sched: clean up the rt priority macros

clean up the rt priority macros, pointed out by Andrew Morton.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 54 insertions, 31 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3e7f189..4dcc61c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -525,31 +525,6 @@ struct signal_struct {
 #define SIGNAL_STOP_CONTINUED	0x00000004 /* SIGCONT since WCONTINUED reap */
 #define SIGNAL_GROUP_EXIT	0x00000008 /* group exit in progress */
 
-
-/*
- * Priority of a process goes from 0..MAX_PRIO-1, valid RT
- * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
- * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
- * values are inverted: lower p->prio value means higher priority.
- *
- * The MAX_USER_RT_PRIO value allows the actual maximum
- * RT priority to be separate from the value exported to
- * user-space.  This allows kernel threads to set their
- * priority to a value higher than any user task. Note:
- * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
- */
-
-#define MAX_USER_RT_PRIO	100
-#define MAX_RT_PRIO		MAX_USER_RT_PRIO
-
-#define MAX_PRIO		(MAX_RT_PRIO + 40)
-
-#define rt_prio(prio)		unlikely((prio) < MAX_RT_PRIO)
-#define rt_task(p)		rt_prio((p)->prio)
-#define batch_task(p)		(unlikely((p)->policy == SCHED_BATCH))
-#define is_rt_policy(p)		((p) != SCHED_NORMAL && (p) != SCHED_BATCH)
-#define has_rt_policy(p)	unlikely(is_rt_policy((p)->policy))
-
 /*
  * Some day this will be a full-fledged user tracking system..
  */
@@ -1164,6 +1139,42 @@ struct task_struct {
 #endif
 };
 
+/*
+ * Priority of a process goes from 0..MAX_PRIO-1, valid RT
+ * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
+ * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
+ * values are inverted: lower p->prio value means higher priority.
+ *
+ * The MAX_USER_RT_PRIO value allows the actual maximum
+ * RT priority to be separate from the value exported to
+ * user-space.  This allows kernel threads to set their
+ * priority to a value higher than any user task. Note:
+ * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
+ */
+
+#define MAX_USER_RT_PRIO	100
+#define MAX_RT_PRIO		MAX_USER_RT_PRIO
+
+#define MAX_PRIO		(MAX_RT_PRIO + 40)
+#define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
+
+static inline int rt_prio(int prio)
+{
+	if (unlikely(prio < MAX_RT_PRIO))
+		return 1;
+	return 0;
+}
+
+static inline int rt_task(struct task_struct *p)
+{
+	return rt_prio(p->prio);
+}
+
+static inline int batch_task(struct task_struct *p)
+{
+	return p->policy == SCHED_BATCH;
+}
+
 static inline pid_t process_group(struct task_struct *tsk)
 {
 	return tsk->signal->pgrp;
diff --git a/kernel/exit.c b/kernel/exit.c
index 6c76992..8fd7acd7 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -290,7 +290,7 @@ static void reparent_to_kthreadd(void)
 	/* Set the exit signal to SIGCHLD so we signal init on exit */
 	current->exit_signal = SIGCHLD;
 
-	if (!has_rt_policy(current) && (task_nice(current) < 0))
+	if (task_nice(current) < 0)
 		set_user_nice(current, 0);
 	/* cpus_allowed? */
 	/* rt_priority? */
diff --git a/kernel/sched.c b/kernel/sched.c
index d9ed927..53c0ee7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -220,6 +220,18 @@ static inline unsigned int task_timeslice(struct task_struct *p)
 	return static_prio_timeslice(p->static_prio);
 }
 
+static inline int rt_policy(int policy)
+{
+	if (unlikely(policy == SCHED_FIFO) || unlikely(policy == SCHED_RR))
+		return 1;
+	return 0;
+}
+
+static inline int task_has_rt_policy(struct task_struct *p)
+{
+	return rt_policy(p->policy);
+}
+
 /*
  * This is the priority-queue data structure of the RT scheduling class:
  */
@@ -698,7 +710,7 @@ static inline int __normal_prio(struct task_struct *p)
 
 static void set_load_weight(struct task_struct *p)
 {
-	if (has_rt_policy(p)) {
+	if (task_has_rt_policy(p)) {
 #ifdef CONFIG_SMP
 		if (p == task_rq(p)->migration_thread)
 			/*
@@ -749,7 +761,7 @@ static inline int normal_prio(struct task_struct *p)
 {
 	int prio;
 
-	if (has_rt_policy(p))
+	if (task_has_rt_policy(p))
 		prio = MAX_RT_PRIO-1 - p->rt_priority;
 	else
 		prio = __normal_prio(p);
@@ -4051,7 +4063,7 @@ void set_user_nice(struct task_struct *p, long nice)
 	 * it wont have any effect on scheduling until the task is
 	 * not SCHED_NORMAL/SCHED_BATCH:
 	 */
-	if (has_rt_policy(p)) {
+	if (task_has_rt_policy(p)) {
 		p->static_prio = NICE_TO_PRIO(nice);
 		goto out_unlock;
 	}
@@ -4240,14 +4252,14 @@ recheck:
 	    (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
 	    (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
 		return -EINVAL;
-	if (is_rt_policy(policy) != (param->sched_priority != 0))
+	if (rt_policy(policy) != (param->sched_priority != 0))
 		return -EINVAL;
 
 	/*
 	 * Allow unprivileged RT tasks to decrease priority:
 	 */
 	if (!capable(CAP_SYS_NICE)) {
-		if (is_rt_policy(policy)) {
+		if (rt_policy(policy)) {
 			unsigned long rlim_rtprio;
 			unsigned long flags;