rcu: Remove "cpu" argument to rcu_note_context_switch()
The "cpu" argument to rcu_note_context_switch() is always the current
CPU, so drop it. This in turn allows the "cpu" argument to
rcu_preempt_note_context_switch() to be removed, which allows the sole
use of "cpu" in both functions to be replaced with a this_cpu_ptr().
Again, the anticipated cross-CPU uses of these functions has been
replaced by NO_HZ_FULL.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 38cc5b1..0e53662 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -78,7 +78,7 @@
call_rcu(head, func);
}
-static inline void rcu_note_context_switch(int cpu)
+static inline void rcu_note_context_switch(void)
{
rcu_sched_qs();
}
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 3e2f5d4..7b5484d 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -30,7 +30,7 @@
#ifndef __LINUX_RCUTREE_H
#define __LINUX_RCUTREE_H
-void rcu_note_context_switch(int cpu);
+void rcu_note_context_switch(void);
#ifndef CONFIG_RCU_NOCB_CPU_ALL
int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
@@ -43,7 +43,7 @@
*/
static inline void rcu_virt_note_context_switch(int cpu)
{
- rcu_note_context_switch(cpu);
+ rcu_note_context_switch();
}
void synchronize_rcu_bh(void);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1af5e2c..b591f14 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -286,11 +286,11 @@
* and requires special handling for preemptible RCU.
* The caller must have disabled preemption.
*/
-void rcu_note_context_switch(int cpu)
+void rcu_note_context_switch(void)
{
trace_rcu_utilization(TPS("Start context switch"));
rcu_sched_qs();
- rcu_preempt_note_context_switch(cpu);
+ rcu_preempt_note_context_switch();
if (unlikely(raw_cpu_read(rcu_sched_qs_mask)))
rcu_momentary_dyntick_idle();
trace_rcu_utilization(TPS("End context switch"));
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 94a26e3..238ac39 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -547,7 +547,7 @@
/* Forward declarations for rcutree_plugin.h */
static void rcu_bootup_announce(void);
long rcu_batches_completed(void);
-static void rcu_preempt_note_context_switch(int cpu);
+static void rcu_preempt_note_context_switch(void);
static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp);
#ifdef CONFIG_HOTPLUG_CPU
static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7158814..495d4cc 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -156,7 +156,7 @@
*
* Caller must disable preemption.
*/
-static void rcu_preempt_note_context_switch(int cpu)
+static void rcu_preempt_note_context_switch(void)
{
struct task_struct *t = current;
unsigned long flags;
@@ -167,7 +167,7 @@
!t->rcu_read_unlock_special.b.blocked) {
/* Possibly blocking in an RCU read-side critical section. */
- rdp = per_cpu_ptr(rcu_preempt_state.rda, cpu);
+ rdp = this_cpu_ptr(rcu_preempt_state.rda);
rnp = rdp->mynode;
raw_spin_lock_irqsave(&rnp->lock, flags);
smp_mb__after_unlock_lock();
@@ -945,7 +945,7 @@
* Because preemptible RCU does not exist, we never have to check for
* CPUs being in quiescent states.
*/
-static void rcu_preempt_note_context_switch(int cpu)
+static void rcu_preempt_note_context_switch(void)
{
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4499950..cc18694 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2802,7 +2802,7 @@
preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
- rcu_note_context_switch(cpu);
+ rcu_note_context_switch();
prev = rq->curr;
schedule_debug(prev);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 0699add..501baa9 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -656,7 +656,7 @@
* in the task stack here.
*/
__do_softirq();
- rcu_note_context_switch(cpu);
+ rcu_note_context_switch();
local_irq_enable();
cond_resched();
return;