From: Zqiang <qiang.zhang@linux.dev>
To: paulmck@kernel.org, frederic@kernel.org,
neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com,
boqun.feng@gmail.com, urezki@gmail.com
Cc: qiang.zhang@linux.dev, rcu@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] rcu-tasks: Remove unnecessary smp_store_release() in cblist_init_generic()
Date: Mon, 5 Jan 2026 09:19:51 +0800 [thread overview]
Message-ID: <20260105011951.72850-1-qiang.zhang@linux.dev> (raw)
The cblist_init_generic() is executed during the CPU early boot
phase due to commit:30ef09635b9e ("rcu-tasks: Initialize callback
lists at rcu_init() time"), at this time, only one boot CPU is
online and the irq is disabled. this commit therefore use routine
assignment replace of smp_store_release() and WRITE_ONCE() in the
cblist_init_generic().
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
---
kernel/rcu/tasks.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 76f952196a29..c736900317cd 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -290,9 +290,9 @@ static void cblist_init_generic(struct rcu_tasks *rtp)
shift = ilog2(rcu_task_cpu_ids / lim);
if (((rcu_task_cpu_ids - 1) >> shift) >= lim)
shift++;
- WRITE_ONCE(rtp->percpu_enqueue_shift, shift);
- WRITE_ONCE(rtp->percpu_dequeue_lim, lim);
- smp_store_release(&rtp->percpu_enqueue_lim, lim);
+ rtp->percpu_enqueue_shift = shift;
+ rtp->percpu_dequeue_lim = lim;
+ rtp->percpu_enqueue_lim = lim;
pr_info("%s: Setting shift to %d and lim to %d rcu_task_cb_adjust=%d rcu_task_cpu_ids=%d.\n",
rtp->name, data_race(rtp->percpu_enqueue_shift), data_race(rtp->percpu_enqueue_lim),
--
2.48.1
next reply other threads:[~2026-01-05 1:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-05 1:19 Zqiang [this message]
2026-01-05 21:34 ` [PATCH v2] rcu-tasks: Remove unnecessary smp_store_release() in cblist_init_generic() Paul E. McKenney
2026-02-25 16:00 ` Joel Fernandes
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