The following commit has been merged into the core/rcu branch of tip:
Commit-ID: 7ffc9ec8eac196cbd85669a4d7920cd80f186a51
Gitweb:
https://git.kernel.org/tip/7ffc9ec8eac196cbd85669a4d7920cd80f186a51
Author: Paul E. McKenney <paul...@kernel.org>
AuthorDate: Wed, 20 Jan 2021 13:38:08 -08:00
Committer: Paul E. McKenney <paul...@kernel.org>
CommitterDate: Mon, 08 Mar 2021 14:18:07 -08:00
kvfree_rcu: Make krc_this_cpu_unlock() use raw_spin_unlock_irqrestore()
The krc_this_cpu_unlock() function does a raw_spin_unlock() immediately
followed by a local_irq_restore(). This commit saves a line of code by
merging them into a raw_spin_unlock_irqrestore(). This transformation
also reduces scheduling latency because raw_spin_unlock_irqrestore()
responds immediately to a reschedule request. In contrast,
local_irq_restore() does a scheduling-oblivious enabling of interrupts.
Reported-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Signed-off-by: Paul E. McKenney <paul...@kernel.org>
---
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 08b5044..7ee83f3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3229,8 +3229,7 @@ krc_this_cpu_lock(unsigned long *flags)
static inline void
krc_this_cpu_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags)
{
- raw_spin_unlock(&krcp->lock);
- local_irq_restore(flags);
+ raw_spin_unlock_irqrestore(&krcp->lock, flags);
}
static inline struct kvfree_rcu_bulk_data *
