Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [PATCH 1/4] percpu-refcount: move zeroing of percpu part into percpu_ref_switch_to_atomic_rcu | Date | Tue, 18 Sep 2018 18:19:43 +0800 |
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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@kernel.org> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: linux-block@vger.kernel.org Signed-off-by: Ming Lei <ming.lei@redhat.com> --- 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
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