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authorPaul E. McKenney <paulmck@kernel.org>2023-10-11 09:45:54 -0700
committerNeeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>2023-12-12 02:22:47 +0530
commit18966f7b9458d3b19412fe9dfb421ab59401bfe1 (patch)
tree366bb0f9955c056d16d28bfdde2e257eff2eb147 /kernel/rcu/tasks.h
parent98b1cc82c4affc16f5598d4fa14b1858671b2263 (diff)
rcu-tasks: Mark RCU Tasks accesses to current->rcu_tasks_idle_cpu
The task_struct structure's ->rcu_tasks_idle_cpu can be concurrently read and written from the RCU Tasks grace-period kthread and from the CPU on which the task_struct structure's task is running. This commit therefore marks the accesses appropriately. Reported-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
Diffstat (limited to 'kernel/rcu/tasks.h')
-rw-r--r--kernel/rcu/tasks.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index f54d5782eca0..732ad5b39946 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -975,7 +975,7 @@ static void check_holdout_task(struct task_struct *t,
t->rcu_tasks_nvcsw != READ_ONCE(t->nvcsw) ||
!rcu_tasks_is_holdout(t) ||
(IS_ENABLED(CONFIG_NO_HZ_FULL) &&
- !is_idle_task(t) && t->rcu_tasks_idle_cpu >= 0)) {
+ !is_idle_task(t) && READ_ONCE(t->rcu_tasks_idle_cpu) >= 0)) {
WRITE_ONCE(t->rcu_tasks_holdout, false);
list_del_init(&t->rcu_tasks_holdout_list);
put_task_struct(t);
@@ -993,7 +993,7 @@ static void check_holdout_task(struct task_struct *t,
t, ".I"[is_idle_task(t)],
"N."[cpu < 0 || !tick_nohz_full_cpu(cpu)],
t->rcu_tasks_nvcsw, t->nvcsw, t->rcu_tasks_holdout,
- t->rcu_tasks_idle_cpu, cpu);
+ data_race(t->rcu_tasks_idle_cpu), cpu);
sched_show_task(t);
}