The following commit has been merged into the core/rcu branch of tip: Commit-ID: 952371d6fc0bc360d1d5780f86bb355836117ca2 Gitweb: https://git.kernel.org/tip/952371d6fc0bc360d1d5780f86bb355836117ca2 Author: Uladzislau Rezki (Sony) <[email protected]> AuthorDate: Mon, 25 May 2020 23:47:50 +02:00 Committer: Paul E. McKenney <[email protected]> CommitterDate: Mon, 29 Jun 2020 11:59:25 -07:00
rcu/tree: Move kfree_rcu_cpu locking/unlocking to separate functions 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) <[email protected]> Signed-off-by: Uladzislau Rezki (Sony) <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> --- 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 bcdc063..368bdc4 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3035,6 +3035,27 @@ 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. @@ -3260,11 +3281,7 @@ 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. @@ -3295,9 +3312,7 @@ 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);
