diff options
| -rw-r--r-- | include/linux/percpu-refcount.h | 1 | ||||
| -rw-r--r-- | lib/percpu-refcount.c | 17 |
2 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 3a481a49546ef..c13dceb87b60a 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -99,6 +99,7 @@ int __must_check percpu_ref_init(struct percpu_ref *ref, void percpu_ref_exit(struct percpu_ref *ref); void percpu_ref_switch_to_atomic(struct percpu_ref *ref, percpu_ref_func_t *confirm_switch); +void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref); void percpu_ref_switch_to_percpu(struct percpu_ref *ref); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 9ac959ef4cae9..fe03c6d527611 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -260,6 +260,22 @@ void percpu_ref_switch_to_atomic(struct percpu_ref *ref, spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); } +EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic); + +/** + * percpu_ref_switch_to_atomic_sync - switch a percpu_ref to atomic mode + * @ref: percpu_ref to switch to atomic mode + * + * Schedule switching the ref to atomic mode, and wait for the + * switch to complete. Caller must ensure that no other thread + * will switch back to percpu mode. + */ +void percpu_ref_switch_to_atomic_sync(struct percpu_ref *ref) +{ + percpu_ref_switch_to_atomic(ref, NULL); + wait_event(percpu_ref_switch_waitq, !ref->confirm_switch); +} +EXPORT_SYMBOL_GPL(percpu_ref_switch_to_atomic_sync); /** * percpu_ref_switch_to_percpu - switch a percpu_ref to percpu mode @@ -290,6 +306,7 @@ void percpu_ref_switch_to_percpu(struct percpu_ref *ref) spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); } +EXPORT_SYMBOL_GPL(percpu_ref_switch_to_percpu); /** * percpu_ref_kill_and_confirm - drop the initial ref and schedule confirmation |