From: Steven Rostedt <rostedt@xxxxxxxxxxx>
Steve found these errors in the original patch
Signed-off-by: Gregory Haskins <ghaskins@xxxxxxxxxx>
---
kernel/sched.c | 15 ++++++++-
kernel/sched_rt.c | 90 +----------------------------------------------------
2 files changed, 15 insertions(+), 90 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 0dabf89..821f115 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1505,7 +1505,7 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
for_each_cpu_mask(cpu, *cpu_mask) {
struct rq *rq = &per_cpu(runqueues, cpu);
- if (cpu == smp_processor_id())
+ if (cpu == this_rq->cpu)
continue;
/* We look for lowest RT prio or non-rt CPU */
@@ -1533,7 +1533,8 @@ static struct rq *find_lock_lowest_rq(cpumask_t *cpu_mask,
* the mean time, task could have
* migrated already or had its affinity changed.
*/
- if (unlikely(task_rq(task) != this_rq ||
+ if (unlikely(task_running(this_rq, task) ||
+ task_rq(task) != this_rq ||
!cpu_isset(dst_cpu, task->cpus_allowed))) {
spin_unlock(&lowest_rq->lock);
lowest_rq = NULL;
@@ -2342,6 +2343,7 @@ static inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
spin_unlock(&rq->lock);
}
#endif
+
fire_sched_in_preempt_notifiers(current);
trace_stop_sched_switched(current);
/*
@@ -4064,6 +4066,15 @@ asmlinkage void __sched __schedule(void)
context_switch(rq, prev, next); /* unlocks the rq */
__preempt_enable_no_resched();
} else {
+#if defined(CONFIG_PREEMPT_RT) && defined(CONFIG_SMP)
+ /*
+ * If we hit the condition where we do not need to actually
+ * reschedule, we need to check if there are any tasks that
+ * should be pushed away
+ */
+ if (unlikely(rq->rt_nr_running > 1))
+ push_rt_tasks(rq);
+#endif
__preempt_enable_no_resched();
spin_unlock(&rq->lock);
trace_stop_sched_switched(next);
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 8d59e62..546526b 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -146,100 +146,14 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
p->se.exec_start = 0;
}
-/*
- * Load-balancing iterator. Note: while the runqueue stays locked
- * during the whole iteration, the current task might be
- * dequeued so the iterator has to be dequeue-safe. Here we
- * achieve that by always pre-iterating before returning
- * the current task:
- */
-static struct task_struct *load_balance_start_rt(void *arg)
-{
- struct rq *rq = arg;
- struct rt_prio_array *array = &rq->rt.active;
- struct list_head *head, *curr;
- struct task_struct *p;
- int idx;
-
- idx = sched_find_first_bit(array->bitmap);
- if (idx >= MAX_RT_PRIO)
- return NULL;
-
- head = array->queue + idx;
- curr = head->prev;
-
- p = list_entry(curr, struct task_struct, run_list);
-
- curr = curr->prev;
-
- rq->rt.rt_load_balance_idx = idx;
- rq->rt.rt_load_balance_head = head;
- rq->rt.rt_load_balance_curr = curr;
-
- return p;
-}
-
-static struct task_struct *load_balance_next_rt(void *arg)
-{
- struct rq *rq = arg;
- struct rt_prio_array *array = &rq->rt.active;
- struct list_head *head, *curr;
- struct task_struct *p;
- int idx;
-
- idx = rq->rt.rt_load_balance_idx;
- head = rq->rt.rt_load_balance_head;
- curr = rq->rt.rt_load_balance_curr;
-
- /*
- * If we arrived back to the head again then
- * iterate to the next queue (if any):
- */
- if (unlikely(head == curr)) {
- int next_idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
-
- if (next_idx >= MAX_RT_PRIO)
- return NULL;
-
- idx = next_idx;
- head = array->queue + idx;
- curr = head->prev;
-
- rq->rt.rt_load_balance_idx = idx;
- rq->rt.rt_load_balance_head = head;
- }
-
- p = list_entry(curr, struct task_struct, run_list);
-
- curr = curr->prev;
-
- rq->rt.rt_load_balance_curr = curr;
-
- return p;
-}
-
static unsigned long
load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_nr_move, unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
- int nr_moved;
- struct rq_iterator rt_rq_iterator;
- unsigned long load_moved;
-
- rt_rq_iterator.start = load_balance_start_rt;
- rt_rq_iterator.next = load_balance_next_rt;
- /* pass 'busiest' rq argument into
- * load_balance_[start|next]_rt iterators
- */
- rt_rq_iterator.arg = busiest;
-
- nr_moved = balance_tasks(this_rq, this_cpu, busiest, max_nr_move,
- max_load_move, sd, idle, all_pinned, &load_moved,
- this_best_prio, &rt_rq_iterator);
-
- return load_moved;
+ /* No passive migration for RT */
+ return 0;
}
static void task_tick_rt(struct rq *rq, struct task_struct *p)
-
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
