[PATCH 2/2] rcu: Remove needless preemption disablement in rcu_all_qs()

From: Frederic Weisbecker
Date: Mon Jul 05 2021 - 19:44:03 EST


The preemption is already disabled when we write rcu_data.rcu_urgent_qs.
We can use __this_cpu_write() directly, although that path is mostly
used when CONFIG_PREEMPT=n.

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Neeraj Upadhyay <neeraju@xxxxxxxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
---
kernel/rcu/tree_plugin.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 27b74352cccf..38b3d01424d7 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -871,7 +871,7 @@ void rcu_all_qs(void)
preempt_enable();
return;
}
- this_cpu_write(rcu_data.rcu_urgent_qs, false);
+ __this_cpu_write(rcu_data.rcu_urgent_qs, false);
if (unlikely(raw_cpu_read(rcu_data.rcu_need_heavy_qs))) {
local_irq_save(flags);
rcu_momentary_dyntick_idle();
--
2.25.1