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authorPaul E. McKenney <paulmck@kernel.org>2024-08-01 17:34:21 -0700
committerNeeraj Upadhyay <neeraj.upadhyay@kernel.org>2024-08-14 16:48:10 +0530
commit49f49266ec9d61a4d038cb4ddff4417ba793198f (patch)
treefc5c786955ffe428f84154d2369e9a87304bf63e /kernel/rcu
parentfd70e9f1d85f5323096ad313ba73f5fe3d15ea41 (diff)
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rcu/tasks: Check processor-ID assumptions
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@kernel.org> Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tasks.h1
1 files changed, 1 insertions, 0 deletions
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.