[PATCH tip/core/rcu 4/7] kvfree_rcu: Update "monitor_todo" once a batch is started

From: Paul E. McKenney
Date: Tue May 11 2021 - 18:55:22 EST


From: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx>

Before attempting to start a new batch the "monitor_todo" variable is
set to "false" and set back to "true" when a previous RCU batch is still
in progress. This is at best confusing.

Thus change this variable to "false" only when a new batch has been
successfully queued, otherwise, just leave it be.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e86f32d6b8f9..1ae5f88e475f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3442,15 +3442,14 @@ static inline void kfree_rcu_drain_unlock(struct kfree_rcu_cpu *krcp,
unsigned long flags)
{
// Attempt to start a new batch.
- krcp->monitor_todo = false;
if (queue_kfree_rcu_work(krcp)) {
// Success! Our job is done here.
+ krcp->monitor_todo = false;
raw_spin_unlock_irqrestore(&krcp->lock, flags);
return;
}

// Previous RCU batch still in progress, try again later.
- krcp->monitor_todo = true;
schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
raw_spin_unlock_irqrestore(&krcp->lock, flags);
}
--
2.31.1.189.g2e36527f23