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sched/core: Provide a tsk_nr_cpus_allowed() helper
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tsk_nr_cpus_allowed() is an accessor for task->nr_cpus_allowed which allows
us to change the representation of ->nr_cpus_allowed if required.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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@KAGA-KOKO
KAGA-KOKO authored and Ingo Molnar committed May 12, 2016
1 parent ade42e0 commit 50605ff
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Showing 4 changed files with 32 additions and 27 deletions.
5 changes: 5 additions & 0 deletions include/linux/sched.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1930,6 +1930,11 @@ extern int arch_task_struct_size __read_mostly;
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)

static inline int tsk_nr_cpus_allowed(struct task_struct *p)
{
return p->nr_cpus_allowed;
}

#define TNF_MIGRATED 0x01
#define TNF_NO_GROUP 0x02
#define TNF_SHARED 0x04
Expand Down
2 changes: 1 addition & 1 deletion kernel/sched/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1585,7 +1585,7 @@ int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
{
lockdep_assert_held(&p->pi_lock);

if (p->nr_cpus_allowed > 1)
if (tsk_nr_cpus_allowed(p) > 1)
cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);
else
cpu = cpumask_any(tsk_cpus_allowed(p));
Expand Down
28 changes: 14 additions & 14 deletions kernel/sched/deadline.c
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Original file line number Diff line number Diff line change
Expand Up @@ -134,7 +134,7 @@ static void inc_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
{
struct task_struct *p = dl_task_of(dl_se);

if (p->nr_cpus_allowed > 1)
if (tsk_nr_cpus_allowed(p) > 1)
dl_rq->dl_nr_migratory++;

update_dl_migration(dl_rq);
Expand All @@ -144,7 +144,7 @@ static void dec_dl_migration(struct sched_dl_entity *dl_se, struct dl_rq *dl_rq)
{
struct task_struct *p = dl_task_of(dl_se);

if (p->nr_cpus_allowed > 1)
if (tsk_nr_cpus_allowed(p) > 1)
dl_rq->dl_nr_migratory--;

update_dl_migration(dl_rq);
Expand Down Expand Up @@ -966,7 +966,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)

enqueue_dl_entity(&p->dl, pi_se, flags);

if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
if (!task_current(rq, p) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_dl_task(rq, p);
}

Expand Down Expand Up @@ -1040,9 +1040,9 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
* try to make it stay here, it might be important.
*/
if (unlikely(dl_task(curr)) &&
(curr->nr_cpus_allowed < 2 ||
(tsk_nr_cpus_allowed(curr) < 2 ||
!dl_entity_preempt(&p->dl, &curr->dl)) &&
(p->nr_cpus_allowed > 1)) {
(tsk_nr_cpus_allowed(p) > 1)) {
int target = find_later_rq(p);

if (target != -1 &&
Expand All @@ -1063,15 +1063,15 @@ static void check_preempt_equal_dl(struct rq *rq, struct task_struct *p)
* Current can't be migrated, useless to reschedule,
* let's hope p can move out.
*/
if (rq->curr->nr_cpus_allowed == 1 ||
if (tsk_nr_cpus_allowed(rq->curr) == 1 ||
cpudl_find(&rq->rd->cpudl, rq->curr, NULL) == -1)
return;

/*
* p is migratable, so let's not schedule it and
* see if it is pushed or pulled somewhere else.
*/
if (p->nr_cpus_allowed != 1 &&
if (tsk_nr_cpus_allowed(p) != 1 &&
cpudl_find(&rq->rd->cpudl, p, NULL) != -1)
return;

Expand Down Expand Up @@ -1186,7 +1186,7 @@ static void put_prev_task_dl(struct rq *rq, struct task_struct *p)
{
update_curr_dl(rq);

if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1)
if (on_dl_rq(&p->dl) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_dl_task(rq, p);
}

Expand Down Expand Up @@ -1287,7 +1287,7 @@ static int find_later_rq(struct task_struct *task)
if (unlikely(!later_mask))
return -1;

if (task->nr_cpus_allowed == 1)
if (tsk_nr_cpus_allowed(task) == 1)
return -1;

/*
Expand Down Expand Up @@ -1433,7 +1433,7 @@ static struct task_struct *pick_next_pushable_dl_task(struct rq *rq)

BUG_ON(rq->cpu != task_cpu(p));
BUG_ON(task_current(rq, p));
BUG_ON(p->nr_cpus_allowed <= 1);
BUG_ON(tsk_nr_cpus_allowed(p) <= 1);

BUG_ON(!task_on_rq_queued(p));
BUG_ON(!dl_task(p));
Expand Down Expand Up @@ -1472,7 +1472,7 @@ static int push_dl_task(struct rq *rq)
*/
if (dl_task(rq->curr) &&
dl_time_before(next_task->dl.deadline, rq->curr->dl.deadline) &&
rq->curr->nr_cpus_allowed > 1) {
tsk_nr_cpus_allowed(rq->curr) > 1) {
resched_curr(rq);
return 0;
}
Expand Down Expand Up @@ -1619,9 +1619,9 @@ static void task_woken_dl(struct rq *rq, struct task_struct *p)
{
if (!task_running(rq, p) &&
!test_tsk_need_resched(rq->curr) &&
p->nr_cpus_allowed > 1 &&
tsk_nr_cpus_allowed(p) > 1 &&
dl_task(rq->curr) &&
(rq->curr->nr_cpus_allowed < 2 ||
(tsk_nr_cpus_allowed(rq->curr) < 2 ||
!dl_entity_preempt(&p->dl, &rq->curr->dl))) {
push_dl_tasks(rq);
}
Expand Down Expand Up @@ -1725,7 +1725,7 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)

if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)
if (tsk_nr_cpus_allowed(p) > 1 && rq->dl.overloaded)
queue_push_tasks(rq);
#else
if (dl_task(rq->curr))
Expand Down
24 changes: 12 additions & 12 deletions kernel/sched/rt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -334,7 +334,7 @@ static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
rt_rq = &rq_of_rt_rq(rt_rq)->rt;

rt_rq->rt_nr_total++;
if (p->nr_cpus_allowed > 1)
if (tsk_nr_cpus_allowed(p) > 1)
rt_rq->rt_nr_migratory++;

update_rt_migration(rt_rq);
Expand All @@ -351,7 +351,7 @@ static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
rt_rq = &rq_of_rt_rq(rt_rq)->rt;

rt_rq->rt_nr_total--;
if (p->nr_cpus_allowed > 1)
if (tsk_nr_cpus_allowed(p) > 1)
rt_rq->rt_nr_migratory--;

update_rt_migration(rt_rq);
Expand Down Expand Up @@ -1324,7 +1324,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)

enqueue_rt_entity(rt_se, flags);

if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
if (!task_current(rq, p) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_task(rq, p);
}

Expand Down Expand Up @@ -1413,7 +1413,7 @@ select_task_rq_rt(struct task_struct *p, int cpu, int sd_flag, int flags)
* will have to sort it out.
*/
if (curr && unlikely(rt_task(curr)) &&
(curr->nr_cpus_allowed < 2 ||
(tsk_nr_cpus_allowed(curr) < 2 ||
curr->prio <= p->prio)) {
int target = find_lowest_rq(p);

Expand All @@ -1437,15 +1437,15 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
* Current can't be migrated, useless to reschedule,
* let's hope p can move out.
*/
if (rq->curr->nr_cpus_allowed == 1 ||
if (tsk_nr_cpus_allowed(rq->curr) == 1 ||
!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
return;

/*
* p is migratable, so let's not schedule it and
* see if it is pushed or pulled somewhere else.
*/
if (p->nr_cpus_allowed != 1
if (tsk_nr_cpus_allowed(p) != 1
&& cpupri_find(&rq->rd->cpupri, p, NULL))
return;

Expand Down Expand Up @@ -1579,7 +1579,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
* The previous task needs to be made eligible for pushing
* if it is still active
*/
if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)
if (on_rt_rq(&p->rt) && tsk_nr_cpus_allowed(p) > 1)
enqueue_pushable_task(rq, p);
}

Expand Down Expand Up @@ -1629,7 +1629,7 @@ static int find_lowest_rq(struct task_struct *task)
if (unlikely(!lowest_mask))
return -1;

if (task->nr_cpus_allowed == 1)
if (tsk_nr_cpus_allowed(task) == 1)
return -1; /* No other targets possible */

if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
Expand Down Expand Up @@ -1762,7 +1762,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq)

BUG_ON(rq->cpu != task_cpu(p));
BUG_ON(task_current(rq, p));
BUG_ON(p->nr_cpus_allowed <= 1);
BUG_ON(tsk_nr_cpus_allowed(p) <= 1);

BUG_ON(!task_on_rq_queued(p));
BUG_ON(!rt_task(p));
Expand Down Expand Up @@ -2122,9 +2122,9 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
{
if (!task_running(rq, p) &&
!test_tsk_need_resched(rq->curr) &&
p->nr_cpus_allowed > 1 &&
tsk_nr_cpus_allowed(p) > 1 &&
(dl_task(rq->curr) || rt_task(rq->curr)) &&
(rq->curr->nr_cpus_allowed < 2 ||
(tsk_nr_cpus_allowed(rq->curr) < 2 ||
rq->curr->prio <= p->prio))
push_rt_tasks(rq);
}
Expand Down Expand Up @@ -2197,7 +2197,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
*/
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
if (tsk_nr_cpus_allowed(p) > 1 && rq->rt.overloaded)
queue_push_tasks(rq);
#else
if (p->prio < rq->curr->prio)
Expand Down

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