From: Zqiang <qiang.zhang@linux.dev>
To: paulmck@kernel.org, frederic@kernel.org,
neeraj.upadhyay@kernel.org, joelagnelf@nvidia.com
Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, qiang.zhang@linux.dev
Subject: [PATCH] rcu-tasks: Remove unnecessary smp_store operations in the cblist_init_generic()
Date: Sun, 14 Dec 2025 10:49:04 +0800 [thread overview]
Message-ID: <20251214024904.121128-1-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. this commit therefore use WRITE_ONCE() to replace the
smp_store_release() to assigning rtp->percpu_enqueue_lim in the
cblist_init_generic().
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
---
kernel/rcu/tasks.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 76f952196a29..f763f60d5e50 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -292,7 +292,7 @@ static void cblist_init_generic(struct rcu_tasks *rtp)
shift++;
WRITE_ONCE(rtp->percpu_enqueue_shift, shift);
WRITE_ONCE(rtp->percpu_dequeue_lim, lim);
- smp_store_release(&rtp->percpu_enqueue_lim, lim);
+ WRITE_ONCE(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:[~2025-12-14 2:49 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-14 2:49 Zqiang [this message]
2025-12-25 18:57 ` [PATCH] rcu-tasks: Remove unnecessary smp_store operations in the cblist_init_generic() Paul E. McKenney
2025-12-31 7:55 ` Zqiang
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