From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
The current mapping of smp_processor_id() to a CPU processing Tasks-RCU
callbacks makes some assumptions about layout. This commit therefore
adds a WARN_ON() to check these assumptions.
[ neeraj.upadhyay: Replace nr_cpu_ids with rcu_task_cpu_ids. ]
Signed-off-by: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@xxxxxxxxxx>
---
kernel/rcu/tasks.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 72d564c84499..9fb8bb0afff7 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -357,6 +357,7 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func,
rcu_read_lock();
ideal_cpu = smp_processor_id() >> READ_ONCE(rtp->percpu_enqueue_shift);
chosen_cpu = cpumask_next(ideal_cpu - 1, cpu_possible_mask);
+ WARN_ON_ONCE(chosen_cpu >= rcu_task_cpu_ids);
rtpcp = per_cpu_ptr(rtp->rtpcpu, chosen_cpu);
if (!raw_spin_trylock_rcu_node(rtpcp)) { // irqs already disabled.
raw_spin_lock_rcu_node(rtpcp); // irqs already disabled.
--
2.40.1
