[RFC v1 12/14] rcu/kfree: remove useless monitor_todo flag

["Joel Fernandes (Google)" <joel@joelfernandes.org>]

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
delayed_work_pending() helper.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
 kernel/rcu/tree.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 3baf29014f86..3828ac3bf1c4 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3155,7 +3155,6 @@ 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:
@@ -3180,7 +3179,6 @@ 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;
 
@@ -3416,9 +3414,7 @@ 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 (krcp->bkvhead[0] || krcp->bkvhead[1] || krcp->head)
 		schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
 
 	raw_spin_unlock_irqrestore(&krcp->lock, flags);
@@ -3607,10 +3603,8 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
 
 	// Set timer to drain after KFREE_DRAIN_JIFFIES.
 	if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&
-	    !krcp->monitor_todo) {
-		krcp->monitor_todo = true;
+	    !delayed_work_pending(&krcp->monitor_work))
 		schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
-	}
 
 unlock_return:
 	krc_this_cpu_unlock(krcp, flags);
@@ -3685,14 +3679,12 @@ 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;
+		if (krcp->bkvhead[0] || krcp->bkvhead[1] || krcp->head) {
+			if (delayed_work_pending(&krcp->monitor_work)) {
+				schedule_delayed_work_on(cpu, &krcp->monitor_work,
+						KFREE_DRAIN_JIFFIES);
+			}
 		}
-		krcp->monitor_todo = true;
-		schedule_delayed_work_on(cpu, &krcp->monitor_work,
-					 KFREE_DRAIN_JIFFIES);
 		raw_spin_unlock_irqrestore(&krcp->lock, flags);
 	}
 }
-- 
2.36.0.550.gb090851708-goog