The following commit has been merged into the core/rcu branch of tip:
Commit-ID: f9fc166b790bd214083035d865653133b8a963d1
Gitweb: https://git.kernel.org/tip/f9fc166b790bd214083035d865653133b8a963d1
Author: Frederic Weisbecker <frederic@xxxxxxxxxx>
AuthorDate: Tue, 23 Feb 2021 01:10:09 +01:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Wed, 12 May 2021 12:10:23 -07:00
rcu/nocb: Only cancel nocb timer if not polling
This commit refrains deleting the ->nocb_timer if rcu_nocb is polling
because it should not ever have been queued in the polling case.
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Cc: Neeraj Upadhyay <neeraju@xxxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree_plugin.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 4253a0e..db28e31 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2176,18 +2176,18 @@ static void nocb_gp_wait(struct rcu_data *my_rdp)
my_rdp->nocb_gp_gp = needwait_gp;
my_rdp->nocb_gp_seq = needwait_gp ? wait_gp_seq : 0;
if (bypass) {
- raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags);
- // Avoid race with first bypass CB.
- if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
- WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
- del_timer(&my_rdp->nocb_timer);
- }
if (!rcu_nocb_poll) {
+ raw_spin_lock_irqsave(&my_rdp->nocb_gp_lock, flags);
+ // Avoid race with first bypass CB.
+ if (my_rdp->nocb_defer_wakeup > RCU_NOCB_WAKE_NOT) {
+ WRITE_ONCE(my_rdp->nocb_defer_wakeup, RCU_NOCB_WAKE_NOT);
+ del_timer(&my_rdp->nocb_timer);
+ }
// At least one child with non-empty ->nocb_bypass, so set
// timer in order to avoid stranding its callbacks.
mod_timer(&my_rdp->nocb_bypass_timer, j + 2);
+ raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags);
}
- raw_spin_unlock_irqrestore(&my_rdp->nocb_gp_lock, flags);
}
if (rcu_nocb_poll) {
/* Polling, so trace if first poll in the series. */
|