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

From: KOSAKI Motohiro
Date: Mon Jul 05 2010 - 20:51:43 EST

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@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
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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