@@ -464,9 +464,17 @@ static void free_mem_alloc(struct bpf_mem_alloc *ma)
{
/* waiting_for_gp lists was drained, but __free_rcu might
* still execute. Wait for it now before we freeing percpu caches.
+ *
+ * rcu_barrier_tasks_trace() doesn't imply synchronize_rcu_tasks_trace(),
+ * but rcu_barrier_tasks_trace() and rcu_barrier() below are only used
+ * to wait for the pending __free_rcu_tasks_trace() and __free_rcu(),
+ * so if call_rcu(head, __free_rcu) is skipped due to
+ * rcu_trace_implies_rcu_gp(), it will be OK to skip rcu_barrier() by
+ * using rcu_trace_implies_rcu_gp() as well.
*/
rcu_barrier_tasks_trace();
- rcu_barrier();
+ if (!rcu_trace_implies_rcu_gp())
+ rcu_barrier();
free_mem_alloc_no_barrier(ma);
}