[PATCH tip/core/rcu 14/22] rcu: Remove unneeded __rcu_process_callbacks() argument

Paul E. McKenney
2012-06-22T15:25:23Z

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

With the advent of __this_cpu_ptr(), it is no longer necessary to pass
both the rcu_state and rcu_data structures into __rcu_process_callbacks().
This commit therefore computes the rcu_data pointer from the rcu_state
pointer within __rcu_process_callbacks() so that callers can pass in
only the pointer to the rcu_state structure. This paves the way for
linking the rcu_state structures together and iterating over them.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---
kernel/rcutree.c | 8 ++++----
kernel/rcutree_plugin.h | 3 +--
2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 5c1c6ae..cf7c373 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1785,9 +1785,10 @@ unlock_fqs_ret:
* whom the rdp belongs.
*/
static void
-__rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
+__rcu_process_callbacks(struct rcu_state *rsp)
{
unsigned long flags;
+ struct rcu_data *rdp = __this_cpu_ptr(rsp->rda);

WARN_ON_ONCE(rdp->beenonline == 0);

@@ -1824,9 +1825,8 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
static void rcu_process_callbacks(struct softirq_action *unused)
{
trace_rcu_utilization("Start RCU core");
- __rcu_process_callbacks(&rcu_sched_state,
- &__get_cpu_var(rcu_sched_data));
- __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+ __rcu_process_callbacks(&rcu_sched_state);
+ __rcu_process_callbacks(&rcu_bh_state);
rcu_preempt_process_callbacks();
trace_rcu_utilization("End RCU core");
}
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index a401508..c6e986c 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -687,8 +687,7 @@ static void rcu_preempt_check_callbacks(int cpu)
*/
static void rcu_preempt_process_callbacks(void)
{
- __rcu_process_callbacks(&rcu_preempt_state,
- &__get_cpu_var(rcu_preempt_data));
+ __rcu_process_callbacks(&rcu_preempt_state);
}

#ifdef CONFIG_RCU_BOOST
--
1.7.8