From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757341Ab1ETXJz (ORCPT ); Fri, 20 May 2011 19:09:55 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:57587 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754752Ab1ETXJt (ORCPT ); Fri, 20 May 2011 19:09:49 -0400 Message-ID: <4DD6F4A2.1070401@kernel.org> Date: Fri, 20 May 2011 16:09:22 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110414 SUSE/3.1.10 Thunderbird/3.1.10 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com 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" References: <4DD6D746.6070107@kernel.org> <20110520224250.GL2366@linux.vnet.ibm.com> In-Reply-To: <20110520224250.GL2366@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: rtcsinet22.oracle.com [66.248.204.30] X-CT-RefId: str=0001.0A090202.4DD6F4AD.0066,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Thanks Yinghai