[PATCH 2/2] sched: make sched_param arugment static variables in some sched_setscheduler() caller

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Andrew Morton pointed out almost sched_setscheduler() caller are
using fixed parameter and it can be converted static. it reduce
runtume memory waste a bit.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
 include/linux/sched.h         |    5 +++--
 kernel/irq/manage.c           |    4 +++-
 kernel/kthread.c              |    2 +-
 kernel/sched.c                |    6 +++---
 kernel/softirq.c              |    4 +++-
 kernel/stop_machine.c         |    2 +-
 kernel/trace/trace_selftest.c |    2 +-
 kernel/watchdog.c             |    2 +-
 kernel/workqueue.c            |    2 +-
 9 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index cfcd13e..97b7fe3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1917,9 +1917,10 @@ extern int task_nice(const struct task_struct *p);
 extern int can_nice(const struct task_struct *p, const int nice);
 extern int task_curr(const struct task_struct *p);
 extern int idle_cpu(int cpu);
-extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);
+extern int sched_setscheduler(struct task_struct *, int,
+			      const struct sched_param *);
 extern int sched_setscheduler_nocheck(struct task_struct *, int,
-				      struct sched_param *);
+				      const struct sched_param *);
 extern struct task_struct *idle_task(int cpu);
 extern struct task_struct *curr_task(int cpu);
 extern void set_curr_task(int cpu, struct task_struct *p);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 3164ba7..ce1dbb8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -569,7 +569,9 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
  */
 static int irq_thread(void *data)
 {
-	struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
+	static struct sched_param param = {
+		.sched_priority = MAX_USER_RT_PRIO/2,
+	};
 	struct irqaction *action = data;
 	struct irq_desc *desc = irq_to_desc(action->irq);
 	int wake, oneshot = desc->status & IRQ_ONESHOT;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 83911c7..3b55a26 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -131,7 +131,7 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
 	wait_for_completion(&create.done);
 
 	if (!IS_ERR(create.result)) {
-		struct sched_param param = { .sched_priority = 0 };
+		static struct sched_param param = { .sched_priority = 0 };
 		va_list args;
 
 		va_start(args, namefmt);
diff --git a/kernel/sched.c b/kernel/sched.c
index 18faf4d..8f2f4b4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4396,7 +4396,7 @@ static bool check_same_owner(struct task_struct *p)
 }
 
 static int __sched_setscheduler(struct task_struct *p, int policy,
-				struct sched_param *param, bool user)
+				const struct sched_param *param, bool user)
 {
 	int retval, oldprio, oldpolicy = -1, on_rq, running;
 	unsigned long flags;
@@ -4540,7 +4540,7 @@ recheck:
  * NOTE that the task may be already dead.
  */
 int sched_setscheduler(struct task_struct *p, int policy,
-		       struct sched_param *param)
+		       const struct sched_param *param)
 {
 	return __sched_setscheduler(p, policy, param, true);
 }
@@ -4558,7 +4558,7 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
  * but our caller might not have that capability.
  */
 int sched_setscheduler_nocheck(struct task_struct *p, int policy,
-			       struct sched_param *param)
+			       const struct sched_param *param)
 {
 	return __sched_setscheduler(p, policy, param, false);
 }
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 07b4f1b..be3ec11 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -827,7 +827,9 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb,
 			     cpumask_any(cpu_online_mask));
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN: {
-		struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+		static struct sched_param param = {
+			.sched_priority = MAX_RT_PRIO-1
+		};
 
 		p = per_cpu(ksoftirqd, hotcpu);
 		per_cpu(ksoftirqd, hotcpu) = NULL;
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 70f8d90..da9bb42 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -291,7 +291,7 @@ repeat:
 static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
 					   unsigned long action, void *hcpu)
 {
-	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+	static struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
 	unsigned int cpu = (unsigned long)hcpu;
 	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
 	struct task_struct *p;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 250e7f9..d2ebe6e 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -560,7 +560,7 @@ trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
 static int trace_wakeup_test_thread(void *data)
 {
 	/* Make this a RT thread, doesn't need to be too high */
-	struct sched_param param = { .sched_priority = 5 };
+	static struct sched_param param = { .sched_priority = 5 };
 	struct completion *x = data;
 
 	sched_setscheduler(current, SCHED_FIFO, &param);
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 91b0b26..95d8463 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -310,7 +310,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
  */
 static int watchdog(void *unused)
 {
-	struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+	static struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 	struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
 
 	sched_setscheduler(current, SCHED_FIFO, &param);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 327d2de..036939a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -947,7 +947,7 @@ init_cpu_workqueue(struct workqueue_struct *wq, int cpu)
 
 static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
 {
-	struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+	static struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 	struct workqueue_struct *wq = cwq->wq;
 	const char *fmt = is_wq_single_threaded(wq) ? "%s" : "%s/%d";
 	struct task_struct *p;
-- 
1.6.5.2



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