Commit 82d26c36 authored by Joel Fernandes (Google)'s avatar Joel Fernandes (Google) Committed by Paul E. McKenney
Browse files

rcu/kvfree: Remove useless monitor_todo flag 



monitor_todo is not needed as the work struct already tracks
if work is pending. Just use that to know if work is pending
using schedule_delayed_work() helper.

Signed-off-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarNeeraj Upadhyay <quic_neeraju@quicinc.com>
parent e2bb1288

kernel/rcu/tree.c

+16 −17
Original line number Diff line number Diff line
@@ -3216,7 +3216,6 @@ struct kfree_rcu_cpu_work { 
 * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period

 * @lock: Synchronize access to this structure

 * @monitor_work: Promote @head to @head_free after KFREE_DRAIN_JIFFIES

 * @monitor_todo: Tracks whether a @monitor_work delayed work is pending

 * @initialized: The @rcu_work fields have been initialized

 * @count: Number of objects for which GP not started

 * @bkvcache:
@@ -3241,7 +3240,6 @@ struct kfree_rcu_cpu { 
	struct kfree_rcu_cpu_work krw_arr[KFREE_N_BATCHES];

	raw_spinlock_t lock;

	struct delayed_work monitor_work;

	bool monitor_todo;

	bool initialized;

	int count;
@@ -3421,6 +3419,18 @@ static void kfree_rcu_work(struct work_struct *work) 
	}

}



static bool

need_offload_krc(struct kfree_rcu_cpu *krcp)

{

	int i;



	for (i = 0; i < FREE_N_CHANNELS; i++)

		if (krcp->bkvhead[i])

			return true;



	return !!krcp->head;

}



/*

 * This function is invoked after the KFREE_DRAIN_JIFFIES timeout.

 */
@@ -3477,9 +3487,7 @@ static void kfree_rcu_monitor(struct work_struct *work) 
	// of the channels that is still busy we should rearm the

	// work to repeat an attempt. Because previous batches are

	// still in progress.

	if (!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head)

		krcp->monitor_todo = false;

	else

	if (need_offload_krc(krcp))

		schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);



	raw_spin_unlock_irqrestore(&krcp->lock, flags);
@@ -3667,11 +3675,8 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) 
	WRITE_ONCE(krcp->count, krcp->count + 1);



	// Set timer to drain after KFREE_DRAIN_JIFFIES.

	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&

	    !krcp->monitor_todo) {

		krcp->monitor_todo = true;

	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING)

		schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);

	}



unlock_return:

	krc_this_cpu_unlock(krcp, flags);
@@ -3746,14 +3751,8 @@ void __init kfree_rcu_scheduler_running(void) 
		struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);



		raw_spin_lock_irqsave(&krcp->lock, flags);

		if ((!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head) ||

				krcp->monitor_todo) {

			raw_spin_unlock_irqrestore(&krcp->lock, flags);

			continue;

		}

		krcp->monitor_todo = true;

		schedule_delayed_work_on(cpu, &krcp->monitor_work,

					 KFREE_DRAIN_JIFFIES);

		if (need_offload_krc(krcp))

			schedule_delayed_work_on(cpu, &krcp->monitor_work, KFREE_DRAIN_JIFFIES);

		raw_spin_unlock_irqrestore(&krcp->lock, flags);

	}

}