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-rw-r--r--kernel/sched.c65
1 files changed, 47 insertions, 18 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 15db82116e19..ef748e691608 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2580,6 +2580,13 @@ out:
}
#ifdef CONFIG_SCHED_SMT
+static inline void wakeup_busy_runqueue(runqueue_t *rq)
+{
+ /* If an SMT runqueue is sleeping due to priority reasons wake it up */
+ if (rq->curr == rq->idle && rq->nr_running)
+ resched_task(rq->idle);
+}
+
static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq)
{
struct sched_domain *tmp, *sd = NULL;
@@ -2613,12 +2620,7 @@ static inline void wake_sleeping_dependent(int this_cpu, runqueue_t *this_rq)
for_each_cpu_mask(i, sibling_map) {
runqueue_t *smt_rq = cpu_rq(i);
- /*
- * If an SMT sibling task is sleeping due to priority
- * reasons wake it up now.
- */
- if (smt_rq->curr == smt_rq->idle && smt_rq->nr_running)
- resched_task(smt_rq->idle);
+ wakeup_busy_runqueue(smt_rq);
}
for_each_cpu_mask(i, sibling_map)
@@ -2672,6 +2674,10 @@ static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq)
runqueue_t *smt_rq = cpu_rq(i);
task_t *smt_curr = smt_rq->curr;
+ /* Kernel threads do not participate in dependent sleeping */
+ if (!p->mm || !smt_curr->mm || rt_task(p))
+ goto check_smt_task;
+
/*
* If a user task with lower static priority than the
* running task on the SMT sibling is trying to schedule,
@@ -2680,21 +2686,44 @@ static inline int dependent_sleeper(int this_cpu, runqueue_t *this_rq)
* task from using an unfair proportion of the
* physical cpu's resources. -ck
*/
- if (((smt_curr->time_slice * (100 - sd->per_cpu_gain) / 100) >
- task_timeslice(p) || rt_task(smt_curr)) &&
- p->mm && smt_curr->mm && !rt_task(p))
- ret = 1;
+ if (rt_task(smt_curr)) {
+ /*
+ * With real time tasks we run non-rt tasks only
+ * per_cpu_gain% of the time.
+ */
+ if ((jiffies % DEF_TIMESLICE) >
+ (sd->per_cpu_gain * DEF_TIMESLICE / 100))
+ ret = 1;
+ } else
+ if (((smt_curr->time_slice * (100 - sd->per_cpu_gain) /
+ 100) > task_timeslice(p)))
+ ret = 1;
+
+check_smt_task:
+ if ((!smt_curr->mm && smt_curr != smt_rq->idle) ||
+ rt_task(smt_curr))
+ continue;
+ if (!p->mm) {
+ wakeup_busy_runqueue(smt_rq);
+ continue;
+ }
/*
- * Reschedule a lower priority task on the SMT sibling,
- * or wake it up if it has been put to sleep for priority
- * reasons.
+ * Reschedule a lower priority task on the SMT sibling for
+ * it to be put to sleep, or wake it up if it has been put to
+ * sleep for priority reasons to see if it should run now.
*/
- if ((((p->time_slice * (100 - sd->per_cpu_gain) / 100) >
- task_timeslice(smt_curr) || rt_task(p)) &&
- smt_curr->mm && p->mm && !rt_task(smt_curr)) ||
- (smt_curr == smt_rq->idle && smt_rq->nr_running))
- resched_task(smt_curr);
+ if (rt_task(p)) {
+ if ((jiffies % DEF_TIMESLICE) >
+ (sd->per_cpu_gain * DEF_TIMESLICE / 100))
+ resched_task(smt_curr);
+ } else {
+ if ((p->time_slice * (100 - sd->per_cpu_gain) / 100) >
+ task_timeslice(smt_curr))
+ resched_task(smt_curr);
+ else
+ wakeup_busy_runqueue(smt_rq);
+ }
}
out_unlock:
for_each_cpu_mask(i, sibling_map)