" To: Yinghai Lu Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/rcu] Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" Message-ID: <20110520231428.GN2366@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <4DD6D746.6070107@kernel.org> <20110520224250.GL2366@linux.vnet.ibm.com> <4DD6F4A2.1070401@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DD6F4A2.1070401@kernel.org> 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 Fri, May 20, 2011 at 04:09:22PM -0700, Yinghai Lu wrote: > On 05/20/2011 03:42 PM, Paul E. McKenney wrote: > > On Fri, May 20, 2011 at 02:04:06PM -0700, Yinghai Lu wrote: > >> On 05/19/2011 02:37 PM, tip-bot for Paul E. McKenney wrote: > >>> Commit-ID: 80d02085d99039b3b7f3a73c8896226b0cb1ba07 > >>> Gitweb: http://git.kernel.org/tip/80d02085d99039b3b7f3a73c8896226b0cb1ba07 > >>> Author: Paul E. McKenney > >>> AuthorDate: Thu, 12 May 2011 01:08:07 -0700 > >>> Committer: Ingo Molnar > >>> CommitDate: Thu, 19 May 2011 23:25:29 +0200 > >>> > >>> Revert "rcu: Decrease memory-barrier usage based on semi-formal proof" > >>> > >>> This reverts commit e59fb3120becfb36b22ddb8bd27d065d3cdca499. > >>> > >>> This reversion was due to (extreme) boot-time slowdowns on SPARC seen by > >>> Yinghai Lu and on x86 by Ingo > >>> . > >>> This is a non-trivial reversion due to intervening commits. > >>> > >>> Conflicts: > >>> > >>> Documentation/RCU/trace.txt > >>> kernel/rcutree.c > >>> > >>> Signed-off-by: Ingo Molnar > >>> --- > >>> Documentation/RCU/trace.txt | 17 ++++-- > >>> kernel/rcutree.c | 130 ++++++++++++++++++++++++------------------ > >>> kernel/rcutree.h | 9 ++- > >>> kernel/rcutree_plugin.h | 7 +- > >>> kernel/rcutree_trace.c | 12 ++-- > >>> 5 files changed, 102 insertions(+), 73 deletions(-) > >>> > >> > >> current tip/master that have this reverting and without setting DEBUG_LOCKING_API_SELFTESTS > >> > >> still get delay > >> > >> [ 35.419453] cpu_dev_init done > >> [ 128.981770] memory_dev_init done > >> > >> should take only 3 or 4 seconds. > > > > Thank you for checking this out. > > > > This is with the same configuration you sent earlier? (Other than the > > DEBUG_LOCKING_API_SELFTESTS, of course.) > > > > 8 socket westmere-ex. and compiled with gcc from opensuse 11.3. > > if compile kernel from fedora 14, there will be not delay. Thank you for the info. Could you please send me the .config files from both builds? Thanx, Paul