The percpu parts are added to atomic part in percpu_ref_switch_to_atomic_rcu(),
so it is readable & reasonable to clear them there.
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: linux-block@xxxxxxxxxxxxxxx
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
lib/percpu-refcount.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 9f96fa7bc000..a220b717f6bb 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -130,8 +130,10 @@ static void percpu_ref_switch_to_atomic_rcu(struct rcu_head *rcu)
unsigned long count = 0;
int cpu;
- for_each_possible_cpu(cpu)
+ for_each_possible_cpu(cpu) {
count += *per_cpu_ptr(percpu_count, cpu);
+ *per_cpu_ptr(percpu_count, cpu) = 0;
+ }
pr_debug("global %ld percpu %ld",
atomic_long_read(&ref->count), (long)count);
@@ -187,7 +189,6 @@ static void __percpu_ref_switch_to_atomic(struct percpu_ref *ref,
static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
{
unsigned long __percpu *percpu_count = percpu_count_ptr(ref);
- int cpu;
BUG_ON(!percpu_count);
@@ -202,9 +203,6 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
* zeroing is visible to all percpu accesses which can see the
* following __PERCPU_REF_ATOMIC clearing.
*/
- for_each_possible_cpu(cpu)
- *per_cpu_ptr(percpu_count, cpu) = 0;
-
smp_store_release(&ref->percpu_count_ptr,
ref->percpu_count_ptr & ~__PERCPU_REF_ATOMIC);
}
--
2.9.5
