UPSTREAM: 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: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
(cherry picked from commit 82d26c36cc68e781400eb4e541f943008208f2d6)

Bug: 258241771
Bug: 222463781
Test: CQ
Change-Id: I4c13f89da735a628a5030ab55a13e338b97da4b8
Signed-off-by: Joel Fernandes <joelaf@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4332176
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Vineeth Pillai <vineethrp@google.com>
(cherry picked from commit bb867be28d6a70b36ff1d6563f794c489072ab7e)
[Minor conflict with 71cf9c983515549999229ba240e61fa20b471dae where it
added a new function in the same location.
Cherry picked from chromeos-5.15 tree. Minor tweaks to commit message
to match Android style]
Signed-off-by: Qais Yousef <qyousef@google.com>

1 files changed, 4 insertions, 17 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1f7f05aa11a5..78deb6a7844f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3168,7 +3168,6 @@ 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:
@@ -3193,7 +3192,6 @@ 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;
 
@@ -3452,9 +3450,7 @@ 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);
@@ -3651,11 +3647,8 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
 	kmemleak_ignore(ptr);
 
 	// 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);
@@ -3730,14 +3723,8 @@ 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);
 	}
 }