[git pull] fixes for tip/sched/rt

From: Gregory Haskins
Date: Mon Jan 12 2009 - 14:31:20 EST


The following changes since commit 0a6d4e1dc9154c4376358663d74060d1e33d203e:
Ingo Molnar (1):
Merge branch 'sched/latest' of git://git.kernel.org/.../ghaskins/linux-2.6-hacks into sched/rt

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks.git sched/latest

Gregory Haskins (1):
sched: fix build error in kernel/sched_rt.c when RT_GROUP_SCHED && !SMP

kernel/sched.c | 4 +
kernel/sched_rt.c | 223 +++++++++++++++++++++++++++++++----------------------
2 files changed, 136 insertions(+), 91 deletions(-)

---------------------------

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@xxxxxxxxxx>
---

kernel/sched.c | 4 +
kernel/sched_rt.c | 223 +++++++++++++++++++++++++++++++----------------------
2 files changed, 136 insertions(+), 91 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index dd1a146..2b703f1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -466,7 +466,9 @@ struct rt_rq {
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
+#ifdef CONFIG_SMP
int next; /* next highest */
+#endif
} highest_prio;
#endif
#ifdef CONFIG_SMP
@@ -8267,8 +8269,10 @@ static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)

#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
rt_rq->highest_prio.curr = MAX_RT_PRIO;
+#ifdef CONFIG_SMP
rt_rq->highest_prio.next = MAX_RT_PRIO;
#endif
+#endif
#ifdef CONFIG_SMP
rt_rq->rt_nr_migratory = 0;
rt_rq->overloaded = 0;
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 18c7b5b..c9bcdc5 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);
@@ -66,14 +116,11 @@ static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)

#define enqueue_pushable_task(rq, p) do { } while (0)
#define dequeue_pushable_task(rq, p) do { } while (0)
+#define inc_rt_migration(se, rq) do { } while (0)
+#define dec_rt_migration(se, rq) do { } while (0)

#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);
@@ -97,16 +144,6 @@ 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)

@@ -194,19 +231,6 @@ 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)

@@ -565,7 +589,7 @@ 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);

@@ -580,31 +604,29 @@ static inline int next_prio(struct rq *rq)
}
#endif

-static inline
-void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
+static void
+inc_rt_prio(struct rt_rq *rt_rq, int prio)
{
- int prio = rt_se_prio(rt_se);
-#ifdef CONFIG_SMP
- struct rq *rq = rq_of_rt_rq(rt_rq);
-#endif
+ int prev_prio = rt_rq->highest_prio.curr;

- 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)
+ rt_rq->highest_prio.curr = prio;
+
+#ifdef CONFIG_SMP
+ if (prio < prev_prio) {
+ struct rq *rq = rq_of_rt_rq(rt_rq);

/*
* 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
@@ -616,67 +638,86 @@ 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++;
-
- if (rt_rq->tg)
- start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
-#else
- start_rt_bandwidth(&def_rt_bandwidth);
+ rt_rq->highest_prio.next = next_prio(rq_of_rt_rq(rt_rq));
#endif
}

-static inline
-void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
+static void
+dec_rt_prio(struct rt_rq *rt_rq, int prio)
{
+ int prev_prio = rt_rq->highest_prio.curr;
+
#ifdef CONFIG_SMP
struct rq *rq = rq_of_rt_rq(rt_rq);
- int highest_prio = rt_rq->highest_prio.curr;
#endif

- 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
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 (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 != highest_prio)
+ if (rq->online && rt_rq->highest_prio.curr != prev_prio)
cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
+#endif
+
+}
+
+#else
+
+#define inc_rt_prio(rt_rq, prio) do { } while (0)
+#define dec_rt_prio(rt_rq, prio) do { } while (0)
+
+#endif /* CONFIG_SMP || 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);
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ if (rt_se_boosted(rt_se))
+ rt_rq->rt_nr_boosted++;
+
+ if (rt_rq->tg)
+ start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
+#else
+ start_rt_bandwidth(&def_rt_bandwidth);
+#endif
+}
+
+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);

- update_rt_migration(rq);
-#endif /* CONFIG_SMP */
#ifdef CONFIG_RT_GROUP_SCHED
if (rt_se_boosted(rt_se))
rt_rq->rt_nr_boosted--;
@@ -1451,7 +1492,7 @@ 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);

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