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From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	mingo@kernel.org, jiangshanlai@gmail.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
	fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
	Frederic Weisbecker <frederic@kernel.org>,
	Neeraj Upadhyay <quic_neeraju@quicinc.com>,
	Boqun Feng <boqun.feng@gmail.com>,
	Uladzislau Rezki <urezki@gmail.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 18/18] rcu/nocb: Merge rcu_spawn_cpu_nocb_kthread() and rcu_spawn_one_nocb_kthread()
Date: Wed,  1 Dec 2021 16:29:12 -0800	[thread overview]
Message-ID: <20211202002912.3127710-18-paulmck@kernel.org> (raw)
In-Reply-To: <20211202002848.GA3127439@paulmck-ThinkPad-P17-Gen-1>

From: Frederic Weisbecker <frederic@kernel.org>

The rcu_spawn_one_nocb_kthread() function is called only from
rcu_spawn_cpu_nocb_kthread().  Therefore, inline the former into
the latter, saving a few lines of code.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/tree_nocb.h | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 0c1802ce4764c..eeafb546a7a09 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1233,12 +1233,15 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
  * rcuo CB kthread, spawn it.  Additionally, if the rcuo GP kthread
  * for this CPU's group has not yet been created, spawn it as well.
  */
-static void rcu_spawn_one_nocb_kthread(int cpu)
+static void rcu_spawn_cpu_nocb_kthread(int cpu)
 {
 	struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
 	struct rcu_data *rdp_gp;
 	struct task_struct *t;
 
+	if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup)
+		return;
+
 	/* If there already is an rcuo kthread, then nothing to do. */
 	if (rdp->nocb_cb_kthread)
 		return;
@@ -1262,16 +1265,6 @@ static void rcu_spawn_one_nocb_kthread(int cpu)
 	WRITE_ONCE(rdp->nocb_gp_kthread, rdp_gp->nocb_gp_kthread);
 }
 
-/*
- * If the specified CPU is a no-CBs CPU that does not already have its
- * rcuo kthread, spawn it.
- */
-static void rcu_spawn_cpu_nocb_kthread(int cpu)
-{
-	if (rcu_scheduler_fully_active && rcu_nocb_is_setup)
-		rcu_spawn_one_nocb_kthread(cpu);
-}
-
 /*
  * Once the scheduler is running, spawn rcuo kthreads for all online
  * no-CBs CPUs.  This assumes that the early_initcall()s happen before
-- 
2.31.1.189.g2e36527f23


  parent reply	other threads:[~2021-12-02  0:31 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-02  0:28 [PATCH rcu 0/18] RCU no-CBs CPU updates for v5.17 Paul E. McKenney
2021-12-02  0:28 ` [PATCH rcu 01/18] rcu: Tighten rcu_advance_cbs_nowake() checks Paul E. McKenney
2021-12-02  0:41   ` Frederic Weisbecker
2021-12-02  0:55     ` Paul E. McKenney
2021-12-02  0:28 ` [PATCH rcu 02/18] rcu/nocb: Make local rcu_nocb_lock_irqsave() safe against concurrent deoffloading Paul E. McKenney
2021-12-02  0:28 ` [PATCH rcu 03/18] rcu/nocb: Prepare state machine for a new step Paul E. McKenney
2021-12-02  0:28 ` [PATCH rcu 04/18] rcu/nocb: Invoke rcu_core() at the start of deoffloading Paul E. McKenney
2021-12-02  0:28 ` [PATCH rcu 05/18] rcu/nocb: Make rcu_core() callbacks acceleration preempt-safe Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 06/18] rcu/nocb: Make rcu_core() callbacks acceleration (de-)offloading safe Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 07/18] rcu/nocb: Check a stable offloaded state to manipulate qlen_last_fqs_check Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 08/18] rcu/nocb: Use appropriate rcu_nocb_lock_irqsave() Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 09/18] rcu/nocb: Limit number of softirq callbacks only on softirq Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 10/18] rcu: Fix callbacks processing time limit retaining cond_resched() Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 11/18] rcu: Apply callbacks processing time limit only on softirq Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 12/18] rcu/nocb: Don't invoke local rcu core on callback overload from nocb kthread Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 13/18] rcu/nocb: Remove rcu_node structure from nocb list when de-offloaded Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 14/18] rcu/nocb: Prepare nocb_cb_wait() to start with a non-offloaded rdp Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 15/18] rcu/nocb: Optimize kthreads and rdp initialization Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 16/18] rcu/nocb: Create kthreads on all CPUs if "rcu_nocbs=" or "nohz_full=" are passed Paul E. McKenney
2021-12-02  0:29 ` [PATCH rcu 17/18] rcu/nocb: Allow empty "rcu_nocbs" kernel parameter Paul E. McKenney
2021-12-02  0:29 ` Paul E. McKenney [this message]
2021-12-02  2:03 ` [PATCH rcu 0/18] RCU no-CBs CPU updates for v5.17 Yury Norov
2021-12-02 18:01   ` Paul E. McKenney

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