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Subject[PATCH 6/6] rcu: Add comment to rcu_do_batch() identifying rcuoc code path
Date
From: "Paul E. McKenney" <paulmck@kernel.org>

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@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
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
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