Doug / smarc-fsl-linux-kernel

1

/*

1

/*

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* Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR

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* Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR

3

* policies)

3

* policies)

4

*/

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*/

5

6

#include "sched.h"

6

#include "sched.h"

7

8

#include <linux/slab.h>

8

#include <linux/slab.h>

9

10

static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);

10

static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);

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12

struct rt_bandwidth def_rt_bandwidth;

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struct rt_bandwidth def_rt_bandwidth;

13

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static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)

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static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)

15

{

15

{

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struct rt_bandwidth *rt_b =

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struct rt_bandwidth *rt_b =

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container_of(timer, struct rt_bandwidth, rt_period_timer);

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container_of(timer, struct rt_bandwidth, rt_period_timer);

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ktime_t now;

18

ktime_t now;

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int overrun;

19

int overrun;

20

int idle = 0;

20

int idle = 0;

21

22

for (;;) {

22

for (;;) {

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now = hrtimer_cb_get_time(timer);

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now = hrtimer_cb_get_time(timer);

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overrun = hrtimer_forward(timer, now, rt_b->rt_period);

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overrun = hrtimer_forward(timer, now, rt_b->rt_period);

25

26

if (!overrun)

26

if (!overrun)

27

break;

27

break;

28

29

idle = do_sched_rt_period_timer(rt_b, overrun);

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idle = do_sched_rt_period_timer(rt_b, overrun);

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}

30

}

31

32

return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;

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return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;

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}

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}

34

35

void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)

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void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)

36

{

36

{

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rt_b->rt_period = ns_to_ktime(period);

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rt_b->rt_period = ns_to_ktime(period);

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rt_b->rt_runtime = runtime;

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rt_b->rt_runtime = runtime;

39

40

raw_spin_lock_init(&rt_b->rt_runtime_lock);

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raw_spin_lock_init(&rt_b->rt_runtime_lock);

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42

hrtimer_init(&rt_b->rt_period_timer,

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hrtimer_init(&rt_b->rt_period_timer,

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CLOCK_MONOTONIC, HRTIMER_MODE_REL);

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CLOCK_MONOTONIC, HRTIMER_MODE_REL);

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rt_b->rt_period_timer.function = sched_rt_period_timer;

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rt_b->rt_period_timer.function = sched_rt_period_timer;

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}

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}

46

47

static void start_rt_bandwidth(struct rt_bandwidth *rt_b)

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static void start_rt_bandwidth(struct rt_bandwidth *rt_b)

48

{

48

{

49

if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)

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if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)

50

return;

50

return;

51

52

if (hrtimer_active(&rt_b->rt_period_timer))

52

if (hrtimer_active(&rt_b->rt_period_timer))

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return;

53

return;

54

55

raw_spin_lock(&rt_b->rt_runtime_lock);

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raw_spin_lock(&rt_b->rt_runtime_lock);

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start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);

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start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);

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raw_spin_unlock(&rt_b->rt_runtime_lock);

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raw_spin_unlock(&rt_b->rt_runtime_lock);

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}

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}

59

60

void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)

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void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)

61

{

61

{

62

struct rt_prio_array *array;

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struct rt_prio_array *array;

63

int i;

63

int i;

64

65

array = &rt_rq->active;

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array = &rt_rq->active;

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for (i = 0; i < MAX_RT_PRIO; i++) {

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for (i = 0; i < MAX_RT_PRIO; i++) {

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INIT_LIST_HEAD(array->queue + i);

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INIT_LIST_HEAD(array->queue + i);

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__clear_bit(i, array->bitmap);

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__clear_bit(i, array->bitmap);

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}

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}

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/* delimiter for bitsearch: */

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/* delimiter for bitsearch: */

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__set_bit(MAX_RT_PRIO, array->bitmap);

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__set_bit(MAX_RT_PRIO, array->bitmap);

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#if defined CONFIG_SMP

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#if defined CONFIG_SMP

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rt_rq->highest_prio.curr = MAX_RT_PRIO;

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rt_rq->highest_prio.curr = MAX_RT_PRIO;

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rt_rq->highest_prio.next = MAX_RT_PRIO;

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rt_rq->highest_prio.next = MAX_RT_PRIO;

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rt_rq->rt_nr_migratory = 0;

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rt_rq->rt_nr_migratory = 0;

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rt_rq->overloaded = 0;

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rt_rq->overloaded = 0;

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plist_head_init(&rt_rq->pushable_tasks);

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plist_head_init(&rt_rq->pushable_tasks);

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#endif

79

#endif

80

81

rt_rq->rt_time = 0;

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rt_rq->rt_time = 0;

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rt_rq->rt_throttled = 0;

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rt_rq->rt_throttled = 0;

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rt_rq->rt_runtime = 0;

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rt_rq->rt_runtime = 0;

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raw_spin_lock_init(&rt_rq->rt_runtime_lock);

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raw_spin_lock_init(&rt_rq->rt_runtime_lock);

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}

85

}

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87

#ifdef CONFIG_RT_GROUP_SCHED

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#ifdef CONFIG_RT_GROUP_SCHED

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static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)

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static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)

89

{

89

{

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hrtimer_cancel(&rt_b->rt_period_timer);

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hrtimer_cancel(&rt_b->rt_period_timer);

91

}

91

}

92

93

#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)

93

#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)

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95

static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)

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static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)

96

{

96

{

97

#ifdef CONFIG_SCHED_DEBUG

97

#ifdef CONFIG_SCHED_DEBUG

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WARN_ON_ONCE(!rt_entity_is_task(rt_se));

98

WARN_ON_ONCE(!rt_entity_is_task(rt_se));

99

#endif

99

#endif

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return container_of(rt_se, struct task_struct, rt);

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return container_of(rt_se, struct task_struct, rt);

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}

101

}

102

103

static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)

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static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)

104

{

104

{

105

return rt_rq->rq;

105

return rt_rq->rq;

106

}

106

}

107

108

static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)

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static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)

109

{

109

{

110

return rt_se->rt_rq;

110

return rt_se->rt_rq;

111

}

111

}

112

113

void free_rt_sched_group(struct task_group *tg)

113

void free_rt_sched_group(struct task_group *tg)

114

{

114

{

115

int i;

115

int i;

116

117

if (tg->rt_se)

117

if (tg->rt_se)

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destroy_rt_bandwidth(&tg->rt_bandwidth);

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destroy_rt_bandwidth(&tg->rt_bandwidth);

119

120

for_each_possible_cpu(i) {

120

for_each_possible_cpu(i) {

121

if (tg->rt_rq)

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if (tg->rt_rq)

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kfree(tg->rt_rq[i]);

122

kfree(tg->rt_rq[i]);

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if (tg->rt_se)

123

if (tg->rt_se)

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kfree(tg->rt_se[i]);

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kfree(tg->rt_se[i]);

125

}

125

}

126

127

kfree(tg->rt_rq);

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kfree(tg->rt_rq);

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kfree(tg->rt_se);

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kfree(tg->rt_se);

129

}

129

}

130

131

void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,

131

void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,

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struct sched_rt_entity *rt_se, int cpu,

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struct sched_rt_entity *rt_se, int cpu,

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struct sched_rt_entity *parent)

133

struct sched_rt_entity *parent)

134

{

134

{

135

struct rq *rq = cpu_rq(cpu);

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struct rq *rq = cpu_rq(cpu);

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137

rt_rq->highest_prio.curr = MAX_RT_PRIO;

137

rt_rq->highest_prio.curr = MAX_RT_PRIO;

138

rt_rq->rt_nr_boosted = 0;

138

rt_rq->rt_nr_boosted = 0;

139

rt_rq->rq = rq;

139

rt_rq->rq = rq;

140

rt_rq->tg = tg;

140

rt_rq->tg = tg;

141

142

tg->rt_rq[cpu] = rt_rq;

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tg->rt_rq[cpu] = rt_rq;

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tg->rt_se[cpu] = rt_se;

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tg->rt_se[cpu] = rt_se;

144

145

if (!rt_se)

145

if (!rt_se)

146

return;

146

return;

147

148

if (!parent)

148

if (!parent)

149

rt_se->rt_rq = &rq->rt;

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rt_se->rt_rq = &rq->rt;

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else

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else

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rt_se->rt_rq = parent->my_q;

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rt_se->rt_rq = parent->my_q;

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153

rt_se->my_q = rt_rq;

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rt_se->my_q = rt_rq;

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rt_se->parent = parent;

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rt_se->parent = parent;

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INIT_LIST_HEAD(&rt_se->run_list);

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INIT_LIST_HEAD(&rt_se->run_list);

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}

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}

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158

int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)

158

int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)

159

{

159

{

160

struct rt_rq *rt_rq;

160

struct rt_rq *rt_rq;

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struct sched_rt_entity *rt_se;

161

struct sched_rt_entity *rt_se;

162

int i;

162

int i;

163

164

tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);

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tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);

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if (!tg->rt_rq)

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if (!tg->rt_rq)

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goto err;

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goto err;

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tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);

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tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);

168

if (!tg->rt_se)

168

if (!tg->rt_se)

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goto err;

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goto err;

170

171

init_rt_bandwidth(&tg->rt_bandwidth,

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init_rt_bandwidth(&tg->rt_bandwidth,

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ktime_to_ns(def_rt_bandwidth.rt_period), 0);

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ktime_to_ns(def_rt_bandwidth.rt_period), 0);

173

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for_each_possible_cpu(i) {

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for_each_possible_cpu(i) {

175

rt_rq = kzalloc_node(sizeof(struct rt_rq),

175

rt_rq = kzalloc_node(sizeof(struct rt_rq),

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GFP_KERNEL, cpu_to_node(i));

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GFP_KERNEL, cpu_to_node(i));

177

if (!rt_rq)

177

if (!rt_rq)

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goto err;

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goto err;

179

180

rt_se = kzalloc_node(sizeof(struct sched_rt_entity),

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rt_se = kzalloc_node(sizeof(struct sched_rt_entity),

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GFP_KERNEL, cpu_to_node(i));

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GFP_KERNEL, cpu_to_node(i));

182

if (!rt_se)

182

if (!rt_se)

183

goto err_free_rq;

183

goto err_free_rq;

184

185

init_rt_rq(rt_rq, cpu_rq(i));

185

init_rt_rq(rt_rq, cpu_rq(i));

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rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;

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rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;

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init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);

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init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);

188

}

188

}

189

190

return 1;

190

return 1;

191

192

err_free_rq:

192

err_free_rq:

193

kfree(rt_rq);

193

kfree(rt_rq);

194

err:

194

err:

195

return 0;

195

return 0;

196

}

196

}

197

198

#else /* CONFIG_RT_GROUP_SCHED */

198

#else /* CONFIG_RT_GROUP_SCHED */

199

200

#define rt_entity_is_task(rt_se) (1)

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#define rt_entity_is_task(rt_se) (1)

201

202

static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)

202

static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)

203

{

203

{

204

return container_of(rt_se, struct task_struct, rt);

204

return container_of(rt_se, struct task_struct, rt);

205

}

205

}

206

207

static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)

207

static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)

208

{

208

{

209

return container_of(rt_rq, struct rq, rt);

209

return container_of(rt_rq, struct rq, rt);

210

}

210

}

211

212

static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)

212

static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)

213

{

213

{

214

struct task_struct *p = rt_task_of(rt_se);

214

struct task_struct *p = rt_task_of(rt_se);

215

struct rq *rq = task_rq(p);

215

struct rq *rq = task_rq(p);

216

217

return &rq->rt;

217

return &rq->rt;

218

}

218

}

219

220

void free_rt_sched_group(struct task_group *tg) { }

220

void free_rt_sched_group(struct task_group *tg) { }

221

222

int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)

222

int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)

223

{

223

{

224

return 1;

224

return 1;

225

}

225

}

226

#endif /* CONFIG_RT_GROUP_SCHED */

226

#endif /* CONFIG_RT_GROUP_SCHED */

227

228

#ifdef CONFIG_SMP

228

#ifdef CONFIG_SMP

229

230

static inline int rt_overloaded(struct rq *rq)

230

static inline int rt_overloaded(struct rq *rq)

231

{

231

{

232

return atomic_read(&rq->rd->rto_count);

232

return atomic_read(&rq->rd->rto_count);

233

}

233

}

234

235

static inline void rt_set_overload(struct rq *rq)

235

static inline void rt_set_overload(struct rq *rq)

236

{

236

{

237

if (!rq->online)

237

if (!rq->online)

238

return;

238

return;

239

240

cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);

240

cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);

241

/*

241

/*

242

* Make sure the mask is visible before we set

242

* Make sure the mask is visible before we set

243

* the overload count. That is checked to determine

243

* the overload count. That is checked to determine

244

* if we should look at the mask. It would be a shame

244

* if we should look at the mask. It would be a shame

245

* if we looked at the mask, but the mask was not

245

* if we looked at the mask, but the mask was not

246

* updated yet.

246

* updated yet.

247

*/

247

*/

248

wmb();

248

wmb();

249

atomic_inc(&rq->rd->rto_count);

249

atomic_inc(&rq->rd->rto_count);

250

}

250

}

251

252

static inline void rt_clear_overload(struct rq *rq)

252

static inline void rt_clear_overload(struct rq *rq)

253

{

253

{

254

if (!rq->online)

254

if (!rq->online)

255

return;

255

return;

256

257

/* the order here really doesn't matter */

257

/* the order here really doesn't matter */

258

atomic_dec(&rq->rd->rto_count);

258

atomic_dec(&rq->rd->rto_count);

259

cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);

259

cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);

260

}

260

}

261

262

static void update_rt_migration(struct rt_rq *rt_rq)

262

static void update_rt_migration(struct rt_rq *rt_rq)

263

{

263

{

264

if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {

264

if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {

265

if (!rt_rq->overloaded) {

265

if (!rt_rq->overloaded) {

266

rt_set_overload(rq_of_rt_rq(rt_rq));

266

rt_set_overload(rq_of_rt_rq(rt_rq));

267

rt_rq->overloaded = 1;

267

rt_rq->overloaded = 1;

268

}

268

}

269

} else if (rt_rq->overloaded) {

269

} else if (rt_rq->overloaded) {

270

rt_clear_overload(rq_of_rt_rq(rt_rq));

270

rt_clear_overload(rq_of_rt_rq(rt_rq));

271

rt_rq->overloaded = 0;

271

rt_rq->overloaded = 0;

272

}

272

}

273

}

273

}

274

275

static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

275

static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

276

{

276

{

277

struct task_struct *p;

277

struct task_struct *p;

278

279

if (!rt_entity_is_task(rt_se))

279

if (!rt_entity_is_task(rt_se))

280

return;

280

return;

281

282

p = rt_task_of(rt_se);

282

p = rt_task_of(rt_se);

283

rt_rq = &rq_of_rt_rq(rt_rq)->rt;

283

rt_rq = &rq_of_rt_rq(rt_rq)->rt;

284

285

rt_rq->rt_nr_total++;

285

rt_rq->rt_nr_total++;

286

if (p->nr_cpus_allowed > 1)

286

if (p->nr_cpus_allowed > 1)

287

rt_rq->rt_nr_migratory++;

287

rt_rq->rt_nr_migratory++;

288

289

update_rt_migration(rt_rq);

289

update_rt_migration(rt_rq);

290

}

290

}

291

292

static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

292

static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

293

{

293

{

294

struct task_struct *p;

294

struct task_struct *p;

295

296

if (!rt_entity_is_task(rt_se))

296

if (!rt_entity_is_task(rt_se))

297

return;

297

return;

298

299

p = rt_task_of(rt_se);

299

p = rt_task_of(rt_se);

300

rt_rq = &rq_of_rt_rq(rt_rq)->rt;

300

rt_rq = &rq_of_rt_rq(rt_rq)->rt;

301

302

rt_rq->rt_nr_total--;

302

rt_rq->rt_nr_total--;

303

if (p->nr_cpus_allowed > 1)

303

if (p->nr_cpus_allowed > 1)

304

rt_rq->rt_nr_migratory--;

304

rt_rq->rt_nr_migratory--;

305

306

update_rt_migration(rt_rq);

306

update_rt_migration(rt_rq);

307

}

307

}

308

309

static inline int has_pushable_tasks(struct rq *rq)

309

static inline int has_pushable_tasks(struct rq *rq)

310

{

310

{

311

return !plist_head_empty(&rq->rt.pushable_tasks);

311

return !plist_head_empty(&rq->rt.pushable_tasks);

312

}

312

}

313

314

static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)

314

static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)

315

{

315

{

316

plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);

316

plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);

317

plist_node_init(&p->pushable_tasks, p->prio);

317

plist_node_init(&p->pushable_tasks, p->prio);

318

plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);

318

plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);

319

320

/* Update the highest prio pushable task */

320

/* Update the highest prio pushable task */

321

if (p->prio < rq->rt.highest_prio.next)

321

if (p->prio < rq->rt.highest_prio.next)

322

rq->rt.highest_prio.next = p->prio;

322

rq->rt.highest_prio.next = p->prio;

323

}

323

}

324

325

static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)

325

static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)

326

{

326

{

327

plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);

327

plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);

328

329

/* Update the new highest prio pushable task */

329

/* Update the new highest prio pushable task */

330

if (has_pushable_tasks(rq)) {

330

if (has_pushable_tasks(rq)) {

331

p = plist_first_entry(&rq->rt.pushable_tasks,

331

p = plist_first_entry(&rq->rt.pushable_tasks,

332

struct task_struct, pushable_tasks);

332

struct task_struct, pushable_tasks);

333

rq->rt.highest_prio.next = p->prio;

333

rq->rt.highest_prio.next = p->prio;

334

} else

334

} else

335

rq->rt.highest_prio.next = MAX_RT_PRIO;

335

rq->rt.highest_prio.next = MAX_RT_PRIO;

336

}

336

}

337

338

#else

338

#else

339

340

static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)

340

static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)

341

{

341

{

342

}

342

}

343

344

static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)

344

static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)

345

{

345

{

346

}

346

}

347

348

static inline

348

static inline

349

void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

349

void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

350

{

350

{

351

}

351

}

352

353

static inline

353

static inline

354

void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

354

void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

355

{

355

{

356

}

356

}

357

358

#endif /* CONFIG_SMP */

358

#endif /* CONFIG_SMP */

359

360

static inline int on_rt_rq(struct sched_rt_entity *rt_se)

360

static inline int on_rt_rq(struct sched_rt_entity *rt_se)

361

{

361

{

362

return !list_empty(&rt_se->run_list);

362

return !list_empty(&rt_se->run_list);

363

}

363

}

364

365

#ifdef CONFIG_RT_GROUP_SCHED

365

#ifdef CONFIG_RT_GROUP_SCHED

366

367

static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

367

static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

368

{

368

{

369

if (!rt_rq->tg)

369

if (!rt_rq->tg)

370

return RUNTIME_INF;

370

return RUNTIME_INF;

371

372

return rt_rq->rt_runtime;

372

return rt_rq->rt_runtime;

373

}

373

}

374

375

static inline u64 sched_rt_period(struct rt_rq *rt_rq)

375

static inline u64 sched_rt_period(struct rt_rq *rt_rq)

376

{

376

{

377

return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);

377

return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);

378

}

378

}

379

380

typedef struct task_group *rt_rq_iter_t;

380

typedef struct task_group *rt_rq_iter_t;

381

382

static inline struct task_group *next_task_group(struct task_group *tg)

382

static inline struct task_group *next_task_group(struct task_group *tg)

383

{

383

{

384

do {

384

do {

385

tg = list_entry_rcu(tg->list.next,

385

tg = list_entry_rcu(tg->list.next,

386

typeof(struct task_group), list);

386

typeof(struct task_group), list);

387

} while (&tg->list != &task_groups && task_group_is_autogroup(tg));

387

} while (&tg->list != &task_groups && task_group_is_autogroup(tg));

388

389

if (&tg->list == &task_groups)

389

if (&tg->list == &task_groups)

390

tg = NULL;

390

tg = NULL;

391

392

return tg;

392

return tg;

393

}

393

}

394

395

#define for_each_rt_rq(rt_rq, iter, rq) \

395

#define for_each_rt_rq(rt_rq, iter, rq) \

396

for (iter = container_of(&task_groups, typeof(*iter), list); \

396

for (iter = container_of(&task_groups, typeof(*iter), list); \

397

(iter = next_task_group(iter)) && \

397

(iter = next_task_group(iter)) && \

398

(rt_rq = iter->rt_rq[cpu_of(rq)]);)

398

(rt_rq = iter->rt_rq[cpu_of(rq)]);)

399

400

static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)

400

static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)

401

{

401

{

402

list_add_rcu(&rt_rq->leaf_rt_rq_list,

402

list_add_rcu(&rt_rq->leaf_rt_rq_list,

403

&rq_of_rt_rq(rt_rq)->leaf_rt_rq_list);

403

&rq_of_rt_rq(rt_rq)->leaf_rt_rq_list);

404

}

404

}

405

406

static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)

406

static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)

407

{

407

{

408

list_del_rcu(&rt_rq->leaf_rt_rq_list);

408

list_del_rcu(&rt_rq->leaf_rt_rq_list);

409

}

409

}

410

411

#define for_each_leaf_rt_rq(rt_rq, rq) \

411

#define for_each_leaf_rt_rq(rt_rq, rq) \

412

list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)

412

list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)

413

414

#define for_each_sched_rt_entity(rt_se) \

414

#define for_each_sched_rt_entity(rt_se) \

415

for (; rt_se; rt_se = rt_se->parent)

415

for (; rt_se; rt_se = rt_se->parent)

416

417

static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)

417

static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)

418

{

418

{

419

return rt_se->my_q;

419

return rt_se->my_q;

420

}

420

}

421

422

static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);

422

static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);

423

static void dequeue_rt_entity(struct sched_rt_entity *rt_se);

423

static void dequeue_rt_entity(struct sched_rt_entity *rt_se);

424

425

static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)

425

static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)

426

{

426

{

427

struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;

427

struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;

428

struct sched_rt_entity *rt_se;

428

struct sched_rt_entity *rt_se;

429

430

int cpu = cpu_of(rq_of_rt_rq(rt_rq));

430

int cpu = cpu_of(rq_of_rt_rq(rt_rq));

431

432

rt_se = rt_rq->tg->rt_se[cpu];

432

rt_se = rt_rq->tg->rt_se[cpu];

433

434

if (rt_rq->rt_nr_running) {

434

if (rt_rq->rt_nr_running) {

435

if (rt_se && !on_rt_rq(rt_se))

435

if (rt_se && !on_rt_rq(rt_se))

436

enqueue_rt_entity(rt_se, false);

436

enqueue_rt_entity(rt_se, false);

437

if (rt_rq->highest_prio.curr < curr->prio)

437

if (rt_rq->highest_prio.curr < curr->prio)

438

resched_task(curr);

438

resched_task(curr);

439

}

439

}

440

}

440

}

441

442

static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)

442

static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)

443

{

443

{

444

struct sched_rt_entity *rt_se;

444

struct sched_rt_entity *rt_se;

445

int cpu = cpu_of(rq_of_rt_rq(rt_rq));

445

int cpu = cpu_of(rq_of_rt_rq(rt_rq));

446

447

rt_se = rt_rq->tg->rt_se[cpu];

447

rt_se = rt_rq->tg->rt_se[cpu];

448

449

if (rt_se && on_rt_rq(rt_se))

449

if (rt_se && on_rt_rq(rt_se))

450

dequeue_rt_entity(rt_se);

450

dequeue_rt_entity(rt_se);

451

}

451

}

452

453

static inline int rt_rq_throttled(struct rt_rq *rt_rq)

453

static inline int rt_rq_throttled(struct rt_rq *rt_rq)

454

{

454

{

455

return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;

455

return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;

456

}

456

}

457

458

static int rt_se_boosted(struct sched_rt_entity *rt_se)

458

static int rt_se_boosted(struct sched_rt_entity *rt_se)

459

{

459

{

460

struct rt_rq *rt_rq = group_rt_rq(rt_se);

460

struct rt_rq *rt_rq = group_rt_rq(rt_se);

461

struct task_struct *p;

461

struct task_struct *p;

462

463

if (rt_rq)

463

if (rt_rq)

464

return !!rt_rq->rt_nr_boosted;

464

return !!rt_rq->rt_nr_boosted;

465

466

p = rt_task_of(rt_se);

466

p = rt_task_of(rt_se);

467

return p->prio != p->normal_prio;

467

return p->prio != p->normal_prio;

468

}

468

}

469

470

#ifdef CONFIG_SMP

470

#ifdef CONFIG_SMP

471

static inline const struct cpumask *sched_rt_period_mask(void)

471

static inline const struct cpumask *sched_rt_period_mask(void)

472

{

472

{

473

return cpu_rq(smp_processor_id())->rd->span;

473

return cpu_rq(smp_processor_id())->rd->span;

474

}

474

}

475

#else

475

#else

476

static inline const struct cpumask *sched_rt_period_mask(void)

476

static inline const struct cpumask *sched_rt_period_mask(void)

477

{

477

{

478

return cpu_online_mask;

478

return cpu_online_mask;

479

}

479

}

480

#endif

480

#endif

481

482

static inline

482

static inline

483

struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)

483

struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)

484

{

484

{

485

return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];

485

return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];

486

}

486

}

487

488

static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)

488

static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)

489

{

489

{

490

return &rt_rq->tg->rt_bandwidth;

490

return &rt_rq->tg->rt_bandwidth;

491

}

491

}

492

493

#else /* !CONFIG_RT_GROUP_SCHED */

493

#else /* !CONFIG_RT_GROUP_SCHED */

494

495

static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

495

static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)

496

{

496

{

497

return rt_rq->rt_runtime;

497

return rt_rq->rt_runtime;

498

}

498

}

499

500

static inline u64 sched_rt_period(struct rt_rq *rt_rq)

500

static inline u64 sched_rt_period(struct rt_rq *rt_rq)

501

{

501

{

502

return ktime_to_ns(def_rt_bandwidth.rt_period);

502

return ktime_to_ns(def_rt_bandwidth.rt_period);

503

}

503

}

504

505

typedef struct rt_rq *rt_rq_iter_t;

505

typedef struct rt_rq *rt_rq_iter_t;

506

507

#define for_each_rt_rq(rt_rq, iter, rq) \

507

#define for_each_rt_rq(rt_rq, iter, rq) \

508

for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

508

for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

509

510

static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)

510

static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)

511

{

511

{

512

}

512

}

513

514

static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)

514

static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)

515

{

515

{

516

}

516

}

517

518

#define for_each_leaf_rt_rq(rt_rq, rq) \

518

#define for_each_leaf_rt_rq(rt_rq, rq) \

519

for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

519

for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)

520

521

#define for_each_sched_rt_entity(rt_se) \

521

#define for_each_sched_rt_entity(rt_se) \

522

for (; rt_se; rt_se = NULL)

522

for (; rt_se; rt_se = NULL)

523

524

static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)

524

static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)

525

{

525

{

526

return NULL;

526

return NULL;

527

}

527

}

528

529

static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)

529

static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)

530

{

530

{

531

if (rt_rq->rt_nr_running)

531

if (rt_rq->rt_nr_running)

532

resched_task(rq_of_rt_rq(rt_rq)->curr);

532

resched_task(rq_of_rt_rq(rt_rq)->curr);

533

}

533

}

534

535

static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)

535

static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)

536

{

536

{

537

}

537

}

538

539

static inline int rt_rq_throttled(struct rt_rq *rt_rq)

539

static inline int rt_rq_throttled(struct rt_rq *rt_rq)

540

{

540

{

541

return rt_rq->rt_throttled;

541

return rt_rq->rt_throttled;

542

}

542

}

543

544

static inline const struct cpumask *sched_rt_period_mask(void)

544

static inline const struct cpumask *sched_rt_period_mask(void)

545

{

545

{

546

return cpu_online_mask;

546

return cpu_online_mask;

547

}

547

}

548

549

static inline

549

static inline

550

struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)

550

struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)

551

{

551

{

552

return &cpu_rq(cpu)->rt;

552

return &cpu_rq(cpu)->rt;

553

}

553

}

554

555

static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)

555

static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)

556

{

556

{

557

return &def_rt_bandwidth;

557

return &def_rt_bandwidth;

558

}

558

}

559

560

#endif /* CONFIG_RT_GROUP_SCHED */

560

#endif /* CONFIG_RT_GROUP_SCHED */

561

562

#ifdef CONFIG_SMP

562

#ifdef CONFIG_SMP

563

/*

563

/*

564

* We ran out of runtime, see if we can borrow some from our neighbours.

564

* We ran out of runtime, see if we can borrow some from our neighbours.

565

*/

565

*/

566

static int do_balance_runtime(struct rt_rq *rt_rq)

566

static int do_balance_runtime(struct rt_rq *rt_rq)

567

{

567

{

568

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

568

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

569

struct root_domain *rd = cpu_rq(smp_processor_id())->rd;

569

struct root_domain *rd = cpu_rq(smp_processor_id())->rd;

570

int i, weight, more = 0;

570

int i, weight, more = 0;

571

u64 rt_period;

571

u64 rt_period;

572

573

weight = cpumask_weight(rd->span);

573

weight = cpumask_weight(rd->span);

574

575

raw_spin_lock(&rt_b->rt_runtime_lock);

575

raw_spin_lock(&rt_b->rt_runtime_lock);

576

rt_period = ktime_to_ns(rt_b->rt_period);

576

rt_period = ktime_to_ns(rt_b->rt_period);

577

for_each_cpu(i, rd->span) {

577

for_each_cpu(i, rd->span) {

578

struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);

578

struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);

579

s64 diff;

579

s64 diff;

580

581

if (iter == rt_rq)

581

if (iter == rt_rq)

582

continue;

582

continue;

583

584

raw_spin_lock(&iter->rt_runtime_lock);

584

raw_spin_lock(&iter->rt_runtime_lock);

585

/*

585

/*

586

* Either all rqs have inf runtime and there's nothing to steal

586

* Either all rqs have inf runtime and there's nothing to steal

587

* or __disable_runtime() below sets a specific rq to inf to

587

* or __disable_runtime() below sets a specific rq to inf to

588

* indicate its been disabled and disalow stealing.

588

* indicate its been disabled and disalow stealing.

589

*/

589

*/

590

if (iter->rt_runtime == RUNTIME_INF)

590

if (iter->rt_runtime == RUNTIME_INF)

591

goto next;

591

goto next;

592

593

/*

593

/*

594

* From runqueues with spare time, take 1/n part of their

594

* From runqueues with spare time, take 1/n part of their

595

* spare time, but no more than our period.

595

* spare time, but no more than our period.

596

*/

596

*/

597

diff = iter->rt_runtime - iter->rt_time;

597

diff = iter->rt_runtime - iter->rt_time;

598

if (diff > 0) {

598

if (diff > 0) {

599

diff = div_u64((u64)diff, weight);

599

diff = div_u64((u64)diff, weight);

600

if (rt_rq->rt_runtime + diff > rt_period)

600

if (rt_rq->rt_runtime + diff > rt_period)

601

diff = rt_period - rt_rq->rt_runtime;

601

diff = rt_period - rt_rq->rt_runtime;

602

iter->rt_runtime -= diff;

602

iter->rt_runtime -= diff;

603

rt_rq->rt_runtime += diff;

603

rt_rq->rt_runtime += diff;

604

more = 1;

604

more = 1;

605

if (rt_rq->rt_runtime == rt_period) {

605

if (rt_rq->rt_runtime == rt_period) {

606

raw_spin_unlock(&iter->rt_runtime_lock);

606

raw_spin_unlock(&iter->rt_runtime_lock);

607

break;

607

break;

608

}

608

}

609

}

609

}

610

raw_spin_unlock(&iter->rt_runtime_lock);

611

raw_spin_unlock(&iter->rt_runtime_lock);

612

}

612

}

613

raw_spin_unlock(&rt_b->rt_runtime_lock);

613

raw_spin_unlock(&rt_b->rt_runtime_lock);

614

615

return more;

615

return more;

616

}

616

}

617

618

/*

618

/*

619

* Ensure this RQ takes back all the runtime it lend to its neighbours.

619

* Ensure this RQ takes back all the runtime it lend to its neighbours.

620

*/

620

*/

621

static void __disable_runtime(struct rq *rq)

621

static void __disable_runtime(struct rq *rq)

622

{

622

{

623

struct root_domain *rd = rq->rd;

623

struct root_domain *rd = rq->rd;

624

rt_rq_iter_t iter;

624

rt_rq_iter_t iter;

625

struct rt_rq *rt_rq;

625

struct rt_rq *rt_rq;

626

627

if (unlikely(!scheduler_running))

627

if (unlikely(!scheduler_running))

628

return;

628

return;

629

630

for_each_rt_rq(rt_rq, iter, rq) {

630

for_each_rt_rq(rt_rq, iter, rq) {

631

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

631

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

632

s64 want;

632

s64 want;

633

int i;

633

int i;

634

635

raw_spin_lock(&rt_b->rt_runtime_lock);

635

raw_spin_lock(&rt_b->rt_runtime_lock);

636

raw_spin_lock(&rt_rq->rt_runtime_lock);

636

raw_spin_lock(&rt_rq->rt_runtime_lock);

637

/*

637

/*

638

* Either we're all inf and nobody needs to borrow, or we're

638

* Either we're all inf and nobody needs to borrow, or we're

639

* already disabled and thus have nothing to do, or we have

639

* already disabled and thus have nothing to do, or we have

640

* exactly the right amount of runtime to take out.

640

* exactly the right amount of runtime to take out.

641

*/

641

*/

642

if (rt_rq->rt_runtime == RUNTIME_INF ||

642

if (rt_rq->rt_runtime == RUNTIME_INF ||

643

rt_rq->rt_runtime == rt_b->rt_runtime)

643

rt_rq->rt_runtime == rt_b->rt_runtime)

644

goto balanced;

644

goto balanced;

645

raw_spin_unlock(&rt_rq->rt_runtime_lock);

645

raw_spin_unlock(&rt_rq->rt_runtime_lock);

646

647

/*

647

/*

648

* Calculate the difference between what we started out with

648

* Calculate the difference between what we started out with

649

* and what we current have, that's the amount of runtime

649

* and what we current have, that's the amount of runtime

650

* we lend and now have to reclaim.

650

* we lend and now have to reclaim.

651

*/

651

*/

652

want = rt_b->rt_runtime - rt_rq->rt_runtime;

652

want = rt_b->rt_runtime - rt_rq->rt_runtime;

653

654

/*

654

/*

655

* Greedy reclaim, take back as much as we can.

655

* Greedy reclaim, take back as much as we can.

656

*/

656

*/

657

for_each_cpu(i, rd->span) {

657

for_each_cpu(i, rd->span) {

658

struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);

658

struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);

659

s64 diff;

659

s64 diff;

660

661

/*

661

/*

662

* Can't reclaim from ourselves or disabled runqueues.

662

* Can't reclaim from ourselves or disabled runqueues.

663

*/

663

*/

664

if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)

664

if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)

665

continue;

665

continue;

666

667

raw_spin_lock(&iter->rt_runtime_lock);

667

raw_spin_lock(&iter->rt_runtime_lock);

668

if (want > 0) {

668

if (want > 0) {

669

diff = min_t(s64, iter->rt_runtime, want);

669

diff = min_t(s64, iter->rt_runtime, want);

670

iter->rt_runtime -= diff;

670

iter->rt_runtime -= diff;

671

want -= diff;

671

want -= diff;

672

} else {

672

} else {

673

iter->rt_runtime -= want;

673

iter->rt_runtime -= want;

674

want -= want;

674

want -= want;

675

}

675

}

676

raw_spin_unlock(&iter->rt_runtime_lock);

676

raw_spin_unlock(&iter->rt_runtime_lock);

677

678

if (!want)

678

if (!want)

679

break;

679

break;

680

}

680

}

681

682

raw_spin_lock(&rt_rq->rt_runtime_lock);

682

raw_spin_lock(&rt_rq->rt_runtime_lock);

683

/*

683

/*

684

* We cannot be left wanting - that would mean some runtime

684

* We cannot be left wanting - that would mean some runtime

685

* leaked out of the system.

685

* leaked out of the system.

686

*/

686

*/

687

BUG_ON(want);

687

BUG_ON(want);

688

balanced:

688

balanced:

689

/*

689

/*

690

* Disable all the borrow logic by pretending we have inf

690

* Disable all the borrow logic by pretending we have inf

691

* runtime - in which case borrowing doesn't make sense.

691

* runtime - in which case borrowing doesn't make sense.

692

*/

692

*/

693

rt_rq->rt_runtime = RUNTIME_INF;

693

rt_rq->rt_runtime = RUNTIME_INF;

694

rt_rq->rt_throttled = 0;

694

rt_rq->rt_throttled = 0;

695

raw_spin_unlock(&rt_rq->rt_runtime_lock);

695

raw_spin_unlock(&rt_rq->rt_runtime_lock);

696

raw_spin_unlock(&rt_b->rt_runtime_lock);

696

raw_spin_unlock(&rt_b->rt_runtime_lock);

697

}

697

}

698

}

698

}

699

700

static void disable_runtime(struct rq *rq)

700

static void disable_runtime(struct rq *rq)

701

{

701

{

702

unsigned long flags;

702

unsigned long flags;

703

704

raw_spin_lock_irqsave(&rq->lock, flags);

704

raw_spin_lock_irqsave(&rq->lock, flags);

705

__disable_runtime(rq);

705

__disable_runtime(rq);

706

raw_spin_unlock_irqrestore(&rq->lock, flags);

706

raw_spin_unlock_irqrestore(&rq->lock, flags);

707

}

707

}

708

709

static void __enable_runtime(struct rq *rq)

709

static void __enable_runtime(struct rq *rq)

710

{

710

{

711

rt_rq_iter_t iter;

711

rt_rq_iter_t iter;

712

struct rt_rq *rt_rq;

712

struct rt_rq *rt_rq;

713

714

if (unlikely(!scheduler_running))

714

if (unlikely(!scheduler_running))

715

return;

715

return;

716

717

/*

717

/*

718

* Reset each runqueue's bandwidth settings

718

* Reset each runqueue's bandwidth settings

719

*/

719

*/

720

for_each_rt_rq(rt_rq, iter, rq) {

720

for_each_rt_rq(rt_rq, iter, rq) {

721

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

721

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

722

723

raw_spin_lock(&rt_b->rt_runtime_lock);

723

raw_spin_lock(&rt_b->rt_runtime_lock);

724

raw_spin_lock(&rt_rq->rt_runtime_lock);

724

raw_spin_lock(&rt_rq->rt_runtime_lock);

725

rt_rq->rt_runtime = rt_b->rt_runtime;

725

rt_rq->rt_runtime = rt_b->rt_runtime;

726

rt_rq->rt_time = 0;

726

rt_rq->rt_time = 0;

727

rt_rq->rt_throttled = 0;

727

rt_rq->rt_throttled = 0;

728

raw_spin_unlock(&rt_rq->rt_runtime_lock);

728

raw_spin_unlock(&rt_rq->rt_runtime_lock);

729

raw_spin_unlock(&rt_b->rt_runtime_lock);

729

raw_spin_unlock(&rt_b->rt_runtime_lock);

730

}

730

}

731

}

731

}

732

733

static void enable_runtime(struct rq *rq)

733

static void enable_runtime(struct rq *rq)

734

{

734

{

735

unsigned long flags;

735

unsigned long flags;

736

737

raw_spin_lock_irqsave(&rq->lock, flags);

737

raw_spin_lock_irqsave(&rq->lock, flags);

738

__enable_runtime(rq);

738

__enable_runtime(rq);

739

raw_spin_unlock_irqrestore(&rq->lock, flags);

739

raw_spin_unlock_irqrestore(&rq->lock, flags);

740

}

740

}

741

742

int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu)

742

int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu)

743

{

743

{

744

int cpu = (int)(long)hcpu;

744

int cpu = (int)(long)hcpu;

745

746

switch (action) {

746

switch (action) {

747

case CPU_DOWN_PREPARE:

747

case CPU_DOWN_PREPARE:

748

case CPU_DOWN_PREPARE_FROZEN:

748

case CPU_DOWN_PREPARE_FROZEN:

749

disable_runtime(cpu_rq(cpu));

749

disable_runtime(cpu_rq(cpu));

750

return NOTIFY_OK;

750

return NOTIFY_OK;

751

752

case CPU_DOWN_FAILED:

752

case CPU_DOWN_FAILED:

753

case CPU_DOWN_FAILED_FROZEN:

753

case CPU_DOWN_FAILED_FROZEN:

754

case CPU_ONLINE:

754

case CPU_ONLINE:

755

case CPU_ONLINE_FROZEN:

755

case CPU_ONLINE_FROZEN:

756

enable_runtime(cpu_rq(cpu));

756

enable_runtime(cpu_rq(cpu));

757

return NOTIFY_OK;

757

return NOTIFY_OK;

758

759

default:

759

default:

760

return NOTIFY_DONE;

760

return NOTIFY_DONE;

761

}

761

}

762

}

762

}

763

764

static int balance_runtime(struct rt_rq *rt_rq)

764

static int balance_runtime(struct rt_rq *rt_rq)

765

{

765

{

766

int more = 0;

766

int more = 0;

767

768

if (!sched_feat(RT_RUNTIME_SHARE))

768

if (!sched_feat(RT_RUNTIME_SHARE))

769

return more;

769

return more;

770

771

if (rt_rq->rt_time > rt_rq->rt_runtime) {

771

if (rt_rq->rt_time > rt_rq->rt_runtime) {

772

raw_spin_unlock(&rt_rq->rt_runtime_lock);

772

raw_spin_unlock(&rt_rq->rt_runtime_lock);

773

more = do_balance_runtime(rt_rq);

773

more = do_balance_runtime(rt_rq);

774

raw_spin_lock(&rt_rq->rt_runtime_lock);

774

raw_spin_lock(&rt_rq->rt_runtime_lock);

775

}

775

}

776

777

return more;

777

return more;

778

}

778

}

779

#else /* !CONFIG_SMP */

779

#else /* !CONFIG_SMP */

780

static inline int balance_runtime(struct rt_rq *rt_rq)

780

static inline int balance_runtime(struct rt_rq *rt_rq)

781

{

781

{

782

return 0;

782

return 0;

783

}

783

}

784

#endif /* CONFIG_SMP */

784

#endif /* CONFIG_SMP */

785

786

static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)

786

static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)

787

{

787

{

788

int i, idle = 1, throttled = 0;

788

int i, idle = 1, throttled = 0;

789

const struct cpumask *span;

789

const struct cpumask *span;

790

791

span = sched_rt_period_mask();

791

span = sched_rt_period_mask();

792

#ifdef CONFIG_RT_GROUP_SCHED

792

#ifdef CONFIG_RT_GROUP_SCHED

793

/*

793

/*

794

* FIXME: isolated CPUs should really leave the root task group,

794

* FIXME: isolated CPUs should really leave the root task group,

795

* whether they are isolcpus or were isolated via cpusets, lest

795

* whether they are isolcpus or were isolated via cpusets, lest

796

* the timer run on a CPU which does not service all runqueues,

796

* the timer run on a CPU which does not service all runqueues,

797

* potentially leaving other CPUs indefinitely throttled. If

797

* potentially leaving other CPUs indefinitely throttled. If

798

* isolation is really required, the user will turn the throttle

798

* isolation is really required, the user will turn the throttle

799

* off to kill the perturbations it causes anyway. Meanwhile,

799

* off to kill the perturbations it causes anyway. Meanwhile,

800

* this maintains functionality for boot and/or troubleshooting.

800

* this maintains functionality for boot and/or troubleshooting.

801

*/

801

*/

802

if (rt_b == &root_task_group.rt_bandwidth)

802

if (rt_b == &root_task_group.rt_bandwidth)

803

span = cpu_online_mask;

803

span = cpu_online_mask;

804

#endif

804

#endif

805

for_each_cpu(i, span) {

805

for_each_cpu(i, span) {

806

int enqueue = 0;

806

int enqueue = 0;

807

struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);

807

struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);

808

struct rq *rq = rq_of_rt_rq(rt_rq);

808

struct rq *rq = rq_of_rt_rq(rt_rq);

809

810

raw_spin_lock(&rq->lock);

810

raw_spin_lock(&rq->lock);

811

if (rt_rq->rt_time) {

811

if (rt_rq->rt_time) {

812

u64 runtime;

812

u64 runtime;

813

814

raw_spin_lock(&rt_rq->rt_runtime_lock);

814

raw_spin_lock(&rt_rq->rt_runtime_lock);

815

if (rt_rq->rt_throttled)

815

if (rt_rq->rt_throttled)

816

balance_runtime(rt_rq);

816

balance_runtime(rt_rq);

817

runtime = rt_rq->rt_runtime;

817

runtime = rt_rq->rt_runtime;

818

rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);

818

rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);

819

if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {

819

if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {

820

rt_rq->rt_throttled = 0;

820

rt_rq->rt_throttled = 0;

821

enqueue = 1;

821

enqueue = 1;

822

823

/*

823

/*

824

* Force a clock update if the CPU was idle,

824

* Force a clock update if the CPU was idle,

825

* lest wakeup -> unthrottle time accumulate.

825

* lest wakeup -> unthrottle time accumulate.

826

*/

826

*/

827

if (rt_rq->rt_nr_running && rq->curr == rq->idle)

827

if (rt_rq->rt_nr_running && rq->curr == rq->idle)

828

rq->skip_clock_update = -1;

828

rq->skip_clock_update = -1;

829

}

829

}

830

if (rt_rq->rt_time || rt_rq->rt_nr_running)

830

if (rt_rq->rt_time || rt_rq->rt_nr_running)

831

idle = 0;

831

idle = 0;

832

raw_spin_unlock(&rt_rq->rt_runtime_lock);

832

raw_spin_unlock(&rt_rq->rt_runtime_lock);

833

} else if (rt_rq->rt_nr_running) {

833

} else if (rt_rq->rt_nr_running) {

834

idle = 0;

834

idle = 0;

835

if (!rt_rq_throttled(rt_rq))

835

if (!rt_rq_throttled(rt_rq))

836

enqueue = 1;

836

enqueue = 1;

837

}

837

}

838

if (rt_rq->rt_throttled)

838

if (rt_rq->rt_throttled)

839

throttled = 1;

839

throttled = 1;

840

841

if (enqueue)

841

if (enqueue)

842

sched_rt_rq_enqueue(rt_rq);

842

sched_rt_rq_enqueue(rt_rq);

843

raw_spin_unlock(&rq->lock);

843

raw_spin_unlock(&rq->lock);

844

}

844

}

845

846

if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))

846

if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))

847

return 1;

847

return 1;

848

849

return idle;

849

return idle;

850

}

850

}

851

852

static inline int rt_se_prio(struct sched_rt_entity *rt_se)

852

static inline int rt_se_prio(struct sched_rt_entity *rt_se)

853

{

853

{

854

#ifdef CONFIG_RT_GROUP_SCHED

854

#ifdef CONFIG_RT_GROUP_SCHED

855

struct rt_rq *rt_rq = group_rt_rq(rt_se);

855

struct rt_rq *rt_rq = group_rt_rq(rt_se);

856

857

if (rt_rq)

857

if (rt_rq)

858

return rt_rq->highest_prio.curr;

858

return rt_rq->highest_prio.curr;

859

#endif

859

#endif

860

861

return rt_task_of(rt_se)->prio;

861

return rt_task_of(rt_se)->prio;

862

}

862

}

863

864

static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)

864

static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)

865

{

865

{

866

u64 runtime = sched_rt_runtime(rt_rq);

866

u64 runtime = sched_rt_runtime(rt_rq);

867

868

if (rt_rq->rt_throttled)

868

if (rt_rq->rt_throttled)

869

return rt_rq_throttled(rt_rq);

869

return rt_rq_throttled(rt_rq);

870

871

if (runtime >= sched_rt_period(rt_rq))

871

if (runtime >= sched_rt_period(rt_rq))

872

return 0;

872

return 0;

873

874

balance_runtime(rt_rq);

874

balance_runtime(rt_rq);

875

runtime = sched_rt_runtime(rt_rq);

875

runtime = sched_rt_runtime(rt_rq);

876

if (runtime == RUNTIME_INF)

876

if (runtime == RUNTIME_INF)

877

return 0;

877

return 0;

878

879

if (rt_rq->rt_time > runtime) {

879

if (rt_rq->rt_time > runtime) {

880

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

880

struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);

881

882

/*

882

/*

883

* Don't actually throttle groups that have no runtime assigned

883

* Don't actually throttle groups that have no runtime assigned

884

* but accrue some time due to boosting.

884

* but accrue some time due to boosting.

885

*/

885

*/

886

if (likely(rt_b->rt_runtime)) {

886

if (likely(rt_b->rt_runtime)) {

887

static bool once = false;

887

static bool once = false;

888

889

rt_rq->rt_throttled = 1;

889

rt_rq->rt_throttled = 1;

890

891

if (!once) {

891

if (!once) {

892

once = true;

892

once = true;

893

printk_sched("sched: RT throttling activated\n");

893

printk_sched("sched: RT throttling activated\n");

894

}

894

}

895

} else {

895

} else {

896

/*

896

/*

897

* In case we did anyway, make it go away,

897

* In case we did anyway, make it go away,

898

* replenishment is a joke, since it will replenish us

898

* replenishment is a joke, since it will replenish us

899

* with exactly 0 ns.

899

* with exactly 0 ns.

900

*/

900

*/

901

rt_rq->rt_time = 0;

901

rt_rq->rt_time = 0;

902

}

902

}

903

904

if (rt_rq_throttled(rt_rq)) {

904

if (rt_rq_throttled(rt_rq)) {

905

sched_rt_rq_dequeue(rt_rq);

905

sched_rt_rq_dequeue(rt_rq);

906

return 1;

906

return 1;

907

}

907

}

908

}

908

}

909

910

return 0;

910

return 0;

911

}

911

}

912

913

/*

913

/*

914

* Update the current task's runtime statistics. Skip current tasks that

914

* Update the current task's runtime statistics. Skip current tasks that

915

* are not in our scheduling class.

915

* are not in our scheduling class.

916

*/

916

*/

917

static void update_curr_rt(struct rq *rq)

917

static void update_curr_rt(struct rq *rq)

918

{

918

{

919

struct task_struct *curr = rq->curr;

919

struct task_struct *curr = rq->curr;

920

struct sched_rt_entity *rt_se = &curr->rt;

920

struct sched_rt_entity *rt_se = &curr->rt;

921

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

921

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

922

u64 delta_exec;

922

u64 delta_exec;

923

924

if (curr->sched_class != &rt_sched_class)

924

if (curr->sched_class != &rt_sched_class)

925

return;

925

return;

926

927

delta_exec = rq->clock_task - curr->se.exec_start;

927

delta_exec = rq->clock_task - curr->se.exec_start;

928

if (unlikely((s64)delta_exec < 0))

928

if (unlikely((s64)delta_exec < 0))

929

delta_exec = 0;

929

delta_exec = 0;

930

931

schedstat_set(curr->se.statistics.exec_max,

931

schedstat_set(curr->se.statistics.exec_max,

932

max(curr->se.statistics.exec_max, delta_exec));

932

max(curr->se.statistics.exec_max, delta_exec));

933

934

curr->se.sum_exec_runtime += delta_exec;

934

curr->se.sum_exec_runtime += delta_exec;

935

account_group_exec_runtime(curr, delta_exec);

935

account_group_exec_runtime(curr, delta_exec);

936

937

curr->se.exec_start = rq->clock_task;

937

curr->se.exec_start = rq->clock_task;

938

cpuacct_charge(curr, delta_exec);

938

cpuacct_charge(curr, delta_exec);

939

940

sched_rt_avg_update(rq, delta_exec);

940

sched_rt_avg_update(rq, delta_exec);

941

942

if (!rt_bandwidth_enabled())

942

if (!rt_bandwidth_enabled())

943

return;

943

return;

944

945

for_each_sched_rt_entity(rt_se) {

945

for_each_sched_rt_entity(rt_se) {

946

rt_rq = rt_rq_of_se(rt_se);

946

rt_rq = rt_rq_of_se(rt_se);

947

948

if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {

948

if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {

949

raw_spin_lock(&rt_rq->rt_runtime_lock);

949

raw_spin_lock(&rt_rq->rt_runtime_lock);

950

rt_rq->rt_time += delta_exec;

950

rt_rq->rt_time += delta_exec;

951

if (sched_rt_runtime_exceeded(rt_rq))

951

if (sched_rt_runtime_exceeded(rt_rq))

952

resched_task(curr);

952

resched_task(curr);

953

raw_spin_unlock(&rt_rq->rt_runtime_lock);

953

raw_spin_unlock(&rt_rq->rt_runtime_lock);

954

}

954

}

955

}

955

}

956

}

956

}

957

958

#if defined CONFIG_SMP

958

#if defined CONFIG_SMP

959

960

static void

960

static void

961

inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)

961

inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)

962

{

962

{

963

struct rq *rq = rq_of_rt_rq(rt_rq);

963

struct rq *rq = rq_of_rt_rq(rt_rq);

964

965

if (rq->online && prio < prev_prio)

965

if (rq->online && prio < prev_prio)

966

cpupri_set(&rq->rd->cpupri, rq->cpu, prio);

966

cpupri_set(&rq->rd->cpupri, rq->cpu, prio);

967

}

967

}

968

969

static void

969

static void

970

dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)

970

dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)

971

{

971

{

972

struct rq *rq = rq_of_rt_rq(rt_rq);

972

struct rq *rq = rq_of_rt_rq(rt_rq);

973

974

if (rq->online && rt_rq->highest_prio.curr != prev_prio)

974

if (rq->online && rt_rq->highest_prio.curr != prev_prio)

975

cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);

975

cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);

976

}

976

}

977

978

#else /* CONFIG_SMP */

978

#else /* CONFIG_SMP */

979

980

static inline

980

static inline

981

void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}

981

void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}

982

static inline

982

static inline

983

void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}

983

void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}

984

985

#endif /* CONFIG_SMP */

985

#endif /* CONFIG_SMP */

986

987

#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED

987

#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED

988

static void

988

static void

989

inc_rt_prio(struct rt_rq *rt_rq, int prio)

989

inc_rt_prio(struct rt_rq *rt_rq, int prio)

990

{

990

{

991

int prev_prio = rt_rq->highest_prio.curr;

991

int prev_prio = rt_rq->highest_prio.curr;

992

993

if (prio < prev_prio)

993

if (prio < prev_prio)

994

rt_rq->highest_prio.curr = prio;

994

rt_rq->highest_prio.curr = prio;

995

996

inc_rt_prio_smp(rt_rq, prio, prev_prio);

996

inc_rt_prio_smp(rt_rq, prio, prev_prio);

997

}

997

}

998

999

static void

999

static void

1000

dec_rt_prio(struct rt_rq *rt_rq, int prio)

1000

dec_rt_prio(struct rt_rq *rt_rq, int prio)

1001

{

1001

{

1002

int prev_prio = rt_rq->highest_prio.curr;

1002

int prev_prio = rt_rq->highest_prio.curr;

1003

1004

if (rt_rq->rt_nr_running) {

1004

if (rt_rq->rt_nr_running) {

1005

1006

WARN_ON(prio < prev_prio);

1006

WARN_ON(prio < prev_prio);

1007

1008

/*

1008

/*

1009

* This may have been our highest task, and therefore

1009

* This may have been our highest task, and therefore

1010

* we may have some recomputation to do

1010

* we may have some recomputation to do

1011

*/

1011

*/

1012

if (prio == prev_prio) {

1012

if (prio == prev_prio) {

1013

struct rt_prio_array *array = &rt_rq->active;

1013

struct rt_prio_array *array = &rt_rq->active;

1014

1015

rt_rq->highest_prio.curr =

1015

rt_rq->highest_prio.curr =

1016

sched_find_first_bit(array->bitmap);

1016

sched_find_first_bit(array->bitmap);

1017

}

1017

}

1018

1019

} else

1019

} else

1020

rt_rq->highest_prio.curr = MAX_RT_PRIO;

1020

rt_rq->highest_prio.curr = MAX_RT_PRIO;

1021

1022

dec_rt_prio_smp(rt_rq, prio, prev_prio);

1022

dec_rt_prio_smp(rt_rq, prio, prev_prio);

1023

}

1023

}

1024

1025

#else

1025

#else

1026

1027

static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}

1027

static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}

1028

static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}

1028

static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}

1029

1030

#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */

1030

#endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */

1031

1032

#ifdef CONFIG_RT_GROUP_SCHED

1032

#ifdef CONFIG_RT_GROUP_SCHED

1033

1034

static void

1034

static void

1035

inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1035

inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1036

{

1036

{

1037

if (rt_se_boosted(rt_se))

1037

if (rt_se_boosted(rt_se))

1038

rt_rq->rt_nr_boosted++;

1038

rt_rq->rt_nr_boosted++;

1039

1040

if (rt_rq->tg)

1040

if (rt_rq->tg)

1041

start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);

1041

start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);

1042

}

1042

}

1043

1044

static void

1044

static void

1045

dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1045

dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1046

{

1046

{

1047

if (rt_se_boosted(rt_se))

1047

if (rt_se_boosted(rt_se))

1048

rt_rq->rt_nr_boosted--;

1048

rt_rq->rt_nr_boosted--;

1049

1050

WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);

1050

WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);

1051

}

1051

}

1052

1053

#else /* CONFIG_RT_GROUP_SCHED */

1053

#else /* CONFIG_RT_GROUP_SCHED */

1054

1055

static void

1055

static void

1056

inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1056

inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1057

{

1057

{

1058

start_rt_bandwidth(&def_rt_bandwidth);

1058

start_rt_bandwidth(&def_rt_bandwidth);

1059

}

1059

}

1060

1061

static inline

1061

static inline

1062

void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}

1062

void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}

1063

1064

#endif /* CONFIG_RT_GROUP_SCHED */

1064

#endif /* CONFIG_RT_GROUP_SCHED */

1065

1066

static inline

1066

static inline

1067

void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1067

void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1068

{

1068

{

1069

int prio = rt_se_prio(rt_se);

1069

int prio = rt_se_prio(rt_se);

1070

1071

WARN_ON(!rt_prio(prio));

1071

WARN_ON(!rt_prio(prio));

1072

rt_rq->rt_nr_running++;

1072

rt_rq->rt_nr_running++;

1073

1074

inc_rt_prio(rt_rq, prio);

1074

inc_rt_prio(rt_rq, prio);

1075

inc_rt_migration(rt_se, rt_rq);

1075

inc_rt_migration(rt_se, rt_rq);

1076

inc_rt_group(rt_se, rt_rq);

1076

inc_rt_group(rt_se, rt_rq);

1077

}

1077

}

1078

1079

static inline

1079

static inline

1080

void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1080

void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)

1081

{

1081

{

1082

WARN_ON(!rt_prio(rt_se_prio(rt_se)));

1082

WARN_ON(!rt_prio(rt_se_prio(rt_se)));

1083

WARN_ON(!rt_rq->rt_nr_running);

1083

WARN_ON(!rt_rq->rt_nr_running);

1084

rt_rq->rt_nr_running--;

1084

rt_rq->rt_nr_running--;

1085

1086

dec_rt_prio(rt_rq, rt_se_prio(rt_se));

1086

dec_rt_prio(rt_rq, rt_se_prio(rt_se));

1087

dec_rt_migration(rt_se, rt_rq);

1087

dec_rt_migration(rt_se, rt_rq);

1088

dec_rt_group(rt_se, rt_rq);

1088

dec_rt_group(rt_se, rt_rq);

1089

}

1089

}

1090

1091

static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

1091

static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

1092

{

1092

{

1093

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

1093

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

1094

struct rt_prio_array *array = &rt_rq->active;

1094

struct rt_prio_array *array = &rt_rq->active;

1095

struct rt_rq *group_rq = group_rt_rq(rt_se);

1095

struct rt_rq *group_rq = group_rt_rq(rt_se);

1096

struct list_head *queue = array->queue + rt_se_prio(rt_se);

1096

struct list_head *queue = array->queue + rt_se_prio(rt_se);

1097

1098

/*

1098

/*

1099

* Don't enqueue the group if its throttled, or when empty.

1099

* Don't enqueue the group if its throttled, or when empty.

1100

* The latter is a consequence of the former when a child group

1100

* The latter is a consequence of the former when a child group

1101

* get throttled and the current group doesn't have any other

1101

* get throttled and the current group doesn't have any other

1102

* active members.

1102

* active members.

1103

*/

1103

*/

1104

if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))

1104

if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))

1105

return;

1105

return;

1106

1107

if (!rt_rq->rt_nr_running)

1107

if (!rt_rq->rt_nr_running)

1108

list_add_leaf_rt_rq(rt_rq);

1108

list_add_leaf_rt_rq(rt_rq);

1109

1110

if (head)

1110

if (head)

1111

list_add(&rt_se->run_list, queue);

1111

list_add(&rt_se->run_list, queue);

1112

else

1112

else

1113

list_add_tail(&rt_se->run_list, queue);

1113

list_add_tail(&rt_se->run_list, queue);

1114

__set_bit(rt_se_prio(rt_se), array->bitmap);

1114

__set_bit(rt_se_prio(rt_se), array->bitmap);

1115

1116

inc_rt_tasks(rt_se, rt_rq);

1116

inc_rt_tasks(rt_se, rt_rq);

1117

}

1117

}

1118

1119

static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)

1119

static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)

1120

{

1120

{

1121

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

1121

struct rt_rq *rt_rq = rt_rq_of_se(rt_se);

1122

struct rt_prio_array *array = &rt_rq->active;

1122

struct rt_prio_array *array = &rt_rq->active;

1123

1124

list_del_init(&rt_se->run_list);

1124

list_del_init(&rt_se->run_list);

1125

if (list_empty(array->queue + rt_se_prio(rt_se)))

1125

if (list_empty(array->queue + rt_se_prio(rt_se)))

1126

__clear_bit(rt_se_prio(rt_se), array->bitmap);

1126

__clear_bit(rt_se_prio(rt_se), array->bitmap);

1127

1128

dec_rt_tasks(rt_se, rt_rq);

1128

dec_rt_tasks(rt_se, rt_rq);

1129

if (!rt_rq->rt_nr_running)

1129

if (!rt_rq->rt_nr_running)

1130

list_del_leaf_rt_rq(rt_rq);

1130

list_del_leaf_rt_rq(rt_rq);

1131

}

1131

}

1132

1133

/*

1133

/*

1134

* Because the prio of an upper entry depends on the lower

1134

* Because the prio of an upper entry depends on the lower

1135

* entries, we must remove entries top - down.

1135

* entries, we must remove entries top - down.

1136

*/

1136

*/

1137

static void dequeue_rt_stack(struct sched_rt_entity *rt_se)

1137

static void dequeue_rt_stack(struct sched_rt_entity *rt_se)

1138

{

1138

{

1139

struct sched_rt_entity *back = NULL;

1139

struct sched_rt_entity *back = NULL;

1140

1141

for_each_sched_rt_entity(rt_se) {

1141

for_each_sched_rt_entity(rt_se) {

1142

rt_se->back = back;

1142

rt_se->back = back;

1143

back = rt_se;

1143

back = rt_se;

1144

}

1144

}

1145

1146

for (rt_se = back; rt_se; rt_se = rt_se->back) {

1146

for (rt_se = back; rt_se; rt_se = rt_se->back) {

1147

if (on_rt_rq(rt_se))

1147

if (on_rt_rq(rt_se))

1148

__dequeue_rt_entity(rt_se);

1148

__dequeue_rt_entity(rt_se);

1149

}

1149

}

1150

}

1150

}

1151

1152

static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

1152

static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)

1153

{

1153

{

1154

dequeue_rt_stack(rt_se);

1154

dequeue_rt_stack(rt_se);

1155

for_each_sched_rt_entity(rt_se)

1155

for_each_sched_rt_entity(rt_se)

1156

__enqueue_rt_entity(rt_se, head);

1156

__enqueue_rt_entity(rt_se, head);

1157

}

1157

}

1158

1159

static void dequeue_rt_entity(struct sched_rt_entity *rt_se)

1159

static void dequeue_rt_entity(struct sched_rt_entity *rt_se)

1160

{

1160

{

1161

dequeue_rt_stack(rt_se);

1161

dequeue_rt_stack(rt_se);

1162

1163

for_each_sched_rt_entity(rt_se) {

1163

for_each_sched_rt_entity(rt_se) {

1164

struct rt_rq *rt_rq = group_rt_rq(rt_se);

1164

struct rt_rq *rt_rq = group_rt_rq(rt_se);

1165

1166

if (rt_rq && rt_rq->rt_nr_running)

1166

if (rt_rq && rt_rq->rt_nr_running)

1167

__enqueue_rt_entity(rt_se, false);

1167

__enqueue_rt_entity(rt_se, false);

1168

}

1168

}

1169

}

1169

}

1170

1171

/*

1171

/*

1172

* Adding/removing a task to/from a priority array:

1172

* Adding/removing a task to/from a priority array:

1173

*/

1173

*/

1174

static void

1174

static void

1175

enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)

1175

enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)

1176

{

1176

{

1177

struct sched_rt_entity *rt_se = &p->rt;

1177

struct sched_rt_entity *rt_se = &p->rt;

1178

1179

if (flags & ENQUEUE_WAKEUP)

1179

if (flags & ENQUEUE_WAKEUP)

1180

rt_se->timeout = 0;

1180

rt_se->timeout = 0;

1181

1182

enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);

1182

enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);

1183

1184

if (!task_current(rq, p) && p->nr_cpus_allowed > 1)

1184

if (!task_current(rq, p) && p->nr_cpus_allowed > 1)

1185

enqueue_pushable_task(rq, p);

1185

enqueue_pushable_task(rq, p);

1186

1187

inc_nr_running(rq);

1187

inc_nr_running(rq);

1188

}

1188

}

1189

1190

static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)

1190

static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)

1191

{

1191

{

1192

struct sched_rt_entity *rt_se = &p->rt;

1192

struct sched_rt_entity *rt_se = &p->rt;

1193

1194

update_curr_rt(rq);

1194

update_curr_rt(rq);

1195

dequeue_rt_entity(rt_se);

1195

dequeue_rt_entity(rt_se);

1196

1197

dequeue_pushable_task(rq, p);

1197

dequeue_pushable_task(rq, p);

1198

1199

dec_nr_running(rq);

1199

dec_nr_running(rq);

1200

}

1200

}

1201

1202

/*

1202

/*

1203

* Put task to the head or the end of the run list without the overhead of

1203

* Put task to the head or the end of the run list without the overhead of

1204

* dequeue followed by enqueue.

1204

* dequeue followed by enqueue.

1205

*/

1205

*/

1206

static void

1206

static void

1207

requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)

1207

requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)

1208

{

1208

{

1209

if (on_rt_rq(rt_se)) {

1209

if (on_rt_rq(rt_se)) {

1210

struct rt_prio_array *array = &rt_rq->active;

1210

struct rt_prio_array *array = &rt_rq->active;

1211

struct list_head *queue = array->queue + rt_se_prio(rt_se);

1211

struct list_head *queue = array->queue + rt_se_prio(rt_se);

1212

1213

if (head)

1213

if (head)

1214

list_move(&rt_se->run_list, queue);

1214

list_move(&rt_se->run_list, queue);

1215

else

1215

else

1216

list_move_tail(&rt_se->run_list, queue);

1216

list_move_tail(&rt_se->run_list, queue);

1217

}

1217

}

1218

}

1218

}

1219

1220

static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)

1220

static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)

1221

{

1221

{

1222

struct sched_rt_entity *rt_se = &p->rt;

1222

struct sched_rt_entity *rt_se = &p->rt;

1223

struct rt_rq *rt_rq;

1223

struct rt_rq *rt_rq;

1224

1225

for_each_sched_rt_entity(rt_se) {

1225

for_each_sched_rt_entity(rt_se) {

1226

rt_rq = rt_rq_of_se(rt_se);

1226

rt_rq = rt_rq_of_se(rt_se);

1227

requeue_rt_entity(rt_rq, rt_se, head);

1227

requeue_rt_entity(rt_rq, rt_se, head);

1228

}

1228

}

1229

}

1229

}

1230

1231

static void yield_task_rt(struct rq *rq)

1231

static void yield_task_rt(struct rq *rq)

1232

{

1232

{

1233

requeue_task_rt(rq, rq->curr, 0);

1233

requeue_task_rt(rq, rq->curr, 0);

1234

}

1234

}

1235

1236

#ifdef CONFIG_SMP

1236

#ifdef CONFIG_SMP

1237

static int find_lowest_rq(struct task_struct *task);

1237

static int find_lowest_rq(struct task_struct *task);

1238

1239

static int

1239

static int

1240

select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)

1240

select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)

1241

{

1241

{

1242

struct task_struct *curr;

1242

struct task_struct *curr;

1243

struct rq *rq;

1243

struct rq *rq;

1244

int cpu;

1244

int cpu;

1245

1246

cpu = task_cpu(p);

1246

cpu = task_cpu(p);

1247

1248

if (p->nr_cpus_allowed == 1)

1248

if (p->nr_cpus_allowed == 1)

1249

goto out;

1249

goto out;

1250

1251

/* For anything but wake ups, just return the task_cpu */

1251

/* For anything but wake ups, just return the task_cpu */

1252

if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)

1252

if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)

1253

goto out;

1253

goto out;

1254

1255

rq = cpu_rq(cpu);

1255

rq = cpu_rq(cpu);

1256

1257

rcu_read_lock();

1257

rcu_read_lock();

1258

curr = ACCESS_ONCE(rq->curr); /* unlocked access */

1258

curr = ACCESS_ONCE(rq->curr); /* unlocked access */

1259

1260

/*

1260

/*

1261

* If the current task on @p's runqueue is an RT task, then

1261

* If the current task on @p's runqueue is an RT task, then

1262

* try to see if we can wake this RT task up on another

1262

* try to see if we can wake this RT task up on another

1263

* runqueue. Otherwise simply start this RT task

1263

* runqueue. Otherwise simply start this RT task

1264

* on its current runqueue.

1264

* on its current runqueue.

1265

*

1265

*

1266

* We want to avoid overloading runqueues. If the woken

1266

* We want to avoid overloading runqueues. If the woken

1267

* task is a higher priority, then it will stay on this CPU

1267

* task is a higher priority, then it will stay on this CPU

1268

* and the lower prio task should be moved to another CPU.

1268

* and the lower prio task should be moved to another CPU.

1269

* Even though this will probably make the lower prio task

1269

* Even though this will probably make the lower prio task

1270

* lose its cache, we do not want to bounce a higher task

1270

* lose its cache, we do not want to bounce a higher task

1271

* around just because it gave up its CPU, perhaps for a

1271

* around just because it gave up its CPU, perhaps for a

1272

* lock?

1272

* lock?

1273

*

1273

*

1274

* For equal prio tasks, we just let the scheduler sort it out.

1274

* For equal prio tasks, we just let the scheduler sort it out.

1275

*

1275

*

1276

* Otherwise, just let it ride on the affined RQ and the

1276

* Otherwise, just let it ride on the affined RQ and the

1277

* post-schedule router will push the preempted task away

1277

* post-schedule router will push the preempted task away

1278

*

1278

*

1279

* This test is optimistic, if we get it wrong the load-balancer

1279

* This test is optimistic, if we get it wrong the load-balancer

1280

* will have to sort it out.

1280

* will have to sort it out.

1281

*/

1281

*/

1282

if (curr && unlikely(rt_task(curr)) &&

1282

if (curr && unlikely(rt_task(curr)) &&

1283

(curr->nr_cpus_allowed < 2 ||

1283

(curr->nr_cpus_allowed < 2 ||

1284

curr->prio <= p->prio) &&

1284

curr->prio <= p->prio) &&

1285

(p->nr_cpus_allowed > 1)) {

1285

(p->nr_cpus_allowed > 1)) {

1286

int target = find_lowest_rq(p);

1286

int target = find_lowest_rq(p);

1287

1288

if (target != -1)

1288

if (target != -1)

1289

cpu = target;

1289

cpu = target;

1290

}

1290

}

1291

rcu_read_unlock();

1291

rcu_read_unlock();

1292

1293

out:

1293

out:

1294

return cpu;

1294

return cpu;

1295

}

1295

}

1296

1297

static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)

1297

static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)

1298

{

1298

{

1299

if (rq->curr->nr_cpus_allowed == 1)

1299

if (rq->curr->nr_cpus_allowed == 1)

1300

return;

1300

return;

1301

1302

if (p->nr_cpus_allowed != 1

1302

if (p->nr_cpus_allowed != 1

1303

&& cpupri_find(&rq->rd->cpupri, p, NULL))

1303

&& cpupri_find(&rq->rd->cpupri, p, NULL))

1304

return;

1304

return;

1305

1306

if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))

1306

if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))

1307

return;

1307

return;

1308

1309

/*

1309

/*

1310

* There appears to be other cpus that can accept

1310

* There appears to be other cpus that can accept

1311

* current and none to run 'p', so lets reschedule

1311

* current and none to run 'p', so lets reschedule

1312

* to try and push current away:

1312

* to try and push current away:

1313

*/

1313

*/

1314

requeue_task_rt(rq, p, 1);

1314

requeue_task_rt(rq, p, 1);

1315

resched_task(rq->curr);

1315

resched_task(rq->curr);

1316

}

1316

}

1317

1318

#endif /* CONFIG_SMP */

1318

#endif /* CONFIG_SMP */

1319

1320

/*

1320

/*

1321

* Preempt the current task with a newly woken task if needed:

1321

* Preempt the current task with a newly woken task if needed:

1322

*/

1322

*/

1323

static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)

1323

static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)

1324

{

1324

{

1325

if (p->prio < rq->curr->prio) {

1325

if (p->prio < rq->curr->prio) {

1326

resched_task(rq->curr);

1326

resched_task(rq->curr);

1327

return;

1327

return;

1328

}

1328

}

1329

1330

#ifdef CONFIG_SMP

1330

#ifdef CONFIG_SMP

1331

/*

1331

/*

1332

* If:

1332

* If:

1333

*

1333

*

1334

* - the newly woken task is of equal priority to the current task

1334

* - the newly woken task is of equal priority to the current task

1335

* - the newly woken task is non-migratable while current is migratable

1335

* - the newly woken task is non-migratable while current is migratable

1336

* - current will be preempted on the next reschedule

1336

* - current will be preempted on the next reschedule

1337

*

1337

*

1338

* we should check to see if current can readily move to a different

1338

* we should check to see if current can readily move to a different

1339

* cpu. If so, we will reschedule to allow the push logic to try

1339

* cpu. If so, we will reschedule to allow the push logic to try

1340

* to move current somewhere else, making room for our non-migratable

1340

* to move current somewhere else, making room for our non-migratable

1341

* task.

1341

* task.

1342

*/

1342

*/

1343

if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))

1343

if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))

1344

check_preempt_equal_prio(rq, p);

1344

check_preempt_equal_prio(rq, p);

1345

#endif

1345

#endif

1346

}

1346

}

1347

1348

static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,

1348

static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,

1349

struct rt_rq *rt_rq)

1349

struct rt_rq *rt_rq)

1350

{

1350

{

1351

struct rt_prio_array *array = &rt_rq->active;

1351

struct rt_prio_array *array = &rt_rq->active;

1352

struct sched_rt_entity *next = NULL;

1352

struct sched_rt_entity *next = NULL;

1353

struct list_head *queue;

1353

struct list_head *queue;

1354

int idx;

1354

int idx;

1355

1356

idx = sched_find_first_bit(array->bitmap);

1356

idx = sched_find_first_bit(array->bitmap);

1357

BUG_ON(idx >= MAX_RT_PRIO);

1357

BUG_ON(idx >= MAX_RT_PRIO);

1358

1359

queue = array->queue + idx;

1359

queue = array->queue + idx;

1360

next = list_entry(queue->next, struct sched_rt_entity, run_list);

1360

next = list_entry(queue->next, struct sched_rt_entity, run_list);

1361

1362

return next;

1362

return next;

1363

}

1363

}

1364

1365

static struct task_struct *_pick_next_task_rt(struct rq *rq)

1365

static struct task_struct *_pick_next_task_rt(struct rq *rq)

1366

{

1366

{

1367

struct sched_rt_entity *rt_se;

1367

struct sched_rt_entity *rt_se;

1368

struct task_struct *p;

1368

struct task_struct *p;

1369

struct rt_rq *rt_rq;

1369

struct rt_rq *rt_rq;

1370

1371

rt_rq = &rq->rt;

1371

rt_rq = &rq->rt;

1372

1373

if (!rt_rq->rt_nr_running)

1373

if (!rt_rq->rt_nr_running)

1374

return NULL;

1374

return NULL;

1375

1376

if (rt_rq_throttled(rt_rq))

1376

if (rt_rq_throttled(rt_rq))

1377

return NULL;

1377

return NULL;

1378

1379

do {

1379

do {

1380

rt_se = pick_next_rt_entity(rq, rt_rq);

1380

rt_se = pick_next_rt_entity(rq, rt_rq);

1381

BUG_ON(!rt_se);

1381

BUG_ON(!rt_se);

1382

rt_rq = group_rt_rq(rt_se);

1382

rt_rq = group_rt_rq(rt_se);

1383

} while (rt_rq);

1383

} while (rt_rq);

1384

1385

p = rt_task_of(rt_se);

1385

p = rt_task_of(rt_se);

1386

p->se.exec_start = rq->clock_task;

1386

p->se.exec_start = rq->clock_task;

1387

1388

return p;

1388

return p;

1389

}

1389

}

1390

1391

static struct task_struct *pick_next_task_rt(struct rq *rq)

1391

static struct task_struct *pick_next_task_rt(struct rq *rq)

1392

{

1392

{

1393

struct task_struct *p = _pick_next_task_rt(rq);

1393

struct task_struct *p = _pick_next_task_rt(rq);

1394

1395

/* The running task is never eligible for pushing */

1395

/* The running task is never eligible for pushing */

1396

if (p)

1396

if (p)

1397

dequeue_pushable_task(rq, p);

1397

dequeue_pushable_task(rq, p);

1398

1399

#ifdef CONFIG_SMP

1399

#ifdef CONFIG_SMP

1400

/*

1400

/*

1401

* We detect this state here so that we can avoid taking the RQ

1401

* We detect this state here so that we can avoid taking the RQ

1402

* lock again later if there is no need to push

1402

* lock again later if there is no need to push

1403

*/

1403

*/

1404

rq->post_schedule = has_pushable_tasks(rq);

1404

rq->post_schedule = has_pushable_tasks(rq);

1405

#endif

1405

#endif

1406

1407

return p;

1407

return p;

1408

}

1408

}

1409

1410

static void put_prev_task_rt(struct rq *rq, struct task_struct *p)

1410

static void put_prev_task_rt(struct rq *rq, struct task_struct *p)

1411

{

1411

{

1412

update_curr_rt(rq);

1412

update_curr_rt(rq);

1413

1414

/*

1414

/*

1415

* The previous task needs to be made eligible for pushing

1415

* The previous task needs to be made eligible for pushing

1416

* if it is still active

1416

* if it is still active

1417

*/

1417

*/

1418

if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)

1418

if (on_rt_rq(&p->rt) && p->nr_cpus_allowed > 1)

1419

enqueue_pushable_task(rq, p);

1419

enqueue_pushable_task(rq, p);

1420

}

1420

}

1421

1422

#ifdef CONFIG_SMP

1422

#ifdef CONFIG_SMP

1423

1424

/* Only try algorithms three times */

1424

/* Only try algorithms three times */

1425

#define RT_MAX_TRIES 3

1425

#define RT_MAX_TRIES 3

1426

1427

static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)

1427

static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)

1428

{

1428

{

1429

if (!task_running(rq, p) &&

1429

if (!task_running(rq, p) &&

1430

(cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&

1430

(cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&

1431

(p->nr_cpus_allowed > 1))

1431

(p->nr_cpus_allowed > 1))

1432

return 1;

1432

return 1;

1433

return 0;

1433

return 0;

1434

}

1434

}

1435

1436

/* Return the second highest RT task, NULL otherwise */

1436

/* Return the second highest RT task, NULL otherwise */

1437

static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)

1437

static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)

1438

{

1438

{

1439

struct task_struct *next = NULL;

1439

struct task_struct *next = NULL;

1440

struct sched_rt_entity *rt_se;

1440

struct sched_rt_entity *rt_se;

1441

struct rt_prio_array *array;

1441

struct rt_prio_array *array;

1442

struct rt_rq *rt_rq;

1442

struct rt_rq *rt_rq;

1443

int idx;

1443

int idx;

1444

1445

for_each_leaf_rt_rq(rt_rq, rq) {

1445

for_each_leaf_rt_rq(rt_rq, rq) {

1446

array = &rt_rq->active;

1446

array = &rt_rq->active;

1447

idx = sched_find_first_bit(array->bitmap);

1447

idx = sched_find_first_bit(array->bitmap);

1448

next_idx:

1448

next_idx:

1449

if (idx >= MAX_RT_PRIO)

1449

if (idx >= MAX_RT_PRIO)

1450

continue;

1450

continue;

1451

if (next && next->prio <= idx)

1451

if (next && next->prio <= idx)

1452

continue;

1452

continue;

1453

list_for_each_entry(rt_se, array->queue + idx, run_list) {

1453

list_for_each_entry(rt_se, array->queue + idx, run_list) {

1454

struct task_struct *p;

1454

struct task_struct *p;

1455

1456

if (!rt_entity_is_task(rt_se))

1456

if (!rt_entity_is_task(rt_se))

1457

continue;

1457

continue;

1458

1459

p = rt_task_of(rt_se);

1459

p = rt_task_of(rt_se);

1460

if (pick_rt_task(rq, p, cpu)) {

1460

if (pick_rt_task(rq, p, cpu)) {

1461

next = p;

1461

next = p;

1462

break;

1462

break;

1463

}

1463

}

1464

}

1464

}

1465

if (!next) {

1465

if (!next) {

1466

idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);

1466

idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);

1467

goto next_idx;

1467

goto next_idx;

1468

}

1468

}

1469

}

1469

}

1470

1471

return next;

1471

return next;

1472

}

1472

}

1473

1474

static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);

1474

static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);

1475

1476

static int find_lowest_rq(struct task_struct *task)

1476

static int find_lowest_rq(struct task_struct *task)

1477

{

1477

{

1478

struct sched_domain *sd;

1478

struct sched_domain *sd;

1479

struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);

1479

struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);

1480

int this_cpu = smp_processor_id();

1480

int this_cpu = smp_processor_id();

1481

int cpu = task_cpu(task);

1481

int cpu = task_cpu(task);

1482

1483

/* Make sure the mask is initialized first */

1483

/* Make sure the mask is initialized first */

1484

if (unlikely(!lowest_mask))

1484

if (unlikely(!lowest_mask))

1485

return -1;

1485

return -1;

1486

1487

if (task->nr_cpus_allowed == 1)

1487

if (task->nr_cpus_allowed == 1)

1488

return -1; /* No other targets possible */

1488

return -1; /* No other targets possible */

1489

1490

if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))

1490

if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))

1491

return -1; /* No targets found */

1491

return -1; /* No targets found */

1492

1493

/*

1493

/*

1494

* At this point we have built a mask of cpus representing the

1494

* At this point we have built a mask of cpus representing the

1495

* lowest priority tasks in the system. Now we want to elect

1495

* lowest priority tasks in the system. Now we want to elect

1496

* the best one based on our affinity and topology.

1496

* the best one based on our affinity and topology.

1497

*

1497

*

1498

* We prioritize the last cpu that the task executed on since

1498

* We prioritize the last cpu that the task executed on since

1499

* it is most likely cache-hot in that location.

1499

* it is most likely cache-hot in that location.

1500

*/

1500

*/

1501

if (cpumask_test_cpu(cpu, lowest_mask))

1501

if (cpumask_test_cpu(cpu, lowest_mask))

1502

return cpu;

1502

return cpu;

1503

1504

/*

1504

/*

1505

* Otherwise, we consult the sched_domains span maps to figure

1505

* Otherwise, we consult the sched_domains span maps to figure

1506

* out which cpu is logically closest to our hot cache data.

1506

* out which cpu is logically closest to our hot cache data.

1507

*/

1507

*/

1508

if (!cpumask_test_cpu(this_cpu, lowest_mask))

1508

if (!cpumask_test_cpu(this_cpu, lowest_mask))

1509

this_cpu = -1; /* Skip this_cpu opt if not among lowest */

1509

this_cpu = -1; /* Skip this_cpu opt if not among lowest */

1510

1511

rcu_read_lock();

1511

rcu_read_lock();

1512

for_each_domain(cpu, sd) {

1512

for_each_domain(cpu, sd) {

1513

if (sd->flags & SD_WAKE_AFFINE) {

1513

if (sd->flags & SD_WAKE_AFFINE) {

1514

int best_cpu;

1514

int best_cpu;

1515

1516

/*

1516

/*

1517

* "this_cpu" is cheaper to preempt than a

1517

* "this_cpu" is cheaper to preempt than a

1518

* remote processor.

1518

* remote processor.

1519

*/

1519

*/

1520

if (this_cpu != -1 &&

1520

if (this_cpu != -1 &&

1521

cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {

1521

cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {

1522

rcu_read_unlock();

1522

rcu_read_unlock();

1523

return this_cpu;

1523

return this_cpu;

1524

}

1524

}

1525

1526

best_cpu = cpumask_first_and(lowest_mask,

1526

best_cpu = cpumask_first_and(lowest_mask,

1527

sched_domain_span(sd));

1527

sched_domain_span(sd));

1528

if (best_cpu < nr_cpu_ids) {

1528

if (best_cpu < nr_cpu_ids) {

1529

rcu_read_unlock();

1529

rcu_read_unlock();

1530

return best_cpu;

1530

return best_cpu;

1531

}

1531

}

1532

}

1532

}

1533

}

1533

}

1534

rcu_read_unlock();

1534

rcu_read_unlock();

1535

1536

/*

1536

/*

1537

* And finally, if there were no matches within the domains

1537

* And finally, if there were no matches within the domains

1538

* just give the caller *something* to work with from the compatible

1538

* just give the caller *something* to work with from the compatible

1539

* locations.

1539

* locations.

1540

*/

1540

*/

1541

if (this_cpu != -1)

1541

if (this_cpu != -1)

1542

return this_cpu;

1542

return this_cpu;

1543

1544

cpu = cpumask_any(lowest_mask);

1544

cpu = cpumask_any(lowest_mask);

1545

if (cpu < nr_cpu_ids)

1545

if (cpu < nr_cpu_ids)

1546

return cpu;

1546

return cpu;

1547

return -1;

1547

return -1;

1548

}

1548

}

1549

1550

/* Will lock the rq it finds */

1550

/* Will lock the rq it finds */

1551

static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)

1551

static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)

1552

{

1552

{

1553

struct rq *lowest_rq = NULL;

1553

struct rq *lowest_rq = NULL;

1554

int tries;

1554

int tries;

1555

int cpu;

1555

int cpu;

1556

1557

for (tries = 0; tries < RT_MAX_TRIES; tries++) {

1557

for (tries = 0; tries < RT_MAX_TRIES; tries++) {

1558

cpu = find_lowest_rq(task);

1558

cpu = find_lowest_rq(task);

1559

1560

if ((cpu == -1) || (cpu == rq->cpu))

1560

if ((cpu == -1) || (cpu == rq->cpu))

1561

break;

1561

break;

1562

1563

lowest_rq = cpu_rq(cpu);

1563

lowest_rq = cpu_rq(cpu);

1564

1565

/* if the prio of this runqueue changed, try again */

1565

/* if the prio of this runqueue changed, try again */

1566

if (double_lock_balance(rq, lowest_rq)) {

1566

if (double_lock_balance(rq, lowest_rq)) {

1567

/*

1567

/*

1568

* We had to unlock the run queue. In

1568

* We had to unlock the run queue. In

1569

* the mean time, task could have

1569

* the mean time, task could have

1570

* migrated already or had its affinity changed.

1570

* migrated already or had its affinity changed.

1571

* Also make sure that it wasn't scheduled on its rq.

1571

* Also make sure that it wasn't scheduled on its rq.

1572

*/

1572

*/

1573

if (unlikely(task_rq(task) != rq ||

1573

if (unlikely(task_rq(task) != rq ||

1574

!cpumask_test_cpu(lowest_rq->cpu,

1574

!cpumask_test_cpu(lowest_rq->cpu,

1575

tsk_cpus_allowed(task)) ||

1575

tsk_cpus_allowed(task)) ||

1576

task_running(rq, task) ||

1576

task_running(rq, task) ||

1577

!task->on_rq)) {

1577

!task->on_rq)) {

1578

1579

double_unlock_balance(rq, lowest_rq);

1579

double_unlock_balance(rq, lowest_rq);

1580

lowest_rq = NULL;

1580

lowest_rq = NULL;

1581

break;

1581

break;

1582

}

1582

}

1583

}

1583

}

1584

1585

/* If this rq is still suitable use it. */

1585

/* If this rq is still suitable use it. */

1586

if (lowest_rq->rt.highest_prio.curr > task->prio)

1586

if (lowest_rq->rt.highest_prio.curr > task->prio)

1587

break;

1587

break;

1588

1589

/* try again */

1589

/* try again */

1590

double_unlock_balance(rq, lowest_rq);

1590

double_unlock_balance(rq, lowest_rq);

1591

lowest_rq = NULL;

1591

lowest_rq = NULL;

1592

}

1592

}

1593

1594

return lowest_rq;

1594

return lowest_rq;

1595

}

1595

}

1596

1597

static struct task_struct *pick_next_pushable_task(struct rq *rq)

1597

static struct task_struct *pick_next_pushable_task(struct rq *rq)

1598

{

1598

{

1599

struct task_struct *p;

1599

struct task_struct *p;

1600

1601

if (!has_pushable_tasks(rq))

1601

if (!has_pushable_tasks(rq))

1602

return NULL;

1602

return NULL;

1603

1604

p = plist_first_entry(&rq->rt.pushable_tasks,

1604

p = plist_first_entry(&rq->rt.pushable_tasks,

1605

struct task_struct, pushable_tasks);

1605

struct task_struct, pushable_tasks);

1606

1607

BUG_ON(rq->cpu != task_cpu(p));

1607

BUG_ON(rq->cpu != task_cpu(p));

1608

BUG_ON(task_current(rq, p));

1608

BUG_ON(task_current(rq, p));

1609

BUG_ON(p->nr_cpus_allowed <= 1);

1609

BUG_ON(p->nr_cpus_allowed <= 1);

1610

1611

BUG_ON(!p->on_rq);

1611

BUG_ON(!p->on_rq);

1612

BUG_ON(!rt_task(p));

1612

BUG_ON(!rt_task(p));

1613

1614

return p;

1614

return p;

1615

}

1615

}

1616

1617

/*

1617

/*

1618

* If the current CPU has more than one RT task, see if the non

1618

* If the current CPU has more than one RT task, see if the non

1619

* running task can migrate over to a CPU that is running a task

1619

* running task can migrate over to a CPU that is running a task

1620

* of lesser priority.

1620

* of lesser priority.

1621

*/

1621

*/

1622

static int push_rt_task(struct rq *rq)

1622

static int push_rt_task(struct rq *rq)

1623

{

1623

{

1624

struct task_struct *next_task;

1624

struct task_struct *next_task;

1625

struct rq *lowest_rq;

1625

struct rq *lowest_rq;

1626

int ret = 0;

1626

int ret = 0;

1627

1628

if (!rq->rt.overloaded)

1628

if (!rq->rt.overloaded)

1629

return 0;

1629

return 0;

1630

1631

next_task = pick_next_pushable_task(rq);

1631

next_task = pick_next_pushable_task(rq);

1632

if (!next_task)

1632

if (!next_task)

1633

return 0;

1633

return 0;

1634

1635

retry:

1635

retry:

1636

if (unlikely(next_task == rq->curr)) {

1636

if (unlikely(next_task == rq->curr)) {

1637

WARN_ON(1);

1637

WARN_ON(1);

1638

return 0;

1638

return 0;

1639

}

1639

}

1640

1641

/*

1641

/*

1642

* It's possible that the next_task slipped in of

1642

* It's possible that the next_task slipped in of

1643

* higher priority than current. If that's the case

1643

* higher priority than current. If that's the case

1644

* just reschedule current.

1644

* just reschedule current.

1645

*/

1645

*/

1646

if (unlikely(next_task->prio < rq->curr->prio)) {

1646

if (unlikely(next_task->prio < rq->curr->prio)) {

1647

resched_task(rq->curr);

1647

resched_task(rq->curr);

1648

return 0;

1648

return 0;

1649

}

1649

}

1650

1651

/* We might release rq lock */

1651

/* We might release rq lock */

1652

get_task_struct(next_task);

1652

get_task_struct(next_task);

1653

1654

/* find_lock_lowest_rq locks the rq if found */

1654

/* find_lock_lowest_rq locks the rq if found */

1655

lowest_rq = find_lock_lowest_rq(next_task, rq);

1655

lowest_rq = find_lock_lowest_rq(next_task, rq);

1656

if (!lowest_rq) {

1656

if (!lowest_rq) {

1657

struct task_struct *task;

1657

struct task_struct *task;

1658

/*

1658

/*

1659

* find_lock_lowest_rq releases rq->lock

1659

* find_lock_lowest_rq releases rq->lock

1660

* so it is possible that next_task has migrated.

1660

* so it is possible that next_task has migrated.

1661

*

1661

*

1662

* We need to make sure that the task is still on the same

1662

* We need to make sure that the task is still on the same

1663

* run-queue and is also still the next task eligible for

1663

* run-queue and is also still the next task eligible for

1664

* pushing.

1664

* pushing.

1665

*/

1665

*/

1666

task = pick_next_pushable_task(rq);

1666

task = pick_next_pushable_task(rq);

1667

if (task_cpu(next_task) == rq->cpu && task == next_task) {

1667

if (task_cpu(next_task) == rq->cpu && task == next_task) {

1668

/*

1668

/*

1669

* The task hasn't migrated, and is still the next

1669

* The task hasn't migrated, and is still the next

1670

* eligible task, but we failed to find a run-queue

1670

* eligible task, but we failed to find a run-queue

1671

* to push it to. Do not retry in this case, since

1671

* to push it to. Do not retry in this case, since

1672

* other cpus will pull from us when ready.

1672

* other cpus will pull from us when ready.

1673

*/

1673

*/

1674

goto out;

1674

goto out;

1675

}

1675

}

1676

1677

if (!task)

1677

if (!task)

1678

/* No more tasks, just exit */

1678

/* No more tasks, just exit */

1679

goto out;

1679

goto out;

1680

1681

/*

1681

/*

1682

* Something has shifted, try again.

1682

* Something has shifted, try again.

1683

*/

1683

*/

1684

put_task_struct(next_task);

1684

put_task_struct(next_task);

1685

next_task = task;

1685

next_task = task;

1686

goto retry;

1686

goto retry;

1687

}

1687

}

1688

1689

deactivate_task(rq, next_task, 0);

1689

deactivate_task(rq, next_task, 0);

1690

set_task_cpu(next_task, lowest_rq->cpu);

1690

set_task_cpu(next_task, lowest_rq->cpu);

1691

activate_task(lowest_rq, next_task, 0);

1691

activate_task(lowest_rq, next_task, 0);

1692

ret = 1;

1692

ret = 1;

1693

1694

resched_task(lowest_rq->curr);

1694

resched_task(lowest_rq->curr);

1695

1696

double_unlock_balance(rq, lowest_rq);

1696

double_unlock_balance(rq, lowest_rq);

1697

1698

out:

1698

out:

1699

put_task_struct(next_task);

1699

put_task_struct(next_task);

1700

1701

return ret;

1701

return ret;

1702

}

1702

}

1703

1704

static void push_rt_tasks(struct rq *rq)

1704

static void push_rt_tasks(struct rq *rq)

1705

{

1705

{

1706

/* push_rt_task will return true if it moved an RT */

1706

/* push_rt_task will return true if it moved an RT */

1707

while (push_rt_task(rq))

1707

while (push_rt_task(rq))

1708

;

1708

;

1709

}

1709

}

1710

1711

static int pull_rt_task(struct rq *this_rq)

1711

static int pull_rt_task(struct rq *this_rq)

1712

{

1712

{

1713

int this_cpu = this_rq->cpu, ret = 0, cpu;

1713

int this_cpu = this_rq->cpu, ret = 0, cpu;

1714

struct task_struct *p;

1714

struct task_struct *p;

1715

struct rq *src_rq;

1715

struct rq *src_rq;

1716

1717

if (likely(!rt_overloaded(this_rq)))

1717

if (likely(!rt_overloaded(this_rq)))

1718

return 0;

1718

return 0;

1719

1720

for_each_cpu(cpu, this_rq->rd->rto_mask) {

1720

for_each_cpu(cpu, this_rq->rd->rto_mask) {

1721

if (this_cpu == cpu)

1721

if (this_cpu == cpu)

1722

continue;

1722

continue;

1723

1724

src_rq = cpu_rq(cpu);

1724

src_rq = cpu_rq(cpu);

1725

1726

/*

1726

/*

1727

* Don't bother taking the src_rq->lock if the next highest

1727

* Don't bother taking the src_rq->lock if the next highest

1728

* task is known to be lower-priority than our current task.

1728

* task is known to be lower-priority than our current task.

1729

* This may look racy, but if this value is about to go

1729

* This may look racy, but if this value is about to go

1730

* logically higher, the src_rq will push this task away.

1730

* logically higher, the src_rq will push this task away.

1731

* And if its going logically lower, we do not care

1731

* And if its going logically lower, we do not care

1732

*/

1732

*/

1733

if (src_rq->rt.highest_prio.next >=

1733

if (src_rq->rt.highest_prio.next >=

1734

this_rq->rt.highest_prio.curr)

1734

this_rq->rt.highest_prio.curr)

1735

continue;

1735

continue;

1736

1737

/*

1737

/*

1738

* We can potentially drop this_rq's lock in

1738

* We can potentially drop this_rq's lock in

1739

* double_lock_balance, and another CPU could

1739

* double_lock_balance, and another CPU could

1740

* alter this_rq

1740

* alter this_rq

1741

*/

1741

*/

1742

double_lock_balance(this_rq, src_rq);

1742

double_lock_balance(this_rq, src_rq);

1743

1744

/*

1744

/*

1745

* Are there still pullable RT tasks?

1745

* Are there still pullable RT tasks?

1746

*/

1746

*/

1747

if (src_rq->rt.rt_nr_running <= 1)

1747

if (src_rq->rt.rt_nr_running <= 1)

1748

goto skip;

1748

goto skip;

1749

1750

p = pick_next_highest_task_rt(src_rq, this_cpu);

1750

p = pick_next_highest_task_rt(src_rq, this_cpu);

1751

1752

/*

1752

/*

1753

* Do we have an RT task that preempts

1753

* Do we have an RT task that preempts

1754

* the to-be-scheduled task?

1754

* the to-be-scheduled task?

1755

*/

1755

*/

1756

if (p && (p->prio < this_rq->rt.highest_prio.curr)) {

1756

if (p && (p->prio < this_rq->rt.highest_prio.curr)) {

1757

WARN_ON(p == src_rq->curr);

1757

WARN_ON(p == src_rq->curr);

1758

WARN_ON(!p->on_rq);

1758

WARN_ON(!p->on_rq);

1759

1760

/*

1760

/*

1761

* There's a chance that p is higher in priority

1761

* There's a chance that p is higher in priority

1762

* than what's currently running on its cpu.

1762

* than what's currently running on its cpu.

1763

* This is just that p is wakeing up and hasn't

1763

* This is just that p is wakeing up and hasn't

1764

* had a chance to schedule. We only pull

1764

* had a chance to schedule. We only pull

1765

* p if it is lower in priority than the

1765

* p if it is lower in priority than the

1766

* current task on the run queue

1766

* current task on the run queue

1767

*/

1767

*/

1768

if (p->prio < src_rq->curr->prio)

1768

if (p->prio < src_rq->curr->prio)

1769

goto skip;

1769

goto skip;

1770

1771

ret = 1;

1771

ret = 1;

1772

1773

deactivate_task(src_rq, p, 0);

1773

deactivate_task(src_rq, p, 0);

1774

set_task_cpu(p, this_cpu);

1774

set_task_cpu(p, this_cpu);

1775

activate_task(this_rq, p, 0);

1775

activate_task(this_rq, p, 0);

1776

/*

1776

/*

1777

* We continue with the search, just in

1777

* We continue with the search, just in

1778

* case there's an even higher prio task

1778

* case there's an even higher prio task

1779

* in another runqueue. (low likelihood

1779

* in another runqueue. (low likelihood

1780

* but possible)

1780

* but possible)

1781

*/

1781

*/

1782

}

1782

}

1783

skip:

1783

skip:

1784

double_unlock_balance(this_rq, src_rq);

1784

double_unlock_balance(this_rq, src_rq);

1785

}

1785

}

1786

1787

return ret;

1787

return ret;

1788

}

1788

}

1789

1790

static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)

1790

static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)

1791

{

1791

{

1792

/* Try to pull RT tasks here if we lower this rq's prio */

1792

/* Try to pull RT tasks here if we lower this rq's prio */

1793

if (rq->rt.highest_prio.curr > prev->prio)

1793

if (rq->rt.highest_prio.curr > prev->prio)

1794

pull_rt_task(rq);

1794

pull_rt_task(rq);

1795

}

1795

}

1796

1797

static void post_schedule_rt(struct rq *rq)

1797

static void post_schedule_rt(struct rq *rq)

1798

{

1798

{

1799

push_rt_tasks(rq);

1799

push_rt_tasks(rq);

1800

}

1800

}

1801

1802

/*

1802

/*

1803

* If we are not running and we are not going to reschedule soon, we should

1803

* If we are not running and we are not going to reschedule soon, we should

1804

* try to push tasks away now

1804

* try to push tasks away now

1805

*/

1805

*/

1806

static void task_woken_rt(struct rq *rq, struct task_struct *p)

1806

static void task_woken_rt(struct rq *rq, struct task_struct *p)

1807

{

1807

{

1808

if (!task_running(rq, p) &&

1808

if (!task_running(rq, p) &&

1809

!test_tsk_need_resched(rq->curr) &&

1809

!test_tsk_need_resched(rq->curr) &&

1810

has_pushable_tasks(rq) &&

1810

has_pushable_tasks(rq) &&

1811

p->nr_cpus_allowed > 1 &&

1811

p->nr_cpus_allowed > 1 &&

1812

rt_task(rq->curr) &&

1812

rt_task(rq->curr) &&

1813

(rq->curr->nr_cpus_allowed < 2 ||

1813

(rq->curr->nr_cpus_allowed < 2 ||

1814

rq->curr->prio <= p->prio))

1814

rq->curr->prio <= p->prio))

1815

push_rt_tasks(rq);

1815

push_rt_tasks(rq);

1816

}

1816

}

1817

1818

static void set_cpus_allowed_rt(struct task_struct *p,

1818

static void set_cpus_allowed_rt(struct task_struct *p,

1819

const struct cpumask *new_mask)

1819

const struct cpumask *new_mask)

1820

{

1820

{

1821

struct rq *rq;

1821

struct rq *rq;

1822

int weight;

1822

int weight;

1823

1824

BUG_ON(!rt_task(p));

1824

BUG_ON(!rt_task(p));

1825

1826

if (!p->on_rq)

1826

if (!p->on_rq)

1827

return;

1827

return;

1828

1829

weight = cpumask_weight(new_mask);

1829

weight = cpumask_weight(new_mask);

1830

1831

/*

1831

/*

1832

* Only update if the process changes its state from whether it

1832

* Only update if the process changes its state from whether it

1833

* can migrate or not.

1833

* can migrate or not.

1834

*/

1834

*/

1835

if ((p->nr_cpus_allowed > 1) == (weight > 1))

1835

if ((p->nr_cpus_allowed > 1) == (weight > 1))

1836

return;

1836

return;

1837

1838

rq = task_rq(p);

1838

rq = task_rq(p);

1839

1840

/*

1840

/*

1841

* The process used to be able to migrate OR it can now migrate

1841

* The process used to be able to migrate OR it can now migrate

1842

*/

1842

*/

1843

if (weight <= 1) {

1843

if (weight <= 1) {

1844

if (!task_current(rq, p))

1844

if (!task_current(rq, p))

1845

dequeue_pushable_task(rq, p);

1845

dequeue_pushable_task(rq, p);

1846

BUG_ON(!rq->rt.rt_nr_migratory);

1846

BUG_ON(!rq->rt.rt_nr_migratory);

1847

rq->rt.rt_nr_migratory--;

1847

rq->rt.rt_nr_migratory--;

1848

} else {

1848

} else {

1849

if (!task_current(rq, p))

1849

if (!task_current(rq, p))

1850

enqueue_pushable_task(rq, p);

1850

enqueue_pushable_task(rq, p);

1851

rq->rt.rt_nr_migratory++;

1851

rq->rt.rt_nr_migratory++;

1852

}

1852

}

1853

1854

update_rt_migration(&rq->rt);

1854

update_rt_migration(&rq->rt);

1855

}

1855

}

1856

1857

/* Assumes rq->lock is held */

1857

/* Assumes rq->lock is held */

1858

static void rq_online_rt(struct rq *rq)

1858

static void rq_online_rt(struct rq *rq)

1859

{

1859

{

1860

if (rq->rt.overloaded)

1860

if (rq->rt.overloaded)

1861

rt_set_overload(rq);

1861

rt_set_overload(rq);

1862

1863

__enable_runtime(rq);

1863

__enable_runtime(rq);

1864

1865

cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);

1865

cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);

1866

}

1866

}

1867

1868

/* Assumes rq->lock is held */

1868

/* Assumes rq->lock is held */

1869

static void rq_offline_rt(struct rq *rq)

1869

static void rq_offline_rt(struct rq *rq)

1870

{

1870

{

1871

if (rq->rt.overloaded)

1871

if (rq->rt.overloaded)

1872

rt_clear_overload(rq);

1872

rt_clear_overload(rq);

1873

1874

__disable_runtime(rq);

1874

__disable_runtime(rq);

1875

1876

cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);

1876

cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);

1877

}

1877

}

1878

1879

/*

1879

/*

1880

* When switch from the rt queue, we bring ourselves to a position

1880

* When switch from the rt queue, we bring ourselves to a position

1881

* that we might want to pull RT tasks from other runqueues.

1881

* that we might want to pull RT tasks from other runqueues.

1882

*/

1882

*/

1883

static void switched_from_rt(struct rq *rq, struct task_struct *p)

1883

static void switched_from_rt(struct rq *rq, struct task_struct *p)

1884

{

1884

{

1885

/*

1885

/*

1886

* If there are other RT tasks then we will reschedule

1886

* If there are other RT tasks then we will reschedule

1887

* and the scheduling of the other RT tasks will handle

1887

* and the scheduling of the other RT tasks will handle

1888

* the balancing. But if we are the last RT task

1888

* the balancing. But if we are the last RT task

1889

* we may need to handle the pulling of RT tasks

1889

* we may need to handle the pulling of RT tasks

1890

* now.

1890

* now.

1891

*/

1891

*/

1892

if (p->on_rq && !rq->rt.rt_nr_running)

1892

if (!p->on_rq || rq->rt.rt_nr_running)

1893

pull_rt_task(rq);

1893

return;

1894

1895

if (pull_rt_task(rq))

1896

resched_task(rq->curr);

1894

}

1897

}

1895

1898

1896

void init_sched_rt_class(void)

1899

void init_sched_rt_class(void)

1897

{

1900

{

1898

unsigned int i;

1901

unsigned int i;

1899

1902

1900

for_each_possible_cpu(i) {

1903

for_each_possible_cpu(i) {

1901

zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),

1904

zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),

1902

GFP_KERNEL, cpu_to_node(i));

1905

GFP_KERNEL, cpu_to_node(i));

1903

}

1906

}

1904

}

1907

}

1905

#endif /* CONFIG_SMP */

1908

#endif /* CONFIG_SMP */

1906

1909

1907

/*

1910

/*

1908

* When switching a task to RT, we may overload the runqueue

1911

* When switching a task to RT, we may overload the runqueue

1909

* with RT tasks. In this case we try to push them off to

1912

* with RT tasks. In this case we try to push them off to

1910

* other runqueues.

1913

* other runqueues.

1911

*/

1914

*/

1912

static void switched_to_rt(struct rq *rq, struct task_struct *p)

1915

static void switched_to_rt(struct rq *rq, struct task_struct *p)

1913

{

1916

{

1914

int check_resched = 1;

1917

int check_resched = 1;

1915

1918

1916

/*

1919

/*

1917

* If we are already running, then there's nothing

1920

* If we are already running, then there's nothing

1918

* that needs to be done. But if we are not running

1921

* that needs to be done. But if we are not running

1919

* we may need to preempt the current running task.

1922

* we may need to preempt the current running task.

1920

* If that current running task is also an RT task

1923

* If that current running task is also an RT task

1921

* then see if we can move to another run queue.

1924

* then see if we can move to another run queue.

1922

*/

1925

*/

1923

if (p->on_rq && rq->curr != p) {

1926

if (p->on_rq && rq->curr != p) {

1924

#ifdef CONFIG_SMP

1927

#ifdef CONFIG_SMP

1925

if (rq->rt.overloaded && push_rt_task(rq) &&

1928

if (rq->rt.overloaded && push_rt_task(rq) &&

1926

/* Don't resched if we changed runqueues */

1929

/* Don't resched if we changed runqueues */

1927

rq != task_rq(p))

1930

rq != task_rq(p))

1928

check_resched = 0;

1931

check_resched = 0;

1929

#endif /* CONFIG_SMP */

1932

#endif /* CONFIG_SMP */

1930

if (check_resched && p->prio < rq->curr->prio)

1933

if (check_resched && p->prio < rq->curr->prio)

1931

resched_task(rq->curr);

1934

resched_task(rq->curr);

1932

}

1935

}

1933

}

1936

}

1934

1937

1935

/*

1938

/*

1936

* Priority of the task has changed. This may cause

1939

* Priority of the task has changed. This may cause

1937

* us to initiate a push or pull.

1940

* us to initiate a push or pull.

1938

*/

1941

*/

1939

static void

1942

static void

1940

prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)

1943

prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)

1941

{

1944

{

1942

if (!p->on_rq)

1945

if (!p->on_rq)

1943

return;

1946

return;

1944

1947

1945

if (rq->curr == p) {

1948

if (rq->curr == p) {

1946

#ifdef CONFIG_SMP

1949

#ifdef CONFIG_SMP

1947

/*

1950

/*

1948

* If our priority decreases while running, we

1951

* If our priority decreases while running, we

1949

* may need to pull tasks to this runqueue.

1952

* may need to pull tasks to this runqueue.

1950

*/

1953

*/

1951

if (oldprio < p->prio)

1954

if (oldprio < p->prio)

1952

pull_rt_task(rq);

1955

pull_rt_task(rq);

1953

/*

1956

/*

1954

* If there's a higher priority task waiting to run

1957

* If there's a higher priority task waiting to run

1955

* then reschedule. Note, the above pull_rt_task

1958

* then reschedule. Note, the above pull_rt_task

1956

* can release the rq lock and p could migrate.

1959

* can release the rq lock and p could migrate.

1957

* Only reschedule if p is still on the same runqueue.

1960

* Only reschedule if p is still on the same runqueue.

1958

*/

1961

*/

1959

if (p->prio > rq->rt.highest_prio.curr && rq->curr == p)

1962

if (p->prio > rq->rt.highest_prio.curr && rq->curr == p)

1960

resched_task(p);

1963

resched_task(p);

1961

#else

1964

#else

1962

/* For UP simply resched on drop of prio */

1965

/* For UP simply resched on drop of prio */

1963

if (oldprio < p->prio)

1966

if (oldprio < p->prio)

1964

resched_task(p);

1967

resched_task(p);

1965

#endif /* CONFIG_SMP */

1968

#endif /* CONFIG_SMP */

1966

} else {

1969

} else {

1967

/*

1970

/*

1968

* This task is not running, but if it is

1971

* This task is not running, but if it is

1969

* greater than the current running task

1972

* greater than the current running task

1970

* then reschedule.

1973

* then reschedule.

1971

*/

1974

*/

1972

if (p->prio < rq->curr->prio)

1975

if (p->prio < rq->curr->prio)

1973

resched_task(rq->curr);

1976

resched_task(rq->curr);

1974

}

1977

}

1975

}

1978

}

1976

1979

1977

static void watchdog(struct rq *rq, struct task_struct *p)

1980

static void watchdog(struct rq *rq, struct task_struct *p)

1978

{

1981

{

1979

unsigned long soft, hard;

1982

unsigned long soft, hard;

1980

1983

1981

/* max may change after cur was read, this will be fixed next tick */

1984

/* max may change after cur was read, this will be fixed next tick */

1982

soft = task_rlimit(p, RLIMIT_RTTIME);

1985

soft = task_rlimit(p, RLIMIT_RTTIME);

1983

hard = task_rlimit_max(p, RLIMIT_RTTIME);

1986

hard = task_rlimit_max(p, RLIMIT_RTTIME);

1984

1987

1985

if (soft != RLIM_INFINITY) {

1988

if (soft != RLIM_INFINITY) {

1986

unsigned long next;

1989

unsigned long next;

1987

1990

1988

p->rt.timeout++;

1991

p->rt.timeout++;

1989

next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);

1992

next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);

1990

if (p->rt.timeout > next)

1993

if (p->rt.timeout > next)

1991

p->cputime_expires.sched_exp = p->se.sum_exec_runtime;

1994

p->cputime_expires.sched_exp = p->se.sum_exec_runtime;

1992

}

1995

}

1993

}

1996

}

1994

1997

1995

static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)

1998

static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)

1996

{

1999

{

1997

struct sched_rt_entity *rt_se = &p->rt;

2000

struct sched_rt_entity *rt_se = &p->rt;

1998

2001

1999

update_curr_rt(rq);

2002

update_curr_rt(rq);

2000

2003

2001

watchdog(rq, p);

2004

watchdog(rq, p);

2002

2005

2003

/*

2006

/*

2004

* RR tasks need a special form of timeslice management.

2007

* RR tasks need a special form of timeslice management.

2005

* FIFO tasks have no timeslices.

2008

* FIFO tasks have no timeslices.

2006

*/

2009

*/

2007

if (p->policy != SCHED_RR)

2010

if (p->policy != SCHED_RR)

2008

return;

2011

return;

2009

2012

2010

if (--p->rt.time_slice)

2013

if (--p->rt.time_slice)

2011

return;

2014

return;

2012

2015

2013

p->rt.time_slice = RR_TIMESLICE;

2016

p->rt.time_slice = RR_TIMESLICE;

2014

2017

2015

/*

2018

/*

2016

* Requeue to the end of queue if we (and all of our ancestors) are the

2019

* Requeue to the end of queue if we (and all of our ancestors) are the

2017

* only element on the queue

2020

* only element on the queue

2018

*/

2021

*/

2019

for_each_sched_rt_entity(rt_se) {

2022

for_each_sched_rt_entity(rt_se) {

2020

if (rt_se->run_list.prev != rt_se->run_list.next) {

2023

if (rt_se->run_list.prev != rt_se->run_list.next) {

2021

requeue_task_rt(rq, p, 0);

2024

requeue_task_rt(rq, p, 0);

2022

set_tsk_need_resched(p);

2025

set_tsk_need_resched(p);

2023

return;

2026

return;

2024

}

2027

}

2025

}

2028

}

2026

}

2029

}

2027

2030

2028

static void set_curr_task_rt(struct rq *rq)

2031

static void set_curr_task_rt(struct rq *rq)

2029

{

2032

{

2030

struct task_struct *p = rq->curr;

2033

struct task_struct *p = rq->curr;

2031

2034

2032

p->se.exec_start = rq->clock_task;

2035

p->se.exec_start = rq->clock_task;

2033

2036

2034

/* The running task is never eligible for pushing */

2037

/* The running task is never eligible for pushing */

2035

dequeue_pushable_task(rq, p);

2038

dequeue_pushable_task(rq, p);

2036

}

2039

}

2037

2040

2038

static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)

2041

static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)

2039

{

2042

{

2040

/*

2043

/*

2041

* Time slice is 0 for SCHED_FIFO tasks

2044

* Time slice is 0 for SCHED_FIFO tasks

2042

*/

2045

*/

2043

if (task->policy == SCHED_RR)

2046

if (task->policy == SCHED_RR)

2044

return RR_TIMESLICE;

2047

return RR_TIMESLICE;

2045

else

2048

else

2046

return 0;

2049

return 0;

2047

}

2050

}

2048

2051

2049

const struct sched_class rt_sched_class = {

2052

const struct sched_class rt_sched_class = {

2050

.next = &fair_sched_class,

2053

.next = &fair_sched_class,

2051

.enqueue_task = enqueue_task_rt,

2054

.enqueue_task = enqueue_task_rt,

2052

.dequeue_task = dequeue_task_rt,

2055

.dequeue_task = dequeue_task_rt,

2053

.yield_task = yield_task_rt,

2056

.yield_task = yield_task_rt,

2054

2057

2055

.check_preempt_curr = check_preempt_curr_rt,

2058

.check_preempt_curr = check_preempt_curr_rt,

2056

2059

2057

.pick_next_task = pick_next_task_rt,

2060

.pick_next_task = pick_next_task_rt,

2058

.put_prev_task = put_prev_task_rt,

2061

.put_prev_task = put_prev_task_rt,

2059

2062

2060

#ifdef CONFIG_SMP

2063

#ifdef CONFIG_SMP

2061

.select_task_rq = select_task_rq_rt,

2064

.select_task_rq = select_task_rq_rt,

2062

2065

2063

.set_cpus_allowed = set_cpus_allowed_rt,

2066

.set_cpus_allowed = set_cpus_allowed_rt,

2064

.rq_online = rq_online_rt,

2067

.rq_online = rq_online_rt,

2065

.rq_offline = rq_offline_rt,

2068

.rq_offline = rq_offline_rt,

2066

.pre_schedule = pre_schedule_rt,

2069

.pre_schedule = pre_schedule_rt,

2067

.post_schedule = post_schedule_rt,

2070

.post_schedule = post_schedule_rt,

2068

.task_woken = task_woken_rt,

2071

.task_woken = task_woken_rt,

2069

.switched_from = switched_from_rt,

2072

.switched_from = switched_from_rt,

2070

#endif

2073

#endif

2071

2074

2072

.set_curr_task = set_curr_task_rt,

2075

.set_curr_task = set_curr_task_rt,

2073

.task_tick = task_tick_rt,

2076

.task_tick = task_tick_rt,

2074

2077

2075

.get_rr_interval = get_rr_interval_rt,

2078

.get_rr_interval = get_rr_interval_rt,

2076

2079

2077

.prio_changed = prio_changed_rt,

2080

.prio_changed = prio_changed_rt,

2078

.switched_to = switched_to_rt,

2081

.switched_to = switched_to_rt,

2079

};

2082

};

2080

2083

2081

#ifdef CONFIG_SCHED_DEBUG

2084

#ifdef CONFIG_SCHED_DEBUG

2082

extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);

2085

extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);

2083

2086

2084

void print_rt_stats(struct seq_file *m, int cpu)

2087

void print_rt_stats(struct seq_file *m, int cpu)

2085

{

2088

{

2086

rt_rq_iter_t iter;

2089

rt_rq_iter_t iter;

2087

struct rt_rq *rt_rq;

2090

struct rt_rq *rt_rq;

2088

2091

2089

rcu_read_lock();

2092

rcu_read_lock();

2090

for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))

2093

for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))

2091

print_rt_rq(m, cpu, rt_rq);

2094

print_rt_rq(m, cpu, rt_rq);

2092

rcu_read_unlock();

2095

rcu_read_unlock();

2093

}

2096

}

2094

#endif /* CONFIG_SCHED_DEBUG */

2097

#endif /* CONFIG_SCHED_DEBUG */

2095

2098

GITLAB

sched/rt: Add reschedule check to switched_from_rt()

 /*
  * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
  * policies)
  */
 #include "sched.h"
 #include <linux/slab.h>
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
 struct rt_bandwidth def_rt_bandwidth;
 static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer)
 {
 	struct rt_bandwidth *rt_b =
 		container_of(timer, struct rt_bandwidth, rt_period_timer);
 	ktime_t now;
 	int overrun;
 	int idle = 0;
 	for (;;) {
 		now = hrtimer_cb_get_time(timer);
 		overrun = hrtimer_forward(timer, now, rt_b->rt_period);
 		if (!overrun)
 			break;
 		idle = do_sched_rt_period_timer(rt_b, overrun);
 	}
 	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
 }
 void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
 {
 	rt_b->rt_period = ns_to_ktime(period);
 	rt_b->rt_runtime = runtime;
 	raw_spin_lock_init(&rt_b->rt_runtime_lock);
 	hrtimer_init(&rt_b->rt_period_timer,
 			CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	rt_b->rt_period_timer.function = sched_rt_period_timer;
 }
 static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
 	if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
 		return;
 	if (hrtimer_active(&rt_b->rt_period_timer))
 		return;
 	raw_spin_lock(&rt_b->rt_runtime_lock);
 	start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period);
 	raw_spin_unlock(&rt_b->rt_runtime_lock);
 }
 void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
 {
 	struct rt_prio_array *array;
 	int i;
 	array = &rt_rq->active;
 	for (i = 0; i < MAX_RT_PRIO; i++) {
 		INIT_LIST_HEAD(array->queue + i);
 		__clear_bit(i, array->bitmap);
 	}
 	/* delimiter for bitsearch: */
 	__set_bit(MAX_RT_PRIO, array->bitmap);
 #if defined CONFIG_SMP
 	rt_rq->highest_prio.curr = MAX_RT_PRIO;
 	rt_rq->highest_prio.next = MAX_RT_PRIO;
 	rt_rq->rt_nr_migratory = 0;
 	rt_rq->overloaded = 0;
 	plist_head_init(&rt_rq->pushable_tasks);
 #endif
 	rt_rq->rt_time = 0;
 	rt_rq->rt_throttled = 0;
 	rt_rq->rt_runtime = 0;
 	raw_spin_lock_init(&rt_rq->rt_runtime_lock);
 }
 #ifdef CONFIG_RT_GROUP_SCHED
 static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
 {
 	hrtimer_cancel(&rt_b->rt_period_timer);
 }
 #define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
 static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
 {
 #ifdef CONFIG_SCHED_DEBUG
 	WARN_ON_ONCE(!rt_entity_is_task(rt_se));
 #endif
 	return container_of(rt_se, struct task_struct, rt);
 }
 static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
 {
 	return rt_rq->rq;
 }
 static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 {
 	return rt_se->rt_rq;
 }
 void free_rt_sched_group(struct task_group *tg)
 {
 	int i;
 	if (tg->rt_se)
 		destroy_rt_bandwidth(&tg->rt_bandwidth);
 	for_each_possible_cpu(i) {
 		if (tg->rt_rq)
 			kfree(tg->rt_rq[i]);
 		if (tg->rt_se)
 			kfree(tg->rt_se[i]);
 	}
 	kfree(tg->rt_rq);
 	kfree(tg->rt_se);
 }
 void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
 		struct sched_rt_entity *rt_se, int cpu,
 		struct sched_rt_entity *parent)
 {
 	struct rq *rq = cpu_rq(cpu);
 	rt_rq->highest_prio.curr = MAX_RT_PRIO;
 	rt_rq->rt_nr_boosted = 0;
 	rt_rq->rq = rq;
 	rt_rq->tg = tg;
 	tg->rt_rq[cpu] = rt_rq;
 	tg->rt_se[cpu] = rt_se;
 	if (!rt_se)
 		return;
 	if (!parent)
 		rt_se->rt_rq = &rq->rt;
 	else
 		rt_se->rt_rq = parent->my_q;
 	rt_se->my_q = rt_rq;
 	rt_se->parent = parent;
 	INIT_LIST_HEAD(&rt_se->run_list);
 }
 int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
 {
 	struct rt_rq *rt_rq;
 	struct sched_rt_entity *rt_se;
 	int i;
 	tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->rt_rq)
 		goto err;
 	tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL);
 	if (!tg->rt_se)
 		goto err;
 	init_rt_bandwidth(&tg->rt_bandwidth,
 			ktime_to_ns(def_rt_bandwidth.rt_period), 0);
 	for_each_possible_cpu(i) {
 		rt_rq = kzalloc_node(sizeof(struct rt_rq),
 				     GFP_KERNEL, cpu_to_node(i));
 		if (!rt_rq)
 			goto err;
 		rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
 				     GFP_KERNEL, cpu_to_node(i));
 		if (!rt_se)
 			goto err_free_rq;
 		init_rt_rq(rt_rq, cpu_rq(i));
 		rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime;
 		init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]);
 	}
 	return 1;
 err_free_rq:
 	kfree(rt_rq);
 err:
 	return 0;
 }
 #else /* CONFIG_RT_GROUP_SCHED */
 #define rt_entity_is_task(rt_se) (1)
 static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
 {
 	return container_of(rt_se, struct task_struct, rt);
 }
 static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
 {
 	return container_of(rt_rq, struct rq, rt);
 }
 static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
 {
 	struct task_struct *p = rt_task_of(rt_se);
 	struct rq *rq = task_rq(p);
 	return &rq->rt;
 }
 void free_rt_sched_group(struct task_group *tg) { }
 int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
 {
 	return 1;
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 #ifdef CONFIG_SMP
 static inline int rt_overloaded(struct rq *rq)
 {
 	return atomic_read(&rq->rd->rto_count);
 }
 static inline void rt_set_overload(struct rq *rq)
 {
 	if (!rq->online)
 		return;
 	cpumask_set_cpu(rq->cpu, rq->rd->rto_mask);
 	/*
 	 * Make sure the mask is visible before we set
 	 * the overload count. That is checked to determine
 	 * if we should look at the mask. It would be a shame
 	 * if we looked at the mask, but the mask was not
 	 * updated yet.
 	 */
 	wmb();
 	atomic_inc(&rq->rd->rto_count);
 }
 static inline void rt_clear_overload(struct rq *rq)
 {
 	if (!rq->online)
 		return;
 	/* the order here really doesn't matter */
 	atomic_dec(&rq->rd->rto_count);
 	cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask);
 }
 static void update_rt_migration(struct rt_rq *rt_rq)
 {
 	if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) {
 		if (!rt_rq->overloaded) {
 			rt_set_overload(rq_of_rt_rq(rt_rq));
 			rt_rq->overloaded = 1;
 		}
 	} else if (rt_rq->overloaded) {
 		rt_clear_overload(rq_of_rt_rq(rt_rq));
 		rt_rq->overloaded = 0;
 	}
 }
 static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	struct task_struct *p;
 	if (!rt_entity_is_task(rt_se))
 		return;
 	p = rt_task_of(rt_se);
 	rt_rq = &rq_of_rt_rq(rt_rq)->rt;
 	rt_rq->rt_nr_total++;
 	if (p->nr_cpus_allowed > 1)
 		rt_rq->rt_nr_migratory++;
 	update_rt_migration(rt_rq);
 }
 static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	struct task_struct *p;
 	if (!rt_entity_is_task(rt_se))
 		return;
 	p = rt_task_of(rt_se);
 	rt_rq = &rq_of_rt_rq(rt_rq)->rt;
 	rt_rq->rt_nr_total--;
 	if (p->nr_cpus_allowed > 1)
 		rt_rq->rt_nr_migratory--;
 	update_rt_migration(rt_rq);
 }
 static inline int has_pushable_tasks(struct rq *rq)
 {
 	return !plist_head_empty(&rq->rt.pushable_tasks);
 }
 static void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
 {
 	plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
 	plist_node_init(&p->pushable_tasks, p->prio);
 	plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks);
 	/* Update the highest prio pushable task */
 	if (p->prio < rq->rt.highest_prio.next)
 		rq->rt.highest_prio.next = p->prio;
 }
 static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
 {
 	plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
 	/* Update the new highest prio pushable task */
 	if (has_pushable_tasks(rq)) {
 		p = plist_first_entry(&rq->rt.pushable_tasks,
 				      struct task_struct, pushable_tasks);
 		rq->rt.highest_prio.next = p->prio;
 	} else
 		rq->rt.highest_prio.next = MAX_RT_PRIO;
 }
 #else
 static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
 {
 }
 static inline void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
 {
 }
 static inline
 void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 }
 static inline
 void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 }
 #endif /* CONFIG_SMP */
 static inline int on_rt_rq(struct sched_rt_entity *rt_se)
 {
 	return !list_empty(&rt_se->run_list);
 }
 #ifdef CONFIG_RT_GROUP_SCHED
 static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
 {
 	if (!rt_rq->tg)
 		return RUNTIME_INF;
 	return rt_rq->rt_runtime;
 }
 static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 {
 	return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
 }
 typedef struct task_group *rt_rq_iter_t;
 static inline struct task_group *next_task_group(struct task_group *tg)
 {
 	do {
 		tg = list_entry_rcu(tg->list.next,
 			typeof(struct task_group), list);
 	} while (&tg->list != &task_groups && task_group_is_autogroup(tg));
 	if (&tg->list == &task_groups)
 		tg = NULL;
 	return tg;
 }
 #define for_each_rt_rq(rt_rq, iter, rq)					\
 	for (iter = container_of(&task_groups, typeof(*iter), list);	\
 		(iter = next_task_group(iter)) &&			\
 		(rt_rq = iter->rt_rq[cpu_of(rq)]);)
 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
 	list_add_rcu(&rt_rq->leaf_rt_rq_list,
 			&rq_of_rt_rq(rt_rq)->leaf_rt_rq_list);
 }
 static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)
 {
 	list_del_rcu(&rt_rq->leaf_rt_rq_list);
 }
 #define for_each_leaf_rt_rq(rt_rq, rq) \
 	list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list)
 #define for_each_sched_rt_entity(rt_se) \
 	for (; rt_se; rt_se = rt_se->parent)
 static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
 {
 	return rt_se->my_q;
 }
 static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);
 static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
 static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
 	struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr;
 	struct sched_rt_entity *rt_se;
 	int cpu = cpu_of(rq_of_rt_rq(rt_rq));
 	rt_se = rt_rq->tg->rt_se[cpu];
 	if (rt_rq->rt_nr_running) {
 		if (rt_se && !on_rt_rq(rt_se))
 			enqueue_rt_entity(rt_se, false);
 		if (rt_rq->highest_prio.curr < curr->prio)
 			resched_task(curr);
 	}
 }
 static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
 {
 	struct sched_rt_entity *rt_se;
 	int cpu = cpu_of(rq_of_rt_rq(rt_rq));
 	rt_se = rt_rq->tg->rt_se[cpu];
 	if (rt_se && on_rt_rq(rt_se))
 		dequeue_rt_entity(rt_se);
 }
 static inline int rt_rq_throttled(struct rt_rq *rt_rq)
 {
 	return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted;
 }
 static int rt_se_boosted(struct sched_rt_entity *rt_se)
 {
 	struct rt_rq *rt_rq = group_rt_rq(rt_se);
 	struct task_struct *p;
 	if (rt_rq)
 		return !!rt_rq->rt_nr_boosted;
 	p = rt_task_of(rt_se);
 	return p->prio != p->normal_prio;
 }
 #ifdef CONFIG_SMP
 static inline const struct cpumask *sched_rt_period_mask(void)
 {
 	return cpu_rq(smp_processor_id())->rd->span;
 }
 #else
 static inline const struct cpumask *sched_rt_period_mask(void)
 {
 	return cpu_online_mask;
 }
 #endif
 static inline
 struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
 {
 	return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
 }
 static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
 {
 	return &rt_rq->tg->rt_bandwidth;
 }
 #else /* !CONFIG_RT_GROUP_SCHED */
 static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
 {
 	return rt_rq->rt_runtime;
 }
 static inline u64 sched_rt_period(struct rt_rq *rt_rq)
 {
 	return ktime_to_ns(def_rt_bandwidth.rt_period);
 }
 typedef struct rt_rq *rt_rq_iter_t;
 #define for_each_rt_rq(rt_rq, iter, rq) \
 	for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
 static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq)
 {
 }
 static inline void list_del_leaf_rt_rq(struct rt_rq *rt_rq)
 {
 }
 #define for_each_leaf_rt_rq(rt_rq, rq) \
 	for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL)
 #define for_each_sched_rt_entity(rt_se) \
 	for (; rt_se; rt_se = NULL)
 static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
 {
 	return NULL;
 }
 static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
 {
 	if (rt_rq->rt_nr_running)
 		resched_task(rq_of_rt_rq(rt_rq)->curr);
 }
 static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
 {
 }
 static inline int rt_rq_throttled(struct rt_rq *rt_rq)
 {
 	return rt_rq->rt_throttled;
 }
 static inline const struct cpumask *sched_rt_period_mask(void)
 {
 	return cpu_online_mask;
 }
 static inline
 struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
 {
 	return &cpu_rq(cpu)->rt;
 }
 static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
 {
 	return &def_rt_bandwidth;
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 #ifdef CONFIG_SMP
 /*
  * We ran out of runtime, see if we can borrow some from our neighbours.
  */
 static int do_balance_runtime(struct rt_rq *rt_rq)
 {
 	struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
 	struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
 	int i, weight, more = 0;
 	u64 rt_period;
 	weight = cpumask_weight(rd->span);
 	raw_spin_lock(&rt_b->rt_runtime_lock);
 	rt_period = ktime_to_ns(rt_b->rt_period);
 	for_each_cpu(i, rd->span) {
 		struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
 		s64 diff;
 		if (iter == rt_rq)
 			continue;
 		raw_spin_lock(&iter->rt_runtime_lock);
 		/*
 		 * Either all rqs have inf runtime and there's nothing to steal
 		 * or __disable_runtime() below sets a specific rq to inf to
 		 * indicate its been disabled and disalow stealing.
 		 */
 		if (iter->rt_runtime == RUNTIME_INF)
 			goto next;
 		/*
 		 * From runqueues with spare time, take 1/n part of their
 		 * spare time, but no more than our period.
 		 */
 		diff = iter->rt_runtime - iter->rt_time;
 		if (diff > 0) {
 			diff = div_u64((u64)diff, weight);
 			if (rt_rq->rt_runtime + diff > rt_period)
 				diff = rt_period - rt_rq->rt_runtime;
 			iter->rt_runtime -= diff;
 			rt_rq->rt_runtime += diff;
 			more = 1;
 			if (rt_rq->rt_runtime == rt_period) {
 				raw_spin_unlock(&iter->rt_runtime_lock);
 				break;
 			}
 		}
 next:
 		raw_spin_unlock(&iter->rt_runtime_lock);
 	}
 	raw_spin_unlock(&rt_b->rt_runtime_lock);
 	return more;
 }
 /*
  * Ensure this RQ takes back all the runtime it lend to its neighbours.
  */
 static void __disable_runtime(struct rq *rq)
 {
 	struct root_domain *rd = rq->rd;
 	rt_rq_iter_t iter;
 	struct rt_rq *rt_rq;
 	if (unlikely(!scheduler_running))
 		return;
 	for_each_rt_rq(rt_rq, iter, rq) {
 		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
 		s64 want;
 		int i;
 		raw_spin_lock(&rt_b->rt_runtime_lock);
 		raw_spin_lock(&rt_rq->rt_runtime_lock);
 		/*
 		 * Either we're all inf and nobody needs to borrow, or we're
 		 * already disabled and thus have nothing to do, or we have
 		 * exactly the right amount of runtime to take out.
 		 */
 		if (rt_rq->rt_runtime == RUNTIME_INF ||
 				rt_rq->rt_runtime == rt_b->rt_runtime)
 			goto balanced;
 		raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		/*
 		 * Calculate the difference between what we started out with
 		 * and what we current have, that's the amount of runtime
 		 * we lend and now have to reclaim.
 		 */
 		want = rt_b->rt_runtime - rt_rq->rt_runtime;
 		/*
 		 * Greedy reclaim, take back as much as we can.
 		 */
 		for_each_cpu(i, rd->span) {
 			struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
 			s64 diff;
 			/*
 			 * Can't reclaim from ourselves or disabled runqueues.
 			 */
 			if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF)
 				continue;
 			raw_spin_lock(&iter->rt_runtime_lock);
 			if (want > 0) {
 				diff = min_t(s64, iter->rt_runtime, want);
 				iter->rt_runtime -= diff;
 				want -= diff;
 			} else {
 				iter->rt_runtime -= want;
 				want -= want;
 			}
 			raw_spin_unlock(&iter->rt_runtime_lock);
 			if (!want)
 				break;
 		}
 		raw_spin_lock(&rt_rq->rt_runtime_lock);
 		/*
 		 * We cannot be left wanting - that would mean some runtime
 		 * leaked out of the system.
 		 */
 		BUG_ON(want);
 balanced:
 		/*
 		 * Disable all the borrow logic by pretending we have inf
 		 * runtime - in which case borrowing doesn't make sense.
 		 */
 		rt_rq->rt_runtime = RUNTIME_INF;
 		rt_rq->rt_throttled = 0;
 		raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		raw_spin_unlock(&rt_b->rt_runtime_lock);
 	}
 }
 static void disable_runtime(struct rq *rq)
 {
 	unsigned long flags;
 	raw_spin_lock_irqsave(&rq->lock, flags);
 	__disable_runtime(rq);
 	raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 static void __enable_runtime(struct rq *rq)
 {
 	rt_rq_iter_t iter;
 	struct rt_rq *rt_rq;
 	if (unlikely(!scheduler_running))
 		return;
 	/*
 	 * Reset each runqueue's bandwidth settings
 	 */
 	for_each_rt_rq(rt_rq, iter, rq) {
 		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
 		raw_spin_lock(&rt_b->rt_runtime_lock);
 		raw_spin_lock(&rt_rq->rt_runtime_lock);
 		rt_rq->rt_runtime = rt_b->rt_runtime;
 		rt_rq->rt_time = 0;
 		rt_rq->rt_throttled = 0;
 		raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		raw_spin_unlock(&rt_b->rt_runtime_lock);
 	}
 }
 static void enable_runtime(struct rq *rq)
 {
 	unsigned long flags;
 	raw_spin_lock_irqsave(&rq->lock, flags);
 	__enable_runtime(rq);
 	raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
 	int cpu = (int)(long)hcpu;
 	switch (action) {
 	case CPU_DOWN_PREPARE:
 	case CPU_DOWN_PREPARE_FROZEN:
 		disable_runtime(cpu_rq(cpu));
 		return NOTIFY_OK;
 	case CPU_DOWN_FAILED:
 	case CPU_DOWN_FAILED_FROZEN:
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
 		enable_runtime(cpu_rq(cpu));
 		return NOTIFY_OK;
 	default:
 		return NOTIFY_DONE;
 	}
 }
 static int balance_runtime(struct rt_rq *rt_rq)
 {
 	int more = 0;
 	if (!sched_feat(RT_RUNTIME_SHARE))
 		return more;
 	if (rt_rq->rt_time > rt_rq->rt_runtime) {
 		raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		more = do_balance_runtime(rt_rq);
 		raw_spin_lock(&rt_rq->rt_runtime_lock);
 	}
 	return more;
 }
 #else /* !CONFIG_SMP */
 static inline int balance_runtime(struct rt_rq *rt_rq)
 {
 	return 0;
 }
 #endif /* CONFIG_SMP */
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
 {
 	int i, idle = 1, throttled = 0;
 	const struct cpumask *span;
 	span = sched_rt_period_mask();
 #ifdef CONFIG_RT_GROUP_SCHED
 	/*
 	 * FIXME: isolated CPUs should really leave the root task group,
 	 * whether they are isolcpus or were isolated via cpusets, lest
 	 * the timer run on a CPU which does not service all runqueues,
 	 * potentially leaving other CPUs indefinitely throttled.  If
 	 * isolation is really required, the user will turn the throttle
 	 * off to kill the perturbations it causes anyway.  Meanwhile,
 	 * this maintains functionality for boot and/or troubleshooting.
 	 */
 	if (rt_b == &root_task_group.rt_bandwidth)
 		span = cpu_online_mask;
 #endif
 	for_each_cpu(i, span) {
 		int enqueue = 0;
 		struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
 		struct rq *rq = rq_of_rt_rq(rt_rq);
 		raw_spin_lock(&rq->lock);
 		if (rt_rq->rt_time) {
 			u64 runtime;
 			raw_spin_lock(&rt_rq->rt_runtime_lock);
 			if (rt_rq->rt_throttled)
 				balance_runtime(rt_rq);
 			runtime = rt_rq->rt_runtime;
 			rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
 			if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
 				rt_rq->rt_throttled = 0;
 				enqueue = 1;
 				/*
 				 * Force a clock update if the CPU was idle,
 				 * lest wakeup -> unthrottle time accumulate.
 				 */
 				if (rt_rq->rt_nr_running && rq->curr == rq->idle)
 					rq->skip_clock_update = -1;
 			}
 			if (rt_rq->rt_time || rt_rq->rt_nr_running)
 				idle = 0;
 			raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		} else if (rt_rq->rt_nr_running) {
 			idle = 0;
 			if (!rt_rq_throttled(rt_rq))
 				enqueue = 1;
 		}
 		if (rt_rq->rt_throttled)
 			throttled = 1;
 		if (enqueue)
 			sched_rt_rq_enqueue(rt_rq);
 		raw_spin_unlock(&rq->lock);
 	}
 	if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))
 		return 1;
 	return idle;
 }
 static inline int rt_se_prio(struct sched_rt_entity *rt_se)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
 	struct rt_rq *rt_rq = group_rt_rq(rt_se);
 	if (rt_rq)
 		return rt_rq->highest_prio.curr;
 #endif
 	return rt_task_of(rt_se)->prio;
 }
 static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
 {
 	u64 runtime = sched_rt_runtime(rt_rq);
 	if (rt_rq->rt_throttled)
 		return rt_rq_throttled(rt_rq);
 	if (runtime >= sched_rt_period(rt_rq))
 		return 0;
 	balance_runtime(rt_rq);
 	runtime = sched_rt_runtime(rt_rq);
 	if (runtime == RUNTIME_INF)
 		return 0;
 	if (rt_rq->rt_time > runtime) {
 		struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
 		/*
 		 * Don't actually throttle groups that have no runtime assigned
 		 * but accrue some time due to boosting.
 		 */
 		if (likely(rt_b->rt_runtime)) {
 			static bool once = false;
 			rt_rq->rt_throttled = 1;
 			if (!once) {
 				once = true;
 				printk_sched("sched: RT throttling activated\n");
 			}
 		} else {
 			/*
 			 * In case we did anyway, make it go away,
 			 * replenishment is a joke, since it will replenish us
 			 * with exactly 0 ns.
 			 */
 			rt_rq->rt_time = 0;
 		}
 		if (rt_rq_throttled(rt_rq)) {
 			sched_rt_rq_dequeue(rt_rq);
 			return 1;
 		}
 	}
 	return 0;
 }
 /*
  * Update the current task's runtime statistics. Skip current tasks that
  * are not in our scheduling class.
  */
 static void update_curr_rt(struct rq *rq)
 {
 	struct task_struct *curr = rq->curr;
 	struct sched_rt_entity *rt_se = &curr->rt;
 	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 	u64 delta_exec;
 	if (curr->sched_class != &rt_sched_class)
 		return;
 	delta_exec = rq->clock_task - curr->se.exec_start;
 	if (unlikely((s64)delta_exec < 0))
 		delta_exec = 0;
 	schedstat_set(curr->se.statistics.exec_max,
 		      max(curr->se.statistics.exec_max, delta_exec));
 	curr->se.sum_exec_runtime += delta_exec;
 	account_group_exec_runtime(curr, delta_exec);
 	curr->se.exec_start = rq->clock_task;
 	cpuacct_charge(curr, delta_exec);
 	sched_rt_avg_update(rq, delta_exec);
 	if (!rt_bandwidth_enabled())
 		return;
 	for_each_sched_rt_entity(rt_se) {
 		rt_rq = rt_rq_of_se(rt_se);
 		if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
 			raw_spin_lock(&rt_rq->rt_runtime_lock);
 			rt_rq->rt_time += delta_exec;
 			if (sched_rt_runtime_exceeded(rt_rq))
 				resched_task(curr);
 			raw_spin_unlock(&rt_rq->rt_runtime_lock);
 		}
 	}
 }
 #if defined CONFIG_SMP
 static void
 inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
 {
 	struct rq *rq = rq_of_rt_rq(rt_rq);
 	if (rq->online && prio < prev_prio)
 		cpupri_set(&rq->rd->cpupri, rq->cpu, prio);
 }
 static void
 dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio)
 {
 	struct rq *rq = rq_of_rt_rq(rt_rq);
 	if (rq->online && rt_rq->highest_prio.curr != prev_prio)
 		cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr);
 }
 #else /* CONFIG_SMP */
 static inline
 void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
 static inline
 void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {}
 #endif /* CONFIG_SMP */
 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
 static void
 inc_rt_prio(struct rt_rq *rt_rq, int prio)
 {
 	int prev_prio = rt_rq->highest_prio.curr;
 	if (prio < prev_prio)
 		rt_rq->highest_prio.curr = prio;
 	inc_rt_prio_smp(rt_rq, prio, prev_prio);
 }
 static void
 dec_rt_prio(struct rt_rq *rt_rq, int prio)
 {
 	int prev_prio = rt_rq->highest_prio.curr;
 	if (rt_rq->rt_nr_running) {
 		WARN_ON(prio < prev_prio);
 		/*
 		 * This may have been our highest task, and therefore
 		 * we may have some recomputation to do
 		 */
 		if (prio == prev_prio) {
 			struct rt_prio_array *array = &rt_rq->active;
 			rt_rq->highest_prio.curr =
 				sched_find_first_bit(array->bitmap);
 		}
 	} else
 		rt_rq->highest_prio.curr = MAX_RT_PRIO;
 	dec_rt_prio_smp(rt_rq, prio, prev_prio);
 }
 #else
 static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {}
 static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {}
 #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */
 #ifdef CONFIG_RT_GROUP_SCHED
 static void
 inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	if (rt_se_boosted(rt_se))
 		rt_rq->rt_nr_boosted++;
 	if (rt_rq->tg)
 		start_rt_bandwidth(&rt_rq->tg->rt_bandwidth);
 }
 static void
 dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	if (rt_se_boosted(rt_se))
 		rt_rq->rt_nr_boosted--;
 	WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted);
 }
 #else /* CONFIG_RT_GROUP_SCHED */
 static void
 inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	start_rt_bandwidth(&def_rt_bandwidth);
 }
 static inline
 void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {}
 #endif /* CONFIG_RT_GROUP_SCHED */
 static inline
 void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	int prio = rt_se_prio(rt_se);
 	WARN_ON(!rt_prio(prio));
 	rt_rq->rt_nr_running++;
 	inc_rt_prio(rt_rq, prio);
 	inc_rt_migration(rt_se, rt_rq);
 	inc_rt_group(rt_se, rt_rq);
 }
 static inline
 void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
 {
 	WARN_ON(!rt_prio(rt_se_prio(rt_se)));
 	WARN_ON(!rt_rq->rt_nr_running);
 	rt_rq->rt_nr_running--;
 	dec_rt_prio(rt_rq, rt_se_prio(rt_se));
 	dec_rt_migration(rt_se, rt_rq);
 	dec_rt_group(rt_se, rt_rq);
 }
 static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
 {
 	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 	struct rt_prio_array *array = &rt_rq->active;
 	struct rt_rq *group_rq = group_rt_rq(rt_se);
 	struct list_head *queue = array->queue + rt_se_prio(rt_se);
 	/*
 	 * Don't enqueue the group if its throttled, or when empty.
 	 * The latter is a consequence of the former when a child group
 	 * get throttled and the current group doesn't have any other
 	 * active members.
 	 */
 	if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
 		return;
 	if (!rt_rq->rt_nr_running)
 		list_add_leaf_rt_rq(rt_rq);
 	if (head)
 		list_add(&rt_se->run_list, queue);
 	else
 		list_add_tail(&rt_se->run_list, queue);
 	__set_bit(rt_se_prio(rt_se), array->bitmap);
 	inc_rt_tasks(rt_se, rt_rq);
 }
 static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
 {
 	struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 	struct rt_prio_array *array = &rt_rq->active;
 	list_del_init(&rt_se->run_list);
 	if (list_empty(array->queue + rt_se_prio(rt_se)))
 		__clear_bit(rt_se_prio(rt_se), array->bitmap);
 	dec_rt_tasks(rt_se, rt_rq);
 	if (!rt_rq->rt_nr_running)
 		list_del_leaf_rt_rq(rt_rq);
 }
 /*
  * Because the prio of an upper entry depends on the lower
  * entries, we must remove entries top - down.
  */
 static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
 {
 	struct sched_rt_entity *back = NULL;
 	for_each_sched_rt_entity(rt_se) {
 		rt_se->back = back;
 		back = rt_se;
 	}
 	for (rt_se = back; rt_se; rt_se = rt_se->back) {
 		if (on_rt_rq(rt_se))
 			__dequeue_rt_entity(rt_se);
 	}
 }
 static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
 {
 	dequeue_rt_stack(rt_se);
 	for_each_sched_rt_entity(rt_se)
 		__enqueue_rt_entity(rt_se, head);
 }
 static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
 {
 	dequeue_rt_stack(rt_se);
 	for_each_sched_rt_entity(rt_se) {
 		struct rt_rq *rt_rq = group_rt_rq(rt_se);
 		if (rt_rq && rt_rq->rt_nr_running)
 			__enqueue_rt_entity(rt_se, false);
 	}
 }
 /*
  * Adding/removing a task to/from a priority array:
  */
 static void
 enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 {
 	struct sched_rt_entity *rt_se = &p->rt;
 	if (flags & ENQUEUE_WAKEUP)
 		rt_se->timeout = 0;
 	enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
 	if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_task(rq, p);
 	inc_nr_running(rq);
 }
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
 {
 	struct sched_rt_entity *rt_se = &p->rt;
 	update_curr_rt(rq);
 	dequeue_rt_entity(rt_se);
 	dequeue_pushable_task(rq, p);
 	dec_nr_running(rq);
 }
 /*
  * Put task to the head or the end of the run list without the overhead of
  * dequeue followed by enqueue.
  */
 static void
 requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
 {
 	if (on_rt_rq(rt_se)) {
 		struct rt_prio_array *array = &rt_rq->active;
 		struct list_head *queue = array->queue + rt_se_prio(rt_se);
 		if (head)
 			list_move(&rt_se->run_list, queue);
 		else
 			list_move_tail(&rt_se->run_list, queue);
 	}
 }
 static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
 {
 	struct sched_rt_entity *rt_se = &p->rt;
 	struct rt_rq *rt_rq;
 	for_each_sched_rt_entity(rt_se) {
 		rt_rq = rt_rq_of_se(rt_se);
 		requeue_rt_entity(rt_rq, rt_se, head);
 	}
 }
 static void yield_task_rt(struct rq *rq)
 {
 	requeue_task_rt(rq, rq->curr, 0);
 }
 #ifdef CONFIG_SMP
 static int find_lowest_rq(struct task_struct *task);
 static int
 select_task_rq_rt(struct task_struct *p, int sd_flag, int flags)
 {
 	struct task_struct *curr;
 	struct rq *rq;
 	int cpu;
 	cpu = task_cpu(p);
 	if (p->nr_cpus_allowed == 1)
 		goto out;
 	/* For anything but wake ups, just return the task_cpu */
 	if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
 		goto out;
 	rq = cpu_rq(cpu);
 	rcu_read_lock();
 	curr = ACCESS_ONCE(rq->curr); /* unlocked access */
 	/*
 	 * If the current task on @p's runqueue is an RT task, then
 	 * try to see if we can wake this RT task up on another
 	 * runqueue. Otherwise simply start this RT task
 	 * on its current runqueue.
 	 *
 	 * We want to avoid overloading runqueues. If the woken
 	 * task is a higher priority, then it will stay on this CPU
 	 * and the lower prio task should be moved to another CPU.
 	 * Even though this will probably make the lower prio task
 	 * lose its cache, we do not want to bounce a higher task
 	 * around just because it gave up its CPU, perhaps for a
 	 * lock?
 	 *
 	 * For equal prio tasks, we just let the scheduler sort it out.
 	 *
 	 * Otherwise, just let it ride on the affined RQ and the
 	 * post-schedule router will push the preempted task away
 	 *
 	 * This test is optimistic, if we get it wrong the load-balancer
 	 * will have to sort it out.
 	 */
 	if (curr && unlikely(rt_task(curr)) &&
 	    (curr->nr_cpus_allowed < 2 ||
 	     curr->prio <= p->prio) &&
 	    (p->nr_cpus_allowed > 1)) {
 		int target = find_lowest_rq(p);
 		if (target != -1)
 			cpu = target;
 	}
 	rcu_read_unlock();
 out:
 	return cpu;
 }
 static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 {
 	if (rq->curr->nr_cpus_allowed == 1)
 		return;
 	if (p->nr_cpus_allowed != 1
 	    && cpupri_find(&rq->rd->cpupri, p, NULL))
 		return;
 	if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
 		return;
 	/*
 	 * There appears to be other cpus that can accept
 	 * current and none to run 'p', so lets reschedule
 	 * to try and push current away:
 	 */
 	requeue_task_rt(rq, p, 1);
 	resched_task(rq->curr);
 }
 #endif /* CONFIG_SMP */
 /*
  * Preempt the current task with a newly woken task if needed:
  */
 static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags)
 {
 	if (p->prio < rq->curr->prio) {
 		resched_task(rq->curr);
 		return;
 	}
 #ifdef CONFIG_SMP
 	/*
 	 * If:
 	 *
 	 * - the newly woken task is of equal priority to the current task
 	 * - the newly woken task is non-migratable while current is migratable
 	 * - current will be preempted on the next reschedule
 	 *
 	 * we should check to see if current can readily move to a different
 	 * cpu.  If so, we will reschedule to allow the push logic to try
 	 * to move current somewhere else, making room for our non-migratable
 	 * task.
 	 */
 	if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))
 		check_preempt_equal_prio(rq, p);
 #endif
 }
 static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq,
 						   struct rt_rq *rt_rq)
 {
 	struct rt_prio_array *array = &rt_rq->active;
 	struct sched_rt_entity *next = NULL;
 	struct list_head *queue;
 	int idx;
 	idx = sched_find_first_bit(array->bitmap);
 	BUG_ON(idx >= MAX_RT_PRIO);
 	queue = array->queue + idx;
 	next = list_entry(queue->next, struct sched_rt_entity, run_list);
 	return next;
 }
 static struct task_struct *_pick_next_task_rt(struct rq *rq)
 {
 	struct sched_rt_entity *rt_se;
 	struct task_struct *p;
 	struct rt_rq *rt_rq;
 	rt_rq = &rq->rt;
 	if (!rt_rq->rt_nr_running)
 		return NULL;
 	if (rt_rq_throttled(rt_rq))
 		return NULL;
 	do {
 		rt_se = pick_next_rt_entity(rq, rt_rq);
 		BUG_ON(!rt_se);
 		rt_rq = group_rt_rq(rt_se);
 	} while (rt_rq);
 	p = rt_task_of(rt_se);
 	p->se.exec_start = rq->clock_task;
 	return p;
 }
 static struct task_struct *pick_next_task_rt(struct rq *rq)
 {
 	struct task_struct *p = _pick_next_task_rt(rq);
 	/* The running task is never eligible for pushing */
 	if (p)
 		dequeue_pushable_task(rq, p);
 #ifdef CONFIG_SMP
 	/*
 	 * We detect this state here so that we can avoid taking the RQ
 	 * lock again later if there is no need to push
 	 */
 	rq->post_schedule = has_pushable_tasks(rq);
 #endif
 	return p;
 }
 static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 {
 	update_curr_rt(rq);
 	/*
 	 * 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)
 		enqueue_pushable_task(rq, p);
 }
 #ifdef CONFIG_SMP
 /* Only try algorithms three times */
 #define RT_MAX_TRIES 3
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
 	    (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&
 	    (p->nr_cpus_allowed > 1))
 		return 1;
 	return 0;
 }
 /* Return the second highest RT task, NULL otherwise */
 static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu)
 {
 	struct task_struct *next = NULL;
 	struct sched_rt_entity *rt_se;
 	struct rt_prio_array *array;
 	struct rt_rq *rt_rq;
 	int idx;
 	for_each_leaf_rt_rq(rt_rq, rq) {
 		array = &rt_rq->active;
 		idx = sched_find_first_bit(array->bitmap);
 next_idx:
 		if (idx >= MAX_RT_PRIO)
 			continue;
 		if (next && next->prio <= idx)
 			continue;
 		list_for_each_entry(rt_se, array->queue + idx, run_list) {
 			struct task_struct *p;
 			if (!rt_entity_is_task(rt_se))
 				continue;
 			p = rt_task_of(rt_se);
 			if (pick_rt_task(rq, p, cpu)) {
 				next = p;
 				break;
 			}
 		}
 		if (!next) {
 			idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1);
 			goto next_idx;
 		}
 	}
 	return next;
 }
 static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask);
 static int find_lowest_rq(struct task_struct *task)
 {
 	struct sched_domain *sd;
 	struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
 	int this_cpu = smp_processor_id();
 	int cpu      = task_cpu(task);
 	/* Make sure the mask is initialized first */
 	if (unlikely(!lowest_mask))
 		return -1;
 	if (task->nr_cpus_allowed == 1)
 		return -1; /* No other targets possible */
 	if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask))
 		return -1; /* No targets found */
 	/*
 	 * At this point we have built a mask of cpus representing the
 	 * lowest priority tasks in the system.  Now we want to elect
 	 * the best one based on our affinity and topology.
 	 *
 	 * We prioritize the last cpu that the task executed on since
 	 * it is most likely cache-hot in that location.
 	 */
 	if (cpumask_test_cpu(cpu, lowest_mask))
 		return cpu;
 	/*
 	 * Otherwise, we consult the sched_domains span maps to figure
 	 * out which cpu is logically closest to our hot cache data.
 	 */
 	if (!cpumask_test_cpu(this_cpu, lowest_mask))
 		this_cpu = -1; /* Skip this_cpu opt if not among lowest */
 	rcu_read_lock();
 	for_each_domain(cpu, sd) {
 		if (sd->flags & SD_WAKE_AFFINE) {
 			int best_cpu;
 			/*
 			 * "this_cpu" is cheaper to preempt than a
 			 * remote processor.
 			 */
 			if (this_cpu != -1 &&
 			    cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
 				rcu_read_unlock();
 				return this_cpu;
 			}
 			best_cpu = cpumask_first_and(lowest_mask,
 						     sched_domain_span(sd));
 			if (best_cpu < nr_cpu_ids) {
 				rcu_read_unlock();
 				return best_cpu;
 			}
 		}
 	}
 	rcu_read_unlock();
 	/*
 	 * And finally, if there were no matches within the domains
 	 * just give the caller *something* to work with from the compatible
 	 * locations.
 	 */
 	if (this_cpu != -1)
 		return this_cpu;
 	cpu = cpumask_any(lowest_mask);
 	if (cpu < nr_cpu_ids)
 		return cpu;
 	return -1;
 }
 /* Will lock the rq it finds */
 static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
 {
 	struct rq *lowest_rq = NULL;
 	int tries;
 	int cpu;
 	for (tries = 0; tries < RT_MAX_TRIES; tries++) {
 		cpu = find_lowest_rq(task);
 		if ((cpu == -1) || (cpu == rq->cpu))
 			break;
 		lowest_rq = cpu_rq(cpu);
 		/* if the prio of this runqueue changed, try again */
 		if (double_lock_balance(rq, lowest_rq)) {
 			/*
 			 * We had to unlock the run queue. In
 			 * the mean time, task could have
 			 * migrated already or had its affinity changed.
 			 * Also make sure that it wasn't scheduled on its rq.
 			 */
 			if (unlikely(task_rq(task) != rq ||
 				     !cpumask_test_cpu(lowest_rq->cpu,
 						       tsk_cpus_allowed(task)) ||
 				     task_running(rq, task) ||
 				     !task->on_rq)) {
 				double_unlock_balance(rq, lowest_rq);
 				lowest_rq = NULL;
 				break;
 			}
 		}
 		/* If this rq is still suitable use it. */
 		if (lowest_rq->rt.highest_prio.curr > task->prio)
 			break;
 		/* try again */
 		double_unlock_balance(rq, lowest_rq);
 		lowest_rq = NULL;
 	}
 	return lowest_rq;
 }
 static struct task_struct *pick_next_pushable_task(struct rq *rq)
 {
 	struct task_struct *p;
 	if (!has_pushable_tasks(rq))
 		return NULL;
 	p = plist_first_entry(&rq->rt.pushable_tasks,
 			      struct task_struct, pushable_tasks);
 	BUG_ON(rq->cpu != task_cpu(p));
 	BUG_ON(task_current(rq, p));
 	BUG_ON(p->nr_cpus_allowed <= 1);
 	BUG_ON(!p->on_rq);
 	BUG_ON(!rt_task(p));
 	return p;
 }
 /*
  * If the current CPU has more than one RT task, see if the non
  * running task can migrate over to a CPU that is running a task
  * of lesser priority.
  */
 static int push_rt_task(struct rq *rq)
 {
 	struct task_struct *next_task;
 	struct rq *lowest_rq;
 	int ret = 0;
 	if (!rq->rt.overloaded)
 		return 0;
 	next_task = pick_next_pushable_task(rq);
 	if (!next_task)
 		return 0;
 retry:
 	if (unlikely(next_task == rq->curr)) {
 		WARN_ON(1);
 		return 0;
 	}
 	/*
 	 * It's possible that the next_task slipped in of
 	 * higher priority than current. If that's the case
 	 * just reschedule current.
 	 */
 	if (unlikely(next_task->prio < rq->curr->prio)) {
 		resched_task(rq->curr);
 		return 0;
 	}
 	/* We might release rq lock */
 	get_task_struct(next_task);
 	/* find_lock_lowest_rq locks the rq if found */
 	lowest_rq = find_lock_lowest_rq(next_task, rq);
 	if (!lowest_rq) {
 		struct task_struct *task;
 		/*
 		 * find_lock_lowest_rq releases rq->lock
 		 * so it is possible that next_task has migrated.
 		 *
 		 * We need to make sure that the task is still on the same
 		 * run-queue and is also still the next task eligible for
 		 * pushing.
 		 */
 		task = pick_next_pushable_task(rq);
 		if (task_cpu(next_task) == rq->cpu && task == next_task) {
 			/*
 			 * The task hasn't migrated, and is still the next
 			 * eligible task, but we failed to find a run-queue
 			 * to push it to.  Do not retry in this case, since
 			 * other cpus will pull from us when ready.
 			 */
 			goto out;
 		}
 		if (!task)
 			/* No more tasks, just exit */
 			goto out;
 		/*
 		 * Something has shifted, try again.
 		 */
 		put_task_struct(next_task);
 		next_task = task;
 		goto retry;
 	}
 	deactivate_task(rq, next_task, 0);
 	set_task_cpu(next_task, lowest_rq->cpu);
 	activate_task(lowest_rq, next_task, 0);
 	ret = 1;
 	resched_task(lowest_rq->curr);
 	double_unlock_balance(rq, lowest_rq);
 out:
 	put_task_struct(next_task);
 	return ret;
 }
 static void push_rt_tasks(struct rq *rq)
 {
 	/* push_rt_task will return true if it moved an RT */
 	while (push_rt_task(rq))
 		;
 }
 static int pull_rt_task(struct rq *this_rq)
 {
 	int this_cpu = this_rq->cpu, ret = 0, cpu;
 	struct task_struct *p;
 	struct rq *src_rq;
 	if (likely(!rt_overloaded(this_rq)))
 		return 0;
 	for_each_cpu(cpu, this_rq->rd->rto_mask) {
 		if (this_cpu == cpu)
 			continue;
 		src_rq = cpu_rq(cpu);
 		/*
 		 * Don't bother taking the src_rq->lock if the next highest
 		 * task is known to be lower-priority than our current task.
 		 * This may look racy, but if this value is about to go
 		 * logically higher, the src_rq will push this task away.
 		 * And if its going logically lower, we do not care
 		 */
 		if (src_rq->rt.highest_prio.next >=
 		    this_rq->rt.highest_prio.curr)
 			continue;
 		/*
 		 * We can potentially drop this_rq's lock in
 		 * double_lock_balance, and another CPU could
 		 * alter this_rq
 		 */
 		double_lock_balance(this_rq, src_rq);
 		/*
 		 * Are there still pullable RT tasks?
 		 */
 		if (src_rq->rt.rt_nr_running <= 1)
 			goto skip;
 		p = pick_next_highest_task_rt(src_rq, this_cpu);
 		/*
 		 * Do we have an RT task that preempts
 		 * the to-be-scheduled task?
 		 */
 		if (p && (p->prio < this_rq->rt.highest_prio.curr)) {
 			WARN_ON(p == src_rq->curr);
 			WARN_ON(!p->on_rq);
 			/*
 			 * There's a chance that p is higher in priority
 			 * than what's currently running on its cpu.
 			 * This is just that p is wakeing up and hasn't
 			 * had a chance to schedule. We only pull
 			 * p if it is lower in priority than the
 			 * current task on the run queue
 			 */
 			if (p->prio < src_rq->curr->prio)
 				goto skip;
 			ret = 1;
 			deactivate_task(src_rq, p, 0);
 			set_task_cpu(p, this_cpu);
 			activate_task(this_rq, p, 0);
 			/*
 			 * We continue with the search, just in
 			 * case there's an even higher prio task
 			 * in another runqueue. (low likelihood
 			 * but possible)
 			 */
 		}
 skip:
 		double_unlock_balance(this_rq, src_rq);
 	}
 	return ret;
 }
 static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
 {
 	/* Try to pull RT tasks here if we lower this rq's prio */
 	if (rq->rt.highest_prio.curr > prev->prio)
 		pull_rt_task(rq);
 }
 static void post_schedule_rt(struct rq *rq)
 {
 	push_rt_tasks(rq);
 }
 /*
  * If we are not running and we are not going to reschedule soon, we should
  * try to push tasks away now
  */
 static void task_woken_rt(struct rq *rq, struct task_struct *p)
 {
 	if (!task_running(rq, p) &&
 	    !test_tsk_need_resched(rq->curr) &&
 	    has_pushable_tasks(rq) &&
 	    p->nr_cpus_allowed > 1 &&
 	    rt_task(rq->curr) &&
 	    (rq->curr->nr_cpus_allowed < 2 ||
 	     rq->curr->prio <= p->prio))
 		push_rt_tasks(rq);
 }
 static void set_cpus_allowed_rt(struct task_struct *p,
 				const struct cpumask *new_mask)
 {
 	struct rq *rq;
 	int weight;
 	BUG_ON(!rt_task(p));
 	if (!p->on_rq)
 		return;
 	weight = cpumask_weight(new_mask);
 	/*
 	 * Only update if the process changes its state from whether it
 	 * can migrate or not.
 	 */
 	if ((p->nr_cpus_allowed > 1) == (weight > 1))
 		return;
 	rq = task_rq(p);
 	/*
 	 * The process used to be able to migrate OR it can now migrate
 	 */
 	if (weight <= 1) {
 		if (!task_current(rq, p))
 			dequeue_pushable_task(rq, p);
 		BUG_ON(!rq->rt.rt_nr_migratory);
 		rq->rt.rt_nr_migratory--;
 	} else {
 		if (!task_current(rq, p))
 			enqueue_pushable_task(rq, p);
 		rq->rt.rt_nr_migratory++;
 	}
 	update_rt_migration(&rq->rt);
 }
 /* Assumes rq->lock is held */
 static void rq_online_rt(struct rq *rq)
 {
 	if (rq->rt.overloaded)
 		rt_set_overload(rq);
 	__enable_runtime(rq);
 	cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr);
 }
 /* Assumes rq->lock is held */
 static void rq_offline_rt(struct rq *rq)
 {
 	if (rq->rt.overloaded)
 		rt_clear_overload(rq);
 	__disable_runtime(rq);
 	cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID);
 }
 /*
  * When switch from the rt queue, we bring ourselves to a position
  * that we might want to pull RT tasks from other runqueues.
  */
 static void switched_from_rt(struct rq *rq, struct task_struct *p)
 {
 	/*
 	 * If there are other RT tasks then we will reschedule
 	 * and the scheduling of the other RT tasks will handle
 	 * the balancing. But if we are the last RT task
 	 * we may need to handle the pulling of RT tasks
 	 * now.
 	 */
-	if (p->on_rq && !rq->rt.rt_nr_running)
+	if (!p->on_rq || rq->rt.rt_nr_running)
-		pull_rt_task(rq);
+		return;
+	if (pull_rt_task(rq))
+		resched_task(rq->curr);
 }
 void init_sched_rt_class(void)
 {
 	unsigned int i;
 	for_each_possible_cpu(i) {
 		zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
 					GFP_KERNEL, cpu_to_node(i));
 	}
 }
 #endif /* CONFIG_SMP */
 /*
  * When switching a task to RT, we may overload the runqueue
  * with RT tasks. In this case we try to push them off to
  * other runqueues.
  */
 static void switched_to_rt(struct rq *rq, struct task_struct *p)
 {
 	int check_resched = 1;
 	/*
 	 * If we are already running, then there's nothing
 	 * that needs to be done. But if we are not running
 	 * we may need to preempt the current running task.
 	 * If that current running task is also an RT task
 	 * then see if we can move to another run queue.
 	 */
 	if (p->on_rq && rq->curr != p) {
 #ifdef CONFIG_SMP
 		if (rq->rt.overloaded && push_rt_task(rq) &&
 		    /* Don't resched if we changed runqueues */
 		    rq != task_rq(p))
 			check_resched = 0;
 #endif /* CONFIG_SMP */
 		if (check_resched && p->prio < rq->curr->prio)
 			resched_task(rq->curr);
 	}
 }
 /*
  * Priority of the task has changed. This may cause
  * us to initiate a push or pull.
  */
 static void
 prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 {
 	if (!p->on_rq)
 		return;
 	if (rq->curr == p) {
 #ifdef CONFIG_SMP
 		/*
 		 * If our priority decreases while running, we
 		 * may need to pull tasks to this runqueue.
 		 */
 		if (oldprio < p->prio)
 			pull_rt_task(rq);
 		/*
 		 * If there's a higher priority task waiting to run
 		 * then reschedule. Note, the above pull_rt_task
 		 * can release the rq lock and p could migrate.
 		 * Only reschedule if p is still on the same runqueue.
 		 */
 		if (p->prio > rq->rt.highest_prio.curr && rq->curr == p)
 			resched_task(p);
 #else
 		/* For UP simply resched on drop of prio */
 		if (oldprio < p->prio)
 			resched_task(p);
 #endif /* CONFIG_SMP */
 	} else {
 		/*
 		 * This task is not running, but if it is
 		 * greater than the current running task
 		 * then reschedule.
 		 */
 		if (p->prio < rq->curr->prio)
 			resched_task(rq->curr);
 	}
 }
 static void watchdog(struct rq *rq, struct task_struct *p)
 {
 	unsigned long soft, hard;
 	/* max may change after cur was read, this will be fixed next tick */
 	soft = task_rlimit(p, RLIMIT_RTTIME);
 	hard = task_rlimit_max(p, RLIMIT_RTTIME);
 	if (soft != RLIM_INFINITY) {
 		unsigned long next;
 		p->rt.timeout++;
 		next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
 		if (p->rt.timeout > next)
 			p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
 	}
 }
 static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
 {
 	struct sched_rt_entity *rt_se = &p->rt;
 	update_curr_rt(rq);
 	watchdog(rq, p);
 	/*
 	 * RR tasks need a special form of timeslice management.
 	 * FIFO tasks have no timeslices.
 	 */
 	if (p->policy != SCHED_RR)
 		return;
 	if (--p->rt.time_slice)
 		return;
 	p->rt.time_slice = RR_TIMESLICE;
 	/*
 	 * Requeue to the end of queue if we (and all of our ancestors) are the
 	 * only element on the queue
 	 */
 	for_each_sched_rt_entity(rt_se) {
 		if (rt_se->run_list.prev != rt_se->run_list.next) {
 			requeue_task_rt(rq, p, 0);
 			set_tsk_need_resched(p);
 			return;
 		}
 	}
 }
 static void set_curr_task_rt(struct rq *rq)
 {
 	struct task_struct *p = rq->curr;
 	p->se.exec_start = rq->clock_task;
 	/* The running task is never eligible for pushing */
 	dequeue_pushable_task(rq, p);
 }
 static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
 {
 	/*
 	 * Time slice is 0 for SCHED_FIFO tasks
 	 */
 	if (task->policy == SCHED_RR)
 		return RR_TIMESLICE;
 	else
 		return 0;
 }
 const struct sched_class rt_sched_class = {
 	.next			= &fair_sched_class,
 	.enqueue_task		= enqueue_task_rt,
 	.dequeue_task		= dequeue_task_rt,
 	.yield_task		= yield_task_rt,
 	.check_preempt_curr	= check_preempt_curr_rt,
 	.pick_next_task		= pick_next_task_rt,
 	.put_prev_task		= put_prev_task_rt,
 #ifdef CONFIG_SMP
 	.select_task_rq		= select_task_rq_rt,
 	.set_cpus_allowed       = set_cpus_allowed_rt,
 	.rq_online              = rq_online_rt,
 	.rq_offline             = rq_offline_rt,
 	.pre_schedule		= pre_schedule_rt,
 	.post_schedule		= post_schedule_rt,
 	.task_woken		= task_woken_rt,
 	.switched_from		= switched_from_rt,
 #endif
 	.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,
 };
 #ifdef CONFIG_SCHED_DEBUG
 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
 void print_rt_stats(struct seq_file *m, int cpu)
 {
 	rt_rq_iter_t iter;
 	struct rt_rq *rt_rq;
 	rcu_read_lock();
 	for_each_rt_rq(rt_rq, iter, cpu_rq(cpu))
 		print_rt_rq(m, cpu, rt_rq);
 	rcu_read_unlock();
 }
 #endif /* CONFIG_SCHED_DEBUG */