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[07/13] rcu/nocb: Directly call __wake_nocb_gp() from bypass timer

Message ID 20210223001011.127063-8-frederic@kernel.org
State Accepted
Commit c7ef7500a891432a3bb2b036f535bfdf58aa3605
Headers show
Series rcu/nocb updates v2 | expand

Commit Message

Frederic Weisbecker Feb. 23, 2021, 12:10 a.m. UTC
The bypass timer calls __call_rcu_nocb_wake() instead of directly
calling __wake_nocb_gp(). The only difference here is that
rdp->qlen_last_fqs_check gets overriden. But resetting the deferred
force quiescent state base shouldn't be relevant for that timer. In fact
the bypass queue in concern can be for any rdp from the group and not
necessarily the rdp leader on which the bypass timer is attached.

Therefore we can simply call directly __wake_nocb_gp(). This way we
don't even need to lock the nocb_lock.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
---
 kernel/rcu/tree_plugin.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 847636d3e93d..c80b214a86bb 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2025,9 +2025,10 @@  static void do_nocb_bypass_wakeup_timer(struct timer_list *t)
 	struct rcu_data *rdp = from_timer(rdp, t, nocb_bypass_timer);
 
 	trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("Timer"));
-	rcu_nocb_lock_irqsave(rdp, flags);
+
+	raw_spin_lock_irqsave(&rdp->nocb_gp_lock, flags);
 	smp_mb__after_spinlock(); /* Timer expire before wakeup. */
-	__call_rcu_nocb_wake(rdp, true, flags);
+	__wake_nocb_gp(rdp, rdp, false, flags);
 }
 
 /*