In order to evaluate the scheduler tick dependency without probing
context switches, we need to know how much SCHED_RR and SCHED_FIFO tasks
are enqueued as those policies don't have the same preemption
requirements.
To prepare for that, let's account SCHED_RR tasks, we'll be able to
deduce SCHED_FIFO tasks as well from it and the total RT tasks in the
runqueue.
Cc: Christoph Lameter <c...@linux.com>
Cc: Chris Metcalf <cmetc...@ezchip.com>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Luiz Capitulino <lcapitul...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Rik van Riel <r...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Viresh Kumar <viresh.ku...@linaro.org>
Signed-off-by: Frederic Weisbecker <fweis...@gmail.com>
---
kernel/sched/rt.c | 16 ++++++++++++++++
kernel/sched/sched.h | 1 +
2 files changed, 17 insertions(+)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index e3cc163..7e779a7 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1142,12 +1142,27 @@ unsigned int rt_se_nr_running(struct sched_rt_entity
*rt_se)
}
static inline
+unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
+{
+ struct rt_rq *group_rq = group_rt_rq(rt_se);
+ struct task_struct *tsk;
+
+ if (group_rq)
+ return group_rq->rr_nr_running;
+
+ tsk = rt_task_of(rt_se);
+
+ return (tsk->policy == SCHED_RR) ? 1 : 0;
+}
+
+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 += rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
inc_rt_prio(rt_rq, prio);
inc_rt_migration(rt_se, rt_rq);
@@ -1160,6 +1175,7 @@ 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 -= rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
dec_rt_prio(rt_rq, rt_se_prio(rt_se));
dec_rt_migration(rt_se, rt_rq);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index efd3bfc..6413238 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -437,6 +437,7 @@ static inline int rt_bandwidth_enabled(void)
struct rt_rq {
struct rt_prio_array active;
unsigned int rt_nr_running;
+ unsigned int rr_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
--
2.6.4
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