From 6251f9976af7656b6970a8820153f356430f5de2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Sep 2014 13:31:48 -0400 Subject: percpu_ref: minor code and comment updates * Some comments became stale. Updated. * percpu_ref_tryget() unnecessarily initializes @ret. Removed. * A blank line removed from percpu_ref_kill_rcu(). * Explicit function name in a WARN format string replaced with __func__. * WARN_ON() in percpu_ref_reinit() converted to WARN_ON_ONCE(). Signed-off-by: Tejun Heo Reviewed-by: Kent Overstreet --- lib/percpu-refcount.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'lib/percpu-refcount.c') diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 070dab5e7d77..8ef3f5c20df6 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -108,7 +108,6 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) * reaching 0 before we add the percpu counts. But doing it at the same * time is equivalent and saves us atomic operations: */ - atomic_long_add((long)count - PCPU_COUNT_BIAS, &ref->count); WARN_ONCE(atomic_long_read(&ref->count) <= 0, @@ -120,8 +119,8 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) ref->confirm_kill(ref); /* - * Now we're in single atomic_t mode with a consistent refcount, so it's - * safe to drop our initial ref: + * Now we're in single atomic_long_t mode with a consistent + * refcount, so it's safe to drop our initial ref: */ percpu_ref_put(ref); } @@ -134,8 +133,8 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) * Equivalent to percpu_ref_kill() but also schedules kill confirmation if * @confirm_kill is not NULL. @confirm_kill, which may not block, will be * called after @ref is seen as dead from all CPUs - all further - * invocations of percpu_ref_tryget() will fail. See percpu_ref_tryget() - * for more details. + * invocations of percpu_ref_tryget_live() will fail. See + * percpu_ref_tryget_live() for more details. * * Due to the way percpu_ref is implemented, @confirm_kill will be called * after at least one full RCU grace period has passed but this is an @@ -145,8 +144,7 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill) { WARN_ONCE(ref->pcpu_count_ptr & PCPU_REF_DEAD, - "percpu_ref_kill() called more than once on %pf!", - ref->release); + "%s called more than once on %pf!", __func__, ref->release); ref->pcpu_count_ptr |= PCPU_REF_DEAD; ref->confirm_kill = confirm_kill; @@ -172,7 +170,7 @@ void percpu_ref_reinit(struct percpu_ref *ref) int cpu; BUG_ON(!pcpu_count); - WARN_ON(!percpu_ref_is_zero(ref)); + WARN_ON_ONCE(!percpu_ref_is_zero(ref)); atomic_long_set(&ref->count, 1 + PCPU_COUNT_BIAS); -- cgit v1.2.3