[PATCH tip/core/rcu 28/52] rcu: Remove rsp parameter from __rcu_process_callbacks()

From: Paul E. McKenney
Date: Wed Aug 29 2018 - 18:43:35 EST


There now is only one rcu_state structure in a given build of the
Linux kernel, so there is no need to pass it as a parameter to RCU's
functions. This commit therefore removes the rsp parameter from
__rcu_process_callbacks(), and also inlines it into rcu_process_callbacks(),
removing the for_each_rcu_flavor() while in the neighborhood.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 26 +++++++-------------------
1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b77e41cbf07c..715ca506b5cd 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2740,17 +2740,19 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
}

/*
- * This does the RCU core processing work for the specified rcu_state
- * and rcu_data structures. This may be called only from the CPU to
- * whom the rdp belongs.
+ * This does the RCU core processing work for the specified rcu_data
+ * structures. This may be called only from the CPU to whom the rdp
+ * belongs.
*/
-static void
-__rcu_process_callbacks(struct rcu_state *rsp)
+static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
{
unsigned long flags;
struct rcu_data *rdp = raw_cpu_ptr(&rcu_data);
struct rcu_node *rnp = rdp->mynode;

+ if (cpu_is_offline(smp_processor_id()))
+ return;
+ trace_rcu_utilization(TPS("Start RCU core"));
WARN_ON_ONCE(!rdp->beenonline);

/* Report any deferred quiescent states if preemption enabled. */
@@ -2779,20 +2781,6 @@ __rcu_process_callbacks(struct rcu_state *rsp)

/* Do any needed deferred wakeups of rcuo kthreads. */
do_nocb_deferred_wakeup(rdp);
-}
-
-/*
- * Do RCU core processing for the current CPU.
- */
-static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
-{
- struct rcu_state *rsp;
-
- if (cpu_is_offline(smp_processor_id()))
- return;
- trace_rcu_utilization(TPS("Start RCU core"));
- for_each_rcu_flavor(rsp)
- __rcu_process_callbacks(rsp);
trace_rcu_utilization(TPS("End RCU core"));
}

--
2.17.1