From: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx> Introduce helpers to lock and unlock per-cpu "kfree_rcu_cpu" structures. That will make kfree_call_rcu() more readable and prevent programming errors. Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/tree.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 519a3f5..edc512e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3017,6 +3017,27 @@ debug_rcu_bhead_unqueue(struct kfree_rcu_bulk_data *bhead) #endif } +static inline struct kfree_rcu_cpu * +krc_this_cpu_lock(unsigned long *flags) +{ + struct kfree_rcu_cpu *krcp; + + local_irq_save(*flags); // For safely calling this_cpu_ptr(). + krcp = this_cpu_ptr(&krc); + if (likely(krcp->initialized)) + raw_spin_lock(&krcp->lock); + + return krcp; +} + +static inline void +krc_this_cpu_unlock(struct kfree_rcu_cpu *krcp, unsigned long flags) +{ + if (likely(krcp->initialized)) + raw_spin_unlock(&krcp->lock); + local_irq_restore(flags); +} + /* * This function is invoked in workqueue context after a grace period. * It frees all the objects queued on ->bhead_free or ->head_free. @@ -3242,11 +3263,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) struct kfree_rcu_cpu *krcp; void *ptr; - local_irq_save(flags); // For safely calling this_cpu_ptr(). - krcp = this_cpu_ptr(&krc); - if (krcp->initialized) - raw_spin_lock(&krcp->lock); - + krcp = krc_this_cpu_lock(&flags); ptr = (void *)head - (unsigned long)func; // Queue the object but don't yet schedule the batch. @@ -3277,9 +3294,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) } unlock_return: - if (krcp->initialized) - raw_spin_unlock(&krcp->lock); - local_irq_restore(flags); + krc_this_cpu_unlock(krcp, flags); } EXPORT_SYMBOL_GPL(kfree_call_rcu); -- 2.9.5