diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-10-09 10:20:44 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-12-04 10:52:53 -0800 |
| commit | b393e8b33efd2ee08576ceddc10c2b4bfb3b5435 (patch) | |
| tree | 1e0f9f3aa01484a8c815812f14e0f5a4c6890526 /include/linux/percpu-refcount.h | |
| parent | 7088efa9137a15d7d21e3abce73e40c9c8a18d68 (diff) | |
percpu: READ_ONCE() now implies smp_read_barrier_depends()
Because READ_ONCE() now implies smp_read_barrier_depends(), this commit
removes the now-redundant smp_read_barrier_depends() following the
READ_ONCE() in __ref_is_percpu().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Diffstat (limited to 'include/linux/percpu-refcount.h')
| -rw-r--r-- | include/linux/percpu-refcount.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 6658d9ee5257..864d167a1073 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -139,12 +139,12 @@ static inline bool __ref_is_percpu(struct percpu_ref *ref, * when using it as a pointer, __PERCPU_REF_ATOMIC may be set in * between contaminating the pointer value, meaning that * READ_ONCE() is required when fetching it. + * + * The smp_read_barrier_depends() implied by READ_ONCE() pairs + * with smp_store_release() in __percpu_ref_switch_to_percpu(). */ percpu_ptr = READ_ONCE(ref->percpu_count_ptr); - /* paired with smp_store_release() in __percpu_ref_switch_to_percpu() */ - smp_read_barrier_depends(); - /* * Theoretically, the following could test just ATOMIC; however, * then we'd have to mask off DEAD separately as DEAD may be |