[PATCH tip/core/rcu 05/10] rcu: Remove "cpu" argument to rcu_preempt_check_callbacks()

From: Paul E. McKenney
Date: Tue Oct 28 2014 - 18:00:43 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

Because rcu_preempt_check_callbacks()'s argument is guaranteed to
always be the current CPU, drop the argument and replace per_cpu()
with __this_cpu_read().

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 2 +-
kernel/rcu/tree.h | 2 +-
kernel/rcu/tree_plugin.h | 8 ++++----
3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 0670ba3a65d3..1af5e2cdcbeb 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2420,7 +2420,7 @@ void rcu_check_callbacks(int user)

rcu_bh_qs();
}
- rcu_preempt_check_callbacks(smp_processor_id());
+ rcu_preempt_check_callbacks();
if (rcu_pending())
invoke_rcu_core();
if (user)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 8e90562010ec..94a26e330c1b 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -561,7 +561,7 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
struct rcu_node *rnp,
struct rcu_data *rdp);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
-static void rcu_preempt_check_callbacks(int cpu);
+static void rcu_preempt_check_callbacks(void);
void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_TREE_PREEMPT_RCU)
static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 09547143628a..7158814b7b4a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -621,7 +621,7 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
*
* Caller must disable hard irqs.
*/
-static void rcu_preempt_check_callbacks(int cpu)
+static void rcu_preempt_check_callbacks(void)
{
struct task_struct *t = current;

@@ -630,8 +630,8 @@ static void rcu_preempt_check_callbacks(int cpu)
return;
}
if (t->rcu_read_lock_nesting > 0 &&
- per_cpu(rcu_preempt_data, cpu).qs_pending &&
- !per_cpu(rcu_preempt_data, cpu).passed_quiesce)
+ __this_cpu_read(rcu_preempt_data.qs_pending) &&
+ !__this_cpu_read(rcu_preempt_data.passed_quiesce))
t->rcu_read_unlock_special.b.need_qs = true;
}

@@ -1017,7 +1017,7 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
* Because preemptible RCU does not exist, it never has any callbacks
* to check.
*/
-static void rcu_preempt_check_callbacks(int cpu)
+static void rcu_preempt_check_callbacks(void)
{
}

--
1.8.1.5

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