From: "Paul E. McKenney" <paulmck@kernel.org>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com,
rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH 05/11] rcutorture: Use cpumask_next_wrap() in rcu_torture_preempt()
Date: Wed, 15 Jul 2026 17:25:14 -0700 [thread overview]
Message-ID: <20260716002520.11895-5-paulmck@kernel.org> (raw)
In-Reply-To: <3f56c779-b900-40f9-9a24-6136fb28ddfb@paulmck-laptop>
The rcu_torture_preempt() function uses cpumask_next(), and if that
returns an out-of-bounds result, re-invokes cpumask_next() on -1.
Which is exactly what cpumask_next_wrap() does. This commit therefore
saves a couple of lines by instead using cpumask_next_wrap().
This was reported by metacode when asked to look for opportunities
to use cpumask_next_wrap() in kernel/rcu.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/rcutorture.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 2f510743722fce..64b56ec823c1af 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -4183,9 +4183,7 @@ static int rcu_torture_preempt(void *unused)
// Wait for preempt_interval ms with up to 100us fuzz.
torture_hrtimeout_ms(preempt_interval, 100, &rand);
// Select online CPU.
- cpu = cpumask_next(cpu, cpu_online_mask);
- if (cpu >= nr_cpu_ids)
- cpu = cpumask_next(-1, cpu_online_mask);
+ cpu = cpumask_next_wrap(cpu, cpu_online_mask);
WARN_ON_ONCE(cpu >= nr_cpu_ids);
// Move to that CPU, if can't do so, retry later.
if (torture_sched_setaffinity(current->pid, cpumask_of(cpu), false))
--
2.40.1
next prev parent reply other threads:[~2026-07-16 0:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-16 0:25 [PATCH 0/11] RCU torture-test updates for v7.3 Paul E. McKenney
2026-07-16 0:25 ` [PATCH 01/11] rcutorture: Abstract reader-segment dump into rcu_torture_dump_read_segs() Paul E. McKenney
2026-07-16 0:25 ` [PATCH 02/11] rcutorture: Check for immediate deboosting at reader end Paul E. McKenney
2026-07-16 0:25 ` [PATCH 03/11] rcutorture: Make srcu_read_delay() check for disabled interrupts Paul E. McKenney
2026-07-16 0:25 ` [PATCH 04/11] rcutorture: Test RCU readers from hardware interrupt handlers Paul E. McKenney
2026-07-16 0:25 ` Paul E. McKenney [this message]
2026-07-16 0:25 ` [PATCH 06/11] rcutorture: Use task_state_to_char() for task-state reporting Paul E. McKenney
2026-07-16 0:25 ` [PATCH 07/11] rcutorture: Add nwriters module parameter Paul E. McKenney
2026-07-16 0:25 ` [PATCH 08/11] rcutorture: Add a stall_only " Paul E. McKenney
2026-07-16 0:25 ` [PATCH 09/11] rcutorture: Test RCU Tasks Trace GP implying RCU GP Paul E. McKenney
2026-07-16 0:25 ` [PATCH 10/11] rcutorture: Make RCU Tasks Trace track Reader Batches Paul E. McKenney
2026-07-16 0:25 ` [PATCH 11/11] rcutorture: Use this_cpu_inc() for rcu_torture_count[] and rcu_torture_batch[] Paul E. McKenney
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