Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757331Ab1DHBYM (ORCPT ); Thu, 7 Apr 2011 21:24:12 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:52965 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1757258Ab1DHBYL convert rfc822-to-8bit (ORCPT ); Thu, 7 Apr 2011 21:24:11 -0400 Message-ID: <4D9E6438.5030206@cn.fujitsu.com> Date: Fri, 08 Apr 2011 09:26:16 +0800 From: Lai Jiangshan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc14 Thunderbird/3.1.4 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: "H. Peter Anvin" , Peter Zijlstra , Michal Marek , Jan Beulich , Ingo Molnar , Alexander van Heukelum , Dipankar Sarma , Andrew Morton , Sam Ravnborg , David Howells , Oleg Nesterov , Roland McGrath , linux-kernel@vger.kernel.org, Thomas Gleixner , Steven Rostedt Subject: Re: [RFC PATCH 4/5] RCU: Add TASK_RCU_OFFSET References: <20110405215450.GK2247@linux.vnet.ibm.com> <20110405230745.GA5972@linux.vnet.ibm.com> <1302077428.2225.1365.camel@twins> <20110406192119.GB2265@linux.vnet.ibm.com> <20110406201350.GA9378@linux.vnet.ibm.com> <1302123970.2207.4.camel@laptop> <4D9CDACB.9050705@linux.intel.com> <20110407003041.GD2265@linux.vnet.ibm.com> <4D9D507F.2040006@cn.fujitsu.com> <20110407154737.GF2262@linux.vnet.ibm.com> <20110407162600.GA24227@linux.vnet.ibm.com> In-Reply-To: <20110407162600.GA24227@linux.vnet.ibm.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-04-08 09:24:50, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-04-08 09:24:51 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3821 Lines: 87 On 04/08/2011 12:26 AM, Paul E. McKenney wrote: > On Thu, Apr 07, 2011 at 08:47:37AM -0700, Paul E. McKenney wrote: >> On Thu, Apr 07, 2011 at 01:49:51PM +0800, Lai Jiangshan wrote: >>> On 04/07/2011 08:30 AM, Paul E. McKenney wrote: >>>> On Wed, Apr 06, 2011 at 02:27:39PM -0700, H. Peter Anvin wrote: >>>>> On 04/06/2011 02:06 PM, Peter Zijlstra wrote: >>>>>> On Wed, 2011-04-06 at 13:13 -0700, Paul E. McKenney wrote: >>>>>>> And the following patch builds correctly for defconfig x86 builds, >>>>>>> while allowing rcupdate.h to see the sched.h definitions as needed >>>>>>> to inline rcu_read_lock() and rcu_read_unlock(). >>>>>>> >>>>>> Looks like an entirely reasonable patch to me ;-) >>>>>> >>>>> >>>>> Quite... a lot better than the original proposal! >>>> >>>> Glad you both like it! >>>> >>>> When I do an allyesconfig build, I do get errors during the "CHECK" >>>> phase, when it is putting things into the usr/include in the build tree. >>>> I believe that this is because I am exposing different header files to >>>> the library-export scripts. The following patch silences some of them, >>>> but I am really out of my depth here. >>>> >>>> Sam, Jan, Michal, help? >>>> >>>> Thanx, Paul >>>> >>>> ------------------------------------------------------------------------ >>>> >>> >>> Easy to split rcupdate.h, hard to resolve the dependence problem. >>> >>> You can apply the next additional patch when you test: >> >> I am sure that you are quite correct. ;-) >> >> I am moving _rcu_read_lock() and _rcu_read_unlock() into >> include/linux/rcutree.h and include/linux/rcutiny.h, and I am sure that >> more pain will ensue. >> >> One thing I don't understand... How does is it helping to group the >> task_struct RCU-related fields into a structure? Is that generating >> better code on your platform due to smaller offsets or something? You don't like task_rcu_struct patch? I think it can make code clearer, and it can also check the code even when CONFIG_PREEMPT_RCU=n. For rcu_read_[un]lock(), it generates the same code, no better, no worse. It is just a cleanup patch, it is helpless for making rcu_read_[un]lock() inline, if you don't like it, I will give up it. >> >> Also, does your patchset address the CHECK warnings? > > I take it back... I applied the following patch on top of my earlier > one, and a defconfig x86 build completed without error. (Though I have > not tested the results of the build.) > > One possible difference -- I did this work on top of a recent Linus > git commit (b2a8b4b81966) rather than on top of my -rcu tree. Also, > I have not yet tried an allyesconfig build, which will no doubt locate > some more problems. > > Thanx, Paul > when defconfig or allyesconfig, CONFIG_PREEMPT=n and CONFIG_TREE_PREEMPT_RCU=n when you make them "y": In file included from include/linux/rcupdate.h:764:0, from include/linux/tracepoint.h:19, from include/linux/module.h:18, from include/linux/crypto.h:21, from arch/x86/kernel/asm-offsets.c:8: include/linux/rcutree.h:50:20: error: static declaration of ‘__rcu_read_lock’ follows non-static declaration include/linux/rcupdate.h:76:13: note: previous declaration of ‘__rcu_read_lock’ was here include/linux/rcutree.h:63:20: error: static declaration of ‘__rcu_read_unlock’ follows non-static declaration include/linux/rcupdate.h:77:13: note: previous declaration of ‘__rcu_read_unlock’ was here make[1]: *** [arch/x86/kernel/asm-offsets.s] Error 1 make: *** [prepare0] Error 2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/