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-rw-r--r--kernel/sched/deadline.c91
1 files changed, 53 insertions, 38 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 3958bc576d67..7f6de4316990 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -16,20 +16,6 @@
*/
#include "sched.h"
-static inline int dl_time_before(u64 a, u64 b)
-{
- return (s64)(a - b) < 0;
-}
-
-/*
- * Tells if entity @a should preempt entity @b.
- */
-static inline
-int dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
-{
- return dl_time_before(a->deadline, b->deadline);
-}
-
static inline struct task_struct *dl_task_of(struct sched_dl_entity *dl_se)
{
return container_of(dl_se, struct task_struct, dl);
@@ -242,7 +228,8 @@ static void check_preempt_curr_dl(struct rq *rq, struct task_struct *p,
* one, and to (try to!) reconcile itself with its own scheduling
* parameters.
*/
-static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
+static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
+ struct sched_dl_entity *pi_se)
{
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
@@ -254,8 +241,8 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
* future; in fact, we must consider execution overheads (time
* spent on hardirq context, etc.).
*/
- dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
- dl_se->runtime = dl_se->dl_runtime;
+ dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
+ dl_se->runtime = pi_se->dl_runtime;
dl_se->dl_new = 0;
}
@@ -277,11 +264,23 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
* could happen are, typically, a entity voluntarily trying to overcome its
* runtime, or it just underestimated it during sched_setscheduler_ex().
*/
-static void replenish_dl_entity(struct sched_dl_entity *dl_se)
+static void replenish_dl_entity(struct sched_dl_entity *dl_se,
+ struct sched_dl_entity *pi_se)
{
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
+ BUG_ON(pi_se->dl_runtime <= 0);
+
+ /*
+ * This could be the case for a !-dl task that is boosted.
+ * Just go with full inherited parameters.
+ */
+ if (dl_se->dl_deadline == 0) {
+ dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
+ dl_se->runtime = pi_se->dl_runtime;
+ }
+
/*
* We keep moving the deadline away until we get some
* available runtime for the entity. This ensures correct
@@ -289,8 +288,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
* arbitrary large.
*/
while (dl_se->runtime <= 0) {
- dl_se->deadline += dl_se->dl_period;
- dl_se->runtime += dl_se->dl_runtime;
+ dl_se->deadline += pi_se->dl_period;
+ dl_se->runtime += pi_se->dl_runtime;
}
/*
@@ -309,8 +308,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
lag_once = true;
printk_sched("sched: DL replenish lagged to much\n");
}
- dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
- dl_se->runtime = dl_se->dl_runtime;
+ dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
+ dl_se->runtime = pi_se->dl_runtime;
}
}
@@ -337,7 +336,8 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se)
* task with deadline equal to period this is the same of using
* dl_deadline instead of dl_period in the equation above.
*/
-static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t)
+static bool dl_entity_overflow(struct sched_dl_entity *dl_se,
+ struct sched_dl_entity *pi_se, u64 t)
{
u64 left, right;
@@ -359,8 +359,8 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t)
* of anything below microseconds resolution is actually fiction
* (but still we want to give the user that illusion >;).
*/
- left = (dl_se->dl_period >> 10) * (dl_se->runtime >> 10);
- right = ((dl_se->deadline - t) >> 10) * (dl_se->dl_runtime >> 10);
+ left = (pi_se->dl_period >> 10) * (dl_se->runtime >> 10);
+ right = ((dl_se->deadline - t) >> 10) * (pi_se->dl_runtime >> 10);
return dl_time_before(right, left);
}
@@ -374,7 +374,8 @@ static bool dl_entity_overflow(struct sched_dl_entity *dl_se, u64 t)
* - using the remaining runtime with the current deadline would make
* the entity exceed its bandwidth.
*/
-static void update_dl_entity(struct sched_dl_entity *dl_se)
+static void update_dl_entity(struct sched_dl_entity *dl_se,
+ struct sched_dl_entity *pi_se)
{
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
@@ -384,14 +385,14 @@ static void update_dl_entity(struct sched_dl_entity *dl_se)
* the actual scheduling parameters have to be "renewed".
*/
if (dl_se->dl_new) {
- setup_new_dl_entity(dl_se);
+ setup_new_dl_entity(dl_se, pi_se);
return;
}
if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
- dl_entity_overflow(dl_se, rq_clock(rq))) {
- dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
- dl_se->runtime = dl_se->dl_runtime;
+ dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
+ dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
+ dl_se->runtime = pi_se->dl_runtime;
}
}
@@ -405,7 +406,7 @@ static void update_dl_entity(struct sched_dl_entity *dl_se)
* actually started or not (i.e., the replenishment instant is in
* the future or in the past).
*/
-static int start_dl_timer(struct sched_dl_entity *dl_se)
+static int start_dl_timer(struct sched_dl_entity *dl_se, bool boosted)
{
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
@@ -414,6 +415,8 @@ static int start_dl_timer(struct sched_dl_entity *dl_se)
unsigned long range;
s64 delta;
+ if (boosted)
+ return 0;
/*
* We want the timer to fire at the deadline, but considering
* that it is actually coming from rq->clock and not from
@@ -573,7 +576,7 @@ static void update_curr_dl(struct rq *rq)
dl_se->runtime -= delta_exec;
if (dl_runtime_exceeded(rq, dl_se)) {
__dequeue_task_dl(rq, curr, 0);
- if (likely(start_dl_timer(dl_se)))
+ if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
dl_se->dl_throttled = 1;
else
enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
@@ -728,7 +731,8 @@ static void __dequeue_dl_entity(struct sched_dl_entity *dl_se)
}
static void
-enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags)
+enqueue_dl_entity(struct sched_dl_entity *dl_se,
+ struct sched_dl_entity *pi_se, int flags)
{
BUG_ON(on_dl_rq(dl_se));
@@ -738,9 +742,9 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags)
* we want a replenishment of its runtime.
*/
if (!dl_se->dl_new && flags & ENQUEUE_REPLENISH)
- replenish_dl_entity(dl_se);
+ replenish_dl_entity(dl_se, pi_se);
else
- update_dl_entity(dl_se);
+ update_dl_entity(dl_se, pi_se);
__enqueue_dl_entity(dl_se);
}
@@ -752,6 +756,18 @@ static void dequeue_dl_entity(struct sched_dl_entity *dl_se)
static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
{
+ struct task_struct *pi_task = rt_mutex_get_top_task(p);
+ struct sched_dl_entity *pi_se = &p->dl;
+
+ /*
+ * Use the scheduling parameters of the top pi-waiter
+ * task if we have one and its (relative) deadline is
+ * smaller than our one... OTW we keep our runtime and
+ * deadline.
+ */
+ if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio))
+ pi_se = &pi_task->dl;
+
/*
* If p is throttled, we do nothing. In fact, if it exhausted
* its budget it needs a replenishment and, since it now is on
@@ -761,7 +777,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
if (p->dl.dl_throttled)
return;
- enqueue_dl_entity(&p->dl, flags);
+ enqueue_dl_entity(&p->dl, pi_se, flags);
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
enqueue_pushable_dl_task(rq, p);
@@ -985,8 +1001,7 @@ static void task_dead_dl(struct task_struct *p)
{
struct hrtimer *timer = &p->dl.dl_timer;
- if (hrtimer_active(timer))
- hrtimer_try_to_cancel(timer);
+ hrtimer_cancel(timer);
}
static void set_curr_task_dl(struct rq *rq)