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 0A077C433EF for ; Wed, 16 Feb 2022 15:42:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235624AbiBPPmj (ORCPT ); Wed, 16 Feb 2022 10:42:39 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235585AbiBPPmb (ORCPT ); Wed, 16 Feb 2022 10:42:31 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7C559A9A6 for ; Wed, 16 Feb 2022 07:42:18 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2FC2661899 for ; Wed, 16 Feb 2022 15:42:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CEFCC340F1; Wed, 16 Feb 2022 15:42:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645026137; bh=8+SlU7r8WAJmX5jNCV3E4luagGnB16N6dk5c/+4swoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kwQZ+eevSUosmgfHtAamiyR/6lH+C3ob1Qu9qWJ7biBuyPRRZPc4qzw5e0chgMIWS De3AV1NclV9Chzz7Gs91GF5H0B0jsopNVpYWLXOrzRLGPKG1Q6ZYSqLYxlh3nTH9WO 13KqxiqwHvmqDOnN4kewIMdkHnD3QyJSYKsn7giHfKR+SD0x4sLFpNniUbszXM4x9x xVsE9ShLmjOQ/Jf2kkI0AduomBe430g5P66nPUCRw7r/sZyJ3WRY42Og7ZvMNaB/7b tHEUQ5Cson1b7PKlp28DHueYrx3BdCBJd1pik8PORAo9M7xNt+MeA0BNCeXcxR95MM dTOWYPZvaw/qw== From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Frederic Weisbecker , Neeraj Upadhyay , Boqun Feng , Uladzislau Rezki , Joel Fernandes Subject: [PATCH 2/5] rcu/nocb: Move rcu_nocb_is_setup to rcu_state Date: Wed, 16 Feb 2022 16:42:05 +0100 Message-Id: <20220216154208.696069-3-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220216154208.696069-1-frederic@kernel.org> References: <20220216154208.696069-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to avoid scattering the global RCU states, move the RCU nocb initialization witness within rcu_state. Reported-by: Paul E. McKenney Cc: Neeraj Upadhyay Cc: Uladzislau Rezki Cc: Joel Fernandes Cc: Boqun Feng Signed-off-by: Frederic Weisbecker --- kernel/rcu/tree.h | 1 + kernel/rcu/tree_nocb.h | 15 ++++++--------- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 19fc9acce3ce..735fc410d76a 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -368,6 +368,7 @@ struct rcu_state { arch_spinlock_t ofl_lock ____cacheline_internodealigned_in_smp; /* Synchronize offline with */ /* GP pre-initialization. */ + int nocb_is_setup; /* nocb is setup from boot */ }; /* Values for rcu_state structure's gp_flags field. */ diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h index 02e1d05a11fc..494e65445773 100644 --- a/kernel/rcu/tree_nocb.h +++ b/kernel/rcu/tree_nocb.h @@ -60,9 +60,6 @@ static inline bool rcu_current_is_nocb_kthread(struct rcu_data *rdp) * Parse the boot-time rcu_nocb_mask CPU list from the kernel parameters. * If the list is invalid, a warning is emitted and all CPUs are offloaded. */ - -static bool rcu_nocb_is_setup; - static int __init rcu_nocb_setup(char *str) { alloc_bootmem_cpumask_var(&rcu_nocb_mask); @@ -72,7 +69,7 @@ static int __init rcu_nocb_setup(char *str) cpumask_setall(rcu_nocb_mask); } } - rcu_nocb_is_setup = true; + rcu_state.nocb_is_setup = true; return 1; } __setup("rcu_nocbs", rcu_nocb_setup); @@ -1165,17 +1162,17 @@ void __init rcu_init_nohz(void) need_rcu_nocb_mask = true; #endif /* #if defined(CONFIG_NO_HZ_FULL) */ - if (need_rcu_nocb_mask) { + if (rcu_state.nocb_is_setup) { if (!cpumask_available(rcu_nocb_mask)) { if (!zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL)) { pr_info("rcu_nocb_mask allocation failed, callback offloading disabled.\n"); return; } } - rcu_nocb_is_setup = true; + rcu_state.nocb_is_setup = true; } - if (!rcu_nocb_is_setup) + if (!rcu_state.nocb_is_setup) return; #if defined(CONFIG_NO_HZ_FULL) @@ -1233,7 +1230,7 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu) struct task_struct *t; struct sched_param sp; - if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup) + if (!rcu_scheduler_fully_active || !rcu_state.nocb_is_setup) return; /* If there already is an rcuo kthread, then nothing to do. */ @@ -1279,7 +1276,7 @@ static void __init rcu_spawn_nocb_kthreads(void) { int cpu; - if (rcu_nocb_is_setup) { + if (rcu_state.nocb_is_setup) { for_each_online_cpu(cpu) rcu_spawn_cpu_nocb_kthread(cpu); } -- 2.25.1