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authorPeter Williams <pwil3058@bigpond.net.au>2009-09-21 01:31:53 +0000
committerIngo Molnar <mingo@elte.hu>2009-09-21 09:53:55 +0200
commit0d721ceadbeaa24d7f9dd41b3e5e29912327a7e1 (patch)
tree54c0c8dc201122483bdd7e8975103b07f6afd34b
parentcb5fd13f1178dee4302646b2890d884c380160e1 (diff)
downloadlinux-0d721ceadbeaa24d7f9dd41b3e5e29912327a7e1.tar.bz2
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: Peter Williams <pwil3058@bigpond.net.au> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <06d1b89ee15a0eef82d7.1253496713@mudlark.pw.nest> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/sched.h2
-rw-r--r--kernel/sched.c17
-rw-r--r--kernel/sched_fair.c21
-rw-r--r--kernel/sched_idletask.c7
-rw-r--r--kernel/sched_rt.c13
5 files changed, 44 insertions, 16 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index cc37a3fa5065..239c8e0dba9f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -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
diff --git a/kernel/sched.c b/kernel/sched.c
index 1b900fb1c6e1..830967e18285 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -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;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 566e3bb78ed9..cd73738f0d5f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -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
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index a8b448af004b..b133a28fcde3 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -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,
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 13de7126a6ab..a4d790cddb19 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -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,
};