Commit 5a4f9059 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Neeraj Upadhyay
Browse files

rcu/nocb: Remove halfway (de-)offloading handling from rcu_core()'s QS reporting 



RCU core can't be running anymore while in the middle of (de-)offloading
since this sort of transition now only applies to offline CPUs.

The locked callback acceleration handling during the transition can
therefore be removed.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Signed-off-by: default avatarNeeraj Upadhyay <neeraj.upadhyay@kernel.org>
parent d2e7f55f

kernel/rcu/tree.c

+0 −13
Original line number Diff line number Diff line
@@ -2386,7 +2386,6 @@ rcu_report_qs_rdp(struct rcu_data *rdp) 
{

	unsigned long flags;

	unsigned long mask;

	bool needacc = false;

	struct rcu_node *rnp;



	WARN_ON_ONCE(rdp->cpu != smp_processor_id());
@@ -2423,23 +2422,11 @@ rcu_report_qs_rdp(struct rcu_data *rdp) 
			 * to return true.  So complain, but don't awaken.

			 */

			WARN_ON_ONCE(rcu_accelerate_cbs(rnp, rdp));

		} else if (!rcu_segcblist_completely_offloaded(&rdp->cblist)) {

			/*

			 * ...but NOCB kthreads may miss or delay callbacks acceleration

			 * if in the middle of a (de-)offloading process.

			 */

			needacc = true;

		}



		rcu_disable_urgency_upon_qs(rdp);

		rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);

		/* ^^^ Released rnp->lock */



		if (needacc) {

			rcu_nocb_lock_irqsave(rdp, flags);

			rcu_accelerate_cbs_unlocked(rnp, rdp);

			rcu_nocb_unlock_irqrestore(rdp, flags);

		}

	}

}