From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 457E8C32771 for ; Thu, 18 Aug 2022 01:36:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242580AbiHRBgi (ORCPT ); Wed, 17 Aug 2022 21:36:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238839AbiHRBgf (ORCPT ); Wed, 17 Aug 2022 21:36:35 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ACF4A406A; Wed, 17 Aug 2022 18:36:34 -0700 (PDT) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4M7S7p3XvwzZfkK; Thu, 18 Aug 2022 09:33:10 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 18 Aug 2022 09:36:32 +0800 Received: from [10.174.178.55] (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 18 Aug 2022 09:36:31 +0800 Subject: Re: [PATCH v3 2/2] rcu: Simplify the code logic of rcu_init_nohz() To: kernel test robot , "Paul E . McKenney" , Frederic Weisbecker , "Neeraj Upadhyay" , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , , CC: , References: <20220816124839.1911-3-thunder.leizhen@huawei.com> <202208180940.Jks0rOXz-lkp@intel.com> From: "Leizhen (ThunderTown)" Message-ID: <9b5d69d3-a926-4111-af72-bd3edcc99e6f@huawei.com> Date: Thu, 18 Aug 2022 09:36:30 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <202208180940.Jks0rOXz-lkp@intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/8/18 9:19, kernel test robot wrote: > Hi Zhen, > > Thank you for the patch! Yet something to improve: > > [auto build test ERROR on paulmck-rcu/dev] > [also build test ERROR on linus/master v6.0-rc1 next-20220817] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > url: https://github.com/intel-lab-lkp/linux/commits/Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > base: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev > config: hexagon-randconfig-r041-20220818 (https://download.01.org/0day-ci/archive/20220818/202208180940.Jks0rOXz-lkp@intel.com/config) > compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project aed5e3bea138ce581d682158eb61c27b3cfdd6ec) > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/intel-lab-lkp/linux/commit/a1d5079765918764de3ff6e3e63fa2db7f7c14df > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Zhen-Lei/rcu-nocb-Delete-local-variable-need_rcu_nocb_mask-in-rcu_init_nohz/20220816-205131 > git checkout a1d5079765918764de3ff6e3e63fa2db7f7c14df > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/ > > If you fix the issue, kindly add following tag where applicable > Reported-by: kernel test robot > > All errors (new ones prefixed by >>): > > In file included from kernel/rcu/tree.c:4801: >>> kernel/rcu/tree_nocb.h:1216:10: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers] > cpumask = cpu_possible_mask; > ^ ~~~~~~~~~~~~~~~~~ > 1 error generated. I fixed it yesterday and post v4. Please check for v4. > > > vim +1216 kernel/rcu/tree_nocb.h > > 1208 > 1209 void __init rcu_init_nohz(void) > 1210 { > 1211 int cpu; > 1212 struct rcu_data *rdp; > 1213 struct cpumask *cpumask = NULL; > 1214 > 1215 #if defined(CONFIG_RCU_NOCB_CPU_DEFAULT_ALL) >> 1216 cpumask = cpu_possible_mask; > 1217 #elif defined(CONFIG_NO_HZ_FULL) > 1218 if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask)) > 1219 cpumask = tick_nohz_full_mask; > 1220 #endif > 1221 > 1222 if (cpumask) { > 1223 if (!cpumask_available(rcu_nocb_mask)) { > 1224 if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { > 1225 pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); > 1226 return; > 1227 } > 1228 } > 1229 > 1230 cpumask_or(rcu_nocb_mask, rcu_nocb_mask, cpumask); > 1231 } > 1232 > 1233 if (!cpumask_available(rcu_nocb_mask)) > 1234 return; > 1235 > 1236 if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) { > 1237 pr_info("\tNote: kernel parameter 'rcu_nocbs=', 'nohz_full', or 'isolcpus=' contains nonexistent CPUs.\n"); > 1238 cpumask_and(rcu_nocb_mask, cpu_possible_mask, > 1239 rcu_nocb_mask); > 1240 } > 1241 if (cpumask_empty(rcu_nocb_mask)) > 1242 pr_info("\tOffload RCU callbacks from CPUs: (none).\n"); > 1243 else > 1244 pr_info("\tOffload RCU callbacks from CPUs: %*pbl.\n", > 1245 cpumask_pr_args(rcu_nocb_mask)); > 1246 if (rcu_nocb_poll) > 1247 pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); > 1248 > 1249 for_each_cpu(cpu, rcu_nocb_mask) { > 1250 rdp = per_cpu_ptr(&rcu_data, cpu); > 1251 if (rcu_segcblist_empty(&rdp->cblist)) > 1252 rcu_segcblist_init(&rdp->cblist); > 1253 rcu_segcblist_offload(&rdp->cblist, true); > 1254 rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_CB | SEGCBLIST_KTHREAD_GP); > 1255 rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE); > 1256 } > 1257 rcu_organize_nocb_kthreads(); > 1258 } > 1259 > -- Regards, Zhen Lei