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McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Josh Triplett , Boqun Feng , Uladzislau Rezki , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Davidlohr Bueso , rcu@vger.kernel.org, Joel Fernandes Subject: [PATCH v4 1/8] rcu: introduce rcu_defer_qs_clear() helper Date: Thu, 25 Jun 2026 20:42:54 -0400 Message-Id: <20260626004301.1632168-2-joelagnelf@nvidia.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260626004301.1632168-1-joelagnelf@nvidia.com> References: <20260626004301.1632168-1-joelagnelf@nvidia.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: MN2PR03CA0025.namprd03.prod.outlook.com (2603:10b6:208:23a::30) To DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB6486:EE_|DM4PR12MB6207:EE_ X-MS-Office365-Filtering-Correlation-Id: 76e5b57d-e837-4099-78f8-08ded31be3d6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|23010399003|376014|7416014|56012099006|11063799006|22082099003|18002099003; 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Both write the IDLE value directly. Introduce a single inline helper rcu_defer_qs_clear() in tree.h and route both sites through it. This becomes the single PENDING->IDLE transition point for upcoming work. Signed-off-by: Joel Fernandes --- kernel/rcu/tree.h | 5 +++++ kernel/rcu/tree_plugin.h | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 750b98f0c6bc..dc03231b2d46 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -311,6 +311,11 @@ struct rcu_data { int cpu; }; +static inline void rcu_defer_qs_clear(struct rcu_data *rdp) +{ + WRITE_ONCE(rdp->defer_qs_pending, DEFER_QS_IDLE); +} + /* Values for nocb_defer_wakeup field in struct rcu_data. */ #define RCU_NOCB_WAKE_NOT 0 #define RCU_NOCB_WAKE_BYPASS 1 diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index c22f033e0136..7555022bf38a 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -582,7 +582,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) rdp = this_cpu_ptr(&rcu_data); if (rdp->defer_qs_pending == DEFER_QS_PENDING) - rdp->defer_qs_pending = DEFER_QS_IDLE; + rcu_defer_qs_clear(rdp); /* * If RCU core is waiting for this CPU to exit its critical section, @@ -725,7 +725,7 @@ static void rcu_preempt_deferred_qs_handler(struct irq_work *iwp) * 5. Deferred QS reporting does not happen. */ if (rcu_preempt_depth() > 0) - WRITE_ONCE(rdp->defer_qs_pending, DEFER_QS_IDLE); + rcu_defer_qs_clear(rdp); } /* -- 2.34.1