Commit f9fc166b authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Paul E. McKenney
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rcu/nocb: Only cancel nocb timer if not polling 



This commit refrains deleting the ->nocb_timer if rcu_nocb is polling
because it should not ever have been queued in the polling case.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 3b2348e2

kernel/rcu/tree_plugin.h

+7 −7
Original line number Diff line number Diff line
@@ -2176,19 +2176,19 @@ static void nocb_gp_wait(struct rcu_data *my_rdp) 
	my_rdp->nocb_gp_gp = needwait_gp;

	my_rdp->nocb_gp_seq = needwait_gp ? wait_gp_seq : 0;

	if (bypass) {

		if (!rcu_nocb_poll) {

			raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags);

			// Avoid race with first bypass CB.

			if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {

				WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);

				del_timer(&my_rdp->nocb_timer);

			}

		if (!rcu_nocb_poll) {

			// At least one child with non-empty ->nocb_bypass, so set

			// timer in order to avoid stranding its callbacks.

			mod_timer(&my_rdp->nocb_bypass_timer, j + 2);

		}

			raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags);

		}

	}

	if (rcu_nocb_poll) {

		/* Polling, so trace if first poll in the series. */

		if (gotcbs)