Release percpu memory after finishing the switch to the atomic mode if only PERCPU_REF_ALLOW_REINIT isn't set.
Signed-off-by: Roman Gushchin <[email protected]> --- include/linux/percpu-refcount.h | 1 + lib/percpu-refcount.c | 13 +++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 0f0240af8520..7aef0abc194a 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -102,6 +102,7 @@ struct percpu_ref { percpu_ref_func_t *release; percpu_ref_func_t *confirm_switch; bool force_atomic:1; + bool allow_reinit:1; struct rcu_head rcu; }; diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index da54318d3b55..47f0aeb136c4 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -69,11 +69,14 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release, return -ENOMEM; ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC; + ref->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT; - if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) + if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) { ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC; - else + ref->allow_reinit = true; + } else { start_count += PERCPU_COUNT_BIAS; + } if (flags & PERCPU_REF_INIT_DEAD) ref->percpu_count_ptr |= __PERCPU_REF_DEAD; @@ -119,6 +122,9 @@ static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu) ref->confirm_switch = NULL; wake_up_all(&percpu_ref_switch_waitq); + if (!ref->allow_reinit) + percpu_ref_exit(ref); + /* drop ref from percpu_ref_switch_to_atomic() */ percpu_ref_put(ref); } @@ -194,6 +200,9 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref) if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC)) return; + if (WARN_ON_ONCE(!ref->allow_reinit)) + return; + atomic_long_add(PERCPU_COUNT_BIAS, &ref->count); /* -- 2.20.1
