sched: fix build error in kernel/sched_rt.c when RT_GROUP_SCHED && !SMP

Ingo found a build error in the scheduler when RT_GROUP_SCHED was
enabled, but SMP was not.  This patch rearranges the code such
that it is a little more streamlined and compiles under all permutations
of SMP, UP and RT_GROUP_SCHED.  It was boot tested on my 4-way x86_64
and it still passes preempt-test.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>

1 files changed, 170 insertions, 94 deletions

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 4eda5f795f0..4230b15fe90 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -3,6 +3,40 @@
  * policies)
  */
 
+static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
+{
+        return container_of(rt_se, struct task_struct, rt);
+}
+
+#ifdef CONFIG_RT_GROUP_SCHED
+
+static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
+{
+        return rt_rq->rq;
+}
+
+static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+{
+        return rt_se->rt_rq;
+}
+
+#else /* CONFIG_RT_GROUP_SCHED */
+
+static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
+{
+        return container_of(rt_rq, struct rq, rt);
+}
+
+static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
+{
+        struct task_struct *p = rt_task_of(rt_se);
+        struct rq *rq = task_rq(p);
+
+        return &rq->rt;
+}
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+
 #ifdef CONFIG_SMP
 
 static inline int rt_overloaded(struct rq *rq)
@@ -37,19 +71,35 @@ static inline void rt_clear_overload(struct rq *rq)
         cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
 }
 
-static void update_rt_migration(struct rq *rq)
+static void update_rt_migration(struct rt_rq *rt_rq)
 {
-        if (rq->rt.rt_nr_migratory && (rq->rt.rt_nr_running > 1)) {
-                if (!rq->rt.overloaded) {
-                        rt_set_overload(rq);
-                        rq->rt.overloaded = 1;
+        if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) {
+                if (!rt_rq->overloaded) {
+                        rt_set_overload(rq_of_rt_rq(rt_rq));
+                        rt_rq->overloaded = 1;
                 }
-        } else if (rq->rt.overloaded) {
-                rt_clear_overload(rq);
-                rq->rt.overloaded = 0;
+        } else if (rt_rq->overloaded) {
+                rt_clear_overload(rq_of_rt_rq(rt_rq));
+                rt_rq->overloaded = 0;
         }
 }
 
+static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        if (rt_se->nr_cpus_allowed > 1)
+                rt_rq->rt_nr_migratory++;
+
+        update_rt_migration(rt_rq);
+}
+
+static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        if (rt_se->nr_cpus_allowed > 1)
+                rt_rq->rt_nr_migratory--;
+
+        update_rt_migration(rt_rq);
+}
+
 static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
 {
         plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
@@ -68,14 +118,13 @@ static inline
 void enqueue_pushable_task(struct rq *rq, struct task_struct *p) {}
 static inline
 void dequeue_pushable_task(struct rq *rq, struct task_struct *p) {}
+static inline
+void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
+static inline
+void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
 
 #endif /* CONFIG_SMP */
 
-static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
-{
-        return container_of(rt_se, struct task_struct, rt);
-}
-
 static inline int on_rt_rq(struct sched_rt_entity *rt_se)
 {
         return !list_empty(&rt_se->run_list);
@@ -99,16 +148,6 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 #define for_each_leaf_rt_rq(rt_rq, rq) \
         list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
 
-static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
-{
-        return rt_rq->rq;
-}
-
-static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
-{
-        return rt_se->rt_rq;
-}
-
 #define for_each_sched_rt_entity(rt_se) \
         for (; rt_se; rt_se = rt_se->parent)
 
@@ -196,19 +235,6 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 #define for_each_leaf_rt_rq(rt_rq, rq) \
         for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
 
-static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
-{
-        return container_of(rt_rq, struct rq, rt);
-}
-
-static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
-{
-        struct task_struct *p = rt_task_of(rt_se);
-        struct rq *rq = task_rq(p);
-
-        return &rq->rt;
-}
-
 #define for_each_sched_rt_entity(rt_se) \
         for (; rt_se; rt_se = NULL)
 
@@ -567,7 +593,7 @@ static void update_curr_rt(struct rq *rq)
         }
 }
 
-#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+#if defined CONFIG_SMP
 
 static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu);
 
@@ -580,33 +606,24 @@ static inline int next_prio(struct rq *rq)
         else
                 return MAX_RT_PRIO;
 }
-#endif
 
-static inline
-void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+static void
+inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
 {
-        int prio = rt_se_prio(rt_se);
-#ifdef CONFIG_SMP
         struct rq *rq = rq_of_rt_rq(rt_rq);
-#endif
 
-        WARN_ON(!rt_prio(prio));
-        rt_rq->rt_nr_running++;
-#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
-        if (prio < rt_rq->highest_prio.curr) {
+        if (prio < prev_prio) {
 
                 /*
                  * If the new task is higher in priority than anything on the
-                 * run-queue, we have a new high that must be published to
-                 * the world.  We also know that the previous high becomes
-                 * our next-highest.
+                 * run-queue, we know that the previous high becomes our
+                 * next-highest.
                  */
-                rt_rq->highest_prio.next = rt_rq->highest_prio.curr;
-                rt_rq->highest_prio.curr = prio;
-#ifdef CONFIG_SMP
+                rt_rq->highest_prio.next = prev_prio;
+
                 if (rq->online)
                         cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
-#endif
+
         } else if (prio == rt_rq->highest_prio.curr)
                 /*
                  * If the next task is equal in priority to the highest on
@@ -619,72 +636,131 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
                  * Otherwise, we need to recompute next-highest
                  */
                 rt_rq->highest_prio.next = next_prio(rq);
-#endif
-#ifdef CONFIG_SMP
-        if (rt_se->nr_cpus_allowed > 1)
-                rq->rt.rt_nr_migratory++;
+}
 
-        update_rt_migration(rq);
-#endif
-#ifdef CONFIG_RT_GROUP_SCHED
-        if (rt_se_boosted(rt_se))
-                rt_rq->rt_nr_boosted++;
+static void
+dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
+{
+        struct rq *rq = rq_of_rt_rq(rt_rq);
 
-        if (rt_rq->tg)
-                start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
-#else
-        start_rt_bandwidth(&def_rt_bandwidth);
-#endif
+        if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next))
+                rt_rq->highest_prio.next = next_prio(rq);
+
+        if (rq->online && rt_rq->highest_prio.curr != prev_prio)
+                cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
 }
 
+#else /* CONFIG_SMP */
+
 static inline
-void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
-{
-#ifdef CONFIG_SMP
-        struct rq *rq = rq_of_rt_rq(rt_rq);
-        int highest_prio = rt_rq->highest_prio.curr;
-#endif
+void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
+static inline
+void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
+
+#endif /* CONFIG_SMP */
 
-        WARN_ON(!rt_prio(rt_se_prio(rt_se)));
-        WARN_ON(!rt_rq->rt_nr_running);
-        rt_rq->rt_nr_running--;
 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+static void
+inc_rt_prio(struct rt_rq *rt_rq, int prio)
+{
+        int prev_prio = rt_rq->highest_prio.curr;
+
+        if (prio < prev_prio)
+                rt_rq->highest_prio.curr = prio;
+
+        inc_rt_prio_smp(rt_rq, prio, prev_prio);
+}
+
+static void
+dec_rt_prio(struct rt_rq *rt_rq, int prio)
+{
+        int prev_prio = rt_rq->highest_prio.curr;
+
         if (rt_rq->rt_nr_running) {
-                int prio = rt_se_prio(rt_se);
 
-                WARN_ON(prio < rt_rq->highest_prio.curr);
+                WARN_ON(prio < prev_prio);
 
                 /*
-                 * This may have been our highest or next-highest priority
-                 * task and therefore we may have some recomputation to do
+                 * This may have been our highest task, and therefore
+                 * we may have some recomputation to do
                  */
-                if (prio == rt_rq->highest_prio.curr) {
+                if (prio == prev_prio) {
                         struct rt_prio_array *array = &rt_rq->active;
 
                         rt_rq->highest_prio.curr =
                                 sched_find_first_bit(array->bitmap);
                 }
 
-                if (prio <= rt_rq->highest_prio.next)
-                        rt_rq->highest_prio.next = next_prio(rq);
         } else
                 rt_rq->highest_prio.curr = MAX_RT_PRIO;
-#endif
-#ifdef CONFIG_SMP
-        if (rt_se->nr_cpus_allowed > 1)
-                rq->rt.rt_nr_migratory--;
 
-        if (rq->online && rt_rq->highest_prio.curr != highest_prio)
-                cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
+        dec_rt_prio_smp(rt_rq, prio, prev_prio);
+}
+
+#else
+
+static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
+static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
+
+#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */
 
-        update_rt_migration(rq);
-#endif /* CONFIG_SMP */
 #ifdef CONFIG_RT_GROUP_SCHED
+
+static void
+inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        if (rt_se_boosted(rt_se))
+                rt_rq->rt_nr_boosted++;
+
+        if (rt_rq->tg)
+                start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
+}
+
+static void
+dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
         if (rt_se_boosted(rt_se))
                 rt_rq->rt_nr_boosted--;
 
         WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
-#endif
+}
+
+#else /* CONFIG_RT_GROUP_SCHED */
+
+static void
+inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        start_rt_bandwidth(&def_rt_bandwidth);
+}
+
+static inline
+void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+static inline
+void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        int prio = rt_se_prio(rt_se);
+
+        WARN_ON(!rt_prio(prio));
+        rt_rq->rt_nr_running++;
+
+        inc_rt_prio(rt_rq, prio);
+        inc_rt_migration(rt_se, rt_rq);
+        inc_rt_group(rt_se, rt_rq);
+}
+
+static inline
+void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+{
+        WARN_ON(!rt_prio(rt_se_prio(rt_se)));
+        WARN_ON(!rt_rq->rt_nr_running);
+        rt_rq->rt_nr_running--;
+
+        dec_rt_prio(rt_rq, rt_se_prio(rt_se));
+        dec_rt_migration(rt_se, rt_rq);
+        dec_rt_group(rt_se, rt_rq);
 }
 
 static void __enqueue_rt_entity(struct sched_rt_entity *rt_se)
@@ -1453,7 +1529,7 @@ static void set_cpus_allowed_rt(struct task_struct *p,
                         rq->rt.rt_nr_migratory--;
                 }
 
-                update_rt_migration(rq);
+                update_rt_migration(&rq->rt);
         }
 
         cpumask_copy(&p->cpus_allowed, new_mask);