Commit 0d721cea authored by Peter Williams's avatar Peter Williams Committed by Ingo Molnar

sched: Simplify sys_sched_rr_get_interval() system call

By removing the need for it to know details of scheduling classes.

This allows PlugSched to define orthogonal scheduling classes.
Signed-off-by: default avatarPeter Williams <pwil3058@bigpond.net.au>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <06d1b89ee15a0eef82d7.1253496713@mudlark.pw.nest>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent cb5fd13f
......@@ -1075,6 +1075,8 @@ struct sched_class {
void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
int oldprio, int running);
unsigned int (*get_rr_interval) (struct task_struct *task);
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*moved_group) (struct task_struct *p);
#endif
......
......@@ -6819,23 +6819,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
if (retval)
goto out_unlock;
/*
* Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
* tasks that are on an otherwise idle runqueue:
*/
time_slice = 0;
if (p->policy == SCHED_RR) {
time_slice = DEF_TIMESLICE;
} else if (p->policy != SCHED_FIFO) {
struct sched_entity *se = &p->se;
unsigned long flags;
struct rq *rq;
time_slice = p->sched_class->get_rr_interval(p);
rq = task_rq_lock(p, &flags);
if (rq->cfs.load.weight)
time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
}
read_unlock(&tasklist_lock);
jiffies_to_timespec(time_slice, &t);
retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
......
......@@ -1938,6 +1938,25 @@ static void moved_group_fair(struct task_struct *p)
}
#endif
unsigned int get_rr_interval_fair(struct task_struct *task)
{
struct sched_entity *se = &task->se;
unsigned long flags;
struct rq *rq;
unsigned int rr_interval = 0;
/*
* Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
* idle runqueue:
*/
rq = task_rq_lock(task, &flags);
if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
return rr_interval;
}
/*
* All the scheduling class methods:
*/
......@@ -1966,6 +1985,8 @@ static const struct sched_class fair_sched_class = {
.prio_changed = prio_changed_fair,
.switched_to = switched_to_fair,
.get_rr_interval = get_rr_interval_fair,
#ifdef CONFIG_FAIR_GROUP_SCHED
.moved_group = moved_group_fair,
#endif
......
......@@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p,
check_preempt_curr(rq, p, 0);
}
unsigned int get_rr_interval_idle(struct task_struct *task)
{
return 0;
}
/*
* Simple, special scheduling class for the per-CPU idle tasks:
*/
......@@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = {
.set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
.get_rr_interval = get_rr_interval_idle,
.prio_changed = prio_changed_idle,
.switched_to = switched_to_idle,
......
......@@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq)
dequeue_pushable_task(rq, p);
}
unsigned int get_rr_interval_rt(struct task_struct *task)
{
/*
* Time slice is 0 for SCHED_FIFO tasks
*/
if (task->policy == SCHED_RR)
return DEF_TIMESLICE;
else
return 0;
}
static const struct sched_class rt_sched_class = {
.next = &fair_sched_class,
.enqueue_task = enqueue_task_rt,
......@@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = {
.set_curr_task = set_curr_task_rt,
.task_tick = task_tick_rt,
.get_rr_interval = get_rr_interval_rt,
.prio_changed = prio_changed_rt,
.switched_to = switched_to_rt,
};
......
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