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-rw-r--r--include/linux/sched.h7
-rw-r--r--kernel/sched.c99
-rw-r--r--kernel/sched_fair.c44
-rw-r--r--kernel/sched_idletask.c14
-rw-r--r--kernel/sched_rt.c28
5 files changed, 135 insertions, 57 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 52288a647692..639241f4f3d1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -829,11 +829,14 @@ struct sched_class {
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
- struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
+ struct rq *busiest, unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio);
+ int (*move_one_task) (struct rq *this_rq, int this_cpu,
+ struct rq *busiest, struct sched_domain *sd,
+ enum cpu_idle_type idle);
+
void (*set_curr_task) (struct rq *rq);
void (*task_tick) (struct rq *rq, struct task_struct *p);
void (*task_new) (struct rq *rq, struct task_struct *p);
diff --git a/kernel/sched.c b/kernel/sched.c
index cc9cd5b710a6..8607795fad69 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -838,11 +838,35 @@ struct rq_iterator {
struct task_struct *(*next)(void *);
};
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator);
+#ifdef CONFIG_SMP
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ unsigned long max_load_move, struct sched_domain *sd,
+ enum cpu_idle_type idle, int *all_pinned,
+ int *this_best_prio, struct rq_iterator *iterator);
+
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ struct rq_iterator *iterator);
+#else
+static inline unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ unsigned long max_load_move, struct sched_domain *sd,
+ enum cpu_idle_type idle, int *all_pinned,
+ int *this_best_prio, struct rq_iterator *iterator)
+{
+ return 0;
+}
+
+static inline int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ struct rq_iterator *iterator)
+{
+ return 0;
+}
+#endif
#include "sched_stats.h"
#include "sched_idletask.c"
@@ -2224,17 +2248,17 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
return 1;
}
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator)
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ unsigned long max_load_move, struct sched_domain *sd,
+ enum cpu_idle_type idle, int *all_pinned,
+ int *this_best_prio, struct rq_iterator *iterator)
{
int pulled = 0, pinned = 0, skip_for_load;
struct task_struct *p;
long rem_load_move = max_load_move;
- if (max_nr_move == 0 || max_load_move == 0)
+ if (max_load_move == 0)
goto out;
pinned = 1;
@@ -2267,7 +2291,7 @@ next:
* We only want to steal up to the prescribed number of tasks
* and the prescribed amount of weighted load.
*/
- if (pulled < max_nr_move && rem_load_move > 0) {
+ if (rem_load_move > 0) {
if (p->prio < *this_best_prio)
*this_best_prio = p->prio;
p = iterator->next(iterator->arg);
@@ -2275,7 +2299,7 @@ next:
}
out:
/*
- * Right now, this is the only place pull_task() is called,
+ * Right now, this is one of only two places pull_task() is called,
* so we can safely collect pull_task() stats here rather than
* inside pull_task().
*/
@@ -2283,8 +2307,8 @@ out:
if (all_pinned)
*all_pinned = pinned;
- *load_moved = max_load_move - rem_load_move;
- return pulled;
+
+ return max_load_move - rem_load_move;
}
/*
@@ -2306,7 +2330,7 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
do {
total_load_moved +=
class->load_balance(this_rq, this_cpu, busiest,
- ULONG_MAX, max_load_move - total_load_moved,
+ max_load_move - total_load_moved,
sd, idle, all_pinned, &this_best_prio);
class = class->next;
} while (class && max_load_move > total_load_moved);
@@ -2314,6 +2338,32 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
return total_load_moved > 0;
}
+static int
+iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ struct rq_iterator *iterator)
+{
+ struct task_struct *p = iterator->start(iterator->arg);
+ int pinned = 0;
+
+ while (p) {
+ if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
+ pull_task(busiest, p, this_rq, this_cpu);
+ /*
+ * Right now, this is only the second place pull_task()
+ * is called, so we can safely collect pull_task()
+ * stats here rather than inside pull_task().
+ */
+ schedstat_inc(sd, lb_gained[idle]);
+
+ return 1;
+ }
+ p = iterator->next(iterator->arg);
+ }
+
+ return 0;
+}
+
/*
* move_one_task tries to move exactly one task from busiest to this_rq, as
* part of active balancing operations within "domain".
@@ -2325,12 +2375,9 @@ static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
struct sched_domain *sd, enum cpu_idle_type idle)
{
const struct sched_class *class;
- int this_best_prio = MAX_PRIO;
for (class = sched_class_highest; class; class = class->next)
- if (class->load_balance(this_rq, this_cpu, busiest,
- 1, ULONG_MAX, sd, idle, NULL,
- &this_best_prio))
+ if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
return 1;
return 0;
@@ -3267,18 +3314,6 @@ static inline void idle_balance(int cpu, struct rq *rq)
{
}
-/* Avoid "used but not defined" warning on UP */
-static int balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, unsigned long *load_moved,
- int *this_best_prio, struct rq_iterator *iterator)
-{
- *load_moved = 0;
-
- return 0;
-}
-
#endif
DEFINE_PER_CPU(struct kernel_stat, kstat);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 166ed6db600b..a90d0457d603 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -936,12 +936,11 @@ static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
+ unsigned long max_load_move,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned, int *this_best_prio)
{
struct cfs_rq *busy_cfs_rq;
- unsigned long load_moved, total_nr_moved = 0, nr_moved;
long rem_load_move = max_load_move;
struct rq_iterator cfs_rq_iterator;
@@ -969,25 +968,47 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
#else
# define maxload rem_load_move
#endif
- /* pass busy_cfs_rq argument into
+ /*
+ * pass busy_cfs_rq argument into
* load_balance_[start|next]_fair iterators
*/
cfs_rq_iterator.arg = busy_cfs_rq;
- nr_moved = balance_tasks(this_rq, this_cpu, busiest,
- max_nr_move, maxload, sd, idle, all_pinned,
- &load_moved, this_best_prio, &cfs_rq_iterator);
-
- total_nr_moved += nr_moved;
- max_nr_move -= nr_moved;
- rem_load_move -= load_moved;
+ rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
+ maxload, sd, idle, all_pinned,
+ this_best_prio,
+ &cfs_rq_iterator);
- if (max_nr_move <= 0 || rem_load_move <= 0)
+ if (rem_load_move <= 0)
break;
}
return max_load_move - rem_load_move;
}
+static int
+move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle)
+{
+ struct cfs_rq *busy_cfs_rq;
+ struct rq_iterator cfs_rq_iterator;
+
+ cfs_rq_iterator.start = load_balance_start_fair;
+ cfs_rq_iterator.next = load_balance_next_fair;
+
+ for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
+ /*
+ * pass busy_cfs_rq argument into
+ * load_balance_[start|next]_fair iterators
+ */
+ cfs_rq_iterator.arg = busy_cfs_rq;
+ if (iter_move_one_task(this_rq, this_cpu, busiest, sd, idle,
+ &cfs_rq_iterator))
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* scheduler tick hitting a task of our scheduling class:
*/
@@ -1064,6 +1085,7 @@ static const struct sched_class fair_sched_class = {
.put_prev_task = put_prev_task_fair,
.load_balance = load_balance_fair,
+ .move_one_task = move_one_task_fair,
.set_curr_task = set_curr_task_fair,
.task_tick = task_tick_fair,
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 6e2ead41516e..586b06ca30aa 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -39,9 +39,16 @@ static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
static unsigned long
load_balance_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
+ unsigned long max_load_move,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ int *all_pinned, int *this_best_prio)
+{
+ return 0;
+}
+
+static int
+move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle)
{
return 0;
}
@@ -70,6 +77,7 @@ const struct sched_class idle_sched_class = {
.put_prev_task = put_prev_task_idle,
.load_balance = load_balance_idle,
+ .move_one_task = move_one_task_idle,
.set_curr_task = set_curr_task_idle,
.task_tick = task_tick_idle,
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index d0097a0634e5..e9395b7119e6 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -172,13 +172,11 @@ static struct task_struct *load_balance_next_rt(void *arg)
static unsigned long
load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_nr_move, unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
+ unsigned long max_load_move,
+ struct sched_domain *sd, enum cpu_idle_type idle,
+ int *all_pinned, int *this_best_prio)
{
- int nr_moved;
struct rq_iterator rt_rq_iterator;
- unsigned long load_moved;
rt_rq_iterator.start = load_balance_start_rt;
rt_rq_iterator.next = load_balance_next_rt;
@@ -187,11 +185,22 @@ load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
*/
rt_rq_iterator.arg = busiest;
- nr_moved = balance_tasks(this_rq, this_cpu, busiest, max_nr_move,
- max_load_move, sd, idle, all_pinned, &load_moved,
- this_best_prio, &rt_rq_iterator);
+ return balance_tasks(this_rq, this_cpu, busiest, max_load_move, sd,
+ idle, all_pinned, this_best_prio, &rt_rq_iterator);
+}
+
+static int
+move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
+ struct sched_domain *sd, enum cpu_idle_type idle)
+{
+ struct rq_iterator rt_rq_iterator;
+
+ rt_rq_iterator.start = load_balance_start_rt;
+ rt_rq_iterator.next = load_balance_next_rt;
+ rt_rq_iterator.arg = busiest;
- return load_moved;
+ return iter_move_one_task(this_rq, this_cpu, busiest, sd, idle,
+ &rt_rq_iterator);
}
static void task_tick_rt(struct rq *rq, struct task_struct *p)
@@ -237,6 +246,7 @@ const struct sched_class rt_sched_class = {
.put_prev_task = put_prev_task_rt,
.load_balance = load_balance_rt,
+ .move_one_task = move_one_task_rt,
.set_curr_task = set_curr_task_rt,
.task_tick = task_tick_rt,