From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
This commit adds a comment to help explain why the "else" clause of the
in_serving_softirq() "if" statement does not need to enforce a time limit.
The reason is that this "else" clause handles rcuoc kthreads that do not
block handlers for other softirq vectors.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8e880c09ab59..06cc6a6ad819 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2131,6 +2131,8 @@ static void rcu_do_batch(struct rcu_data *rdp)
break;
}
} else {
+ // In rcuoc context, so no worries about depriving
+ // other softirq vectors of CPU cycles.
local_bh_enable();
lockdep_assert_irqs_enabled();
cond_resched_tasks_rcu_qs();
--
2.40.0.rc1.284.g88254d51c5-goog
