Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR |
| 3 | * policies) |
| 4 | */ |
| 5 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 6 | static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) |
| 7 | { |
| 8 | return container_of(rt_se, struct task_struct, rt); |
| 9 | } |
| 10 | |
| 11 | #ifdef CONFIG_RT_GROUP_SCHED |
| 12 | |
| 13 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
| 14 | { |
| 15 | return rt_rq->rq; |
| 16 | } |
| 17 | |
| 18 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) |
| 19 | { |
| 20 | return rt_se->rt_rq; |
| 21 | } |
| 22 | |
| 23 | #else /* CONFIG_RT_GROUP_SCHED */ |
| 24 | |
| 25 | static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) |
| 26 | { |
| 27 | return container_of(rt_rq, struct rq, rt); |
| 28 | } |
| 29 | |
| 30 | static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) |
| 31 | { |
| 32 | struct task_struct *p = rt_task_of(rt_se); |
| 33 | struct rq *rq = task_rq(p); |
| 34 | |
| 35 | return &rq->rt; |
| 36 | } |
| 37 | |
| 38 | #endif /* CONFIG_RT_GROUP_SCHED */ |
| 39 | |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 40 | #ifdef CONFIG_SMP |
Ingo Molnar | 84de427 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 41 | |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 42 | static inline int rt_overloaded(struct rq *rq) |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 43 | { |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 44 | return atomic_read(&rq->rd->rto_count); |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 45 | } |
Ingo Molnar | 84de427 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 46 | |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 47 | static inline void rt_set_overload(struct rq *rq) |
| 48 | { |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 49 | if (!rq->online) |
| 50 | return; |
| 51 | |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 52 | cpumask_set_cpu(rq->cpu, rq->rd->rto_mask); |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 53 | /* |
| 54 | * Make sure the mask is visible before we set |
| 55 | * the overload count. That is checked to determine |
| 56 | * if we should look at the mask. It would be a shame |
| 57 | * if we looked at the mask, but the mask was not |
| 58 | * updated yet. |
| 59 | */ |
| 60 | wmb(); |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 61 | atomic_inc(&rq->rd->rto_count); |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 62 | } |
Ingo Molnar | 84de427 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 63 | |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 64 | static inline void rt_clear_overload(struct rq *rq) |
| 65 | { |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 66 | if (!rq->online) |
| 67 | return; |
| 68 | |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 69 | /* the order here really doesn't matter */ |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 70 | atomic_dec(&rq->rd->rto_count); |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 71 | cpumask_clear_cpu(rq->cpu, rq->rd->rto_mask); |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 72 | } |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 73 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 74 | static void update_rt_migration(struct rt_rq *rt_rq) |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 75 | { |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 76 | if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) { |
| 77 | if (!rt_rq->overloaded) { |
| 78 | rt_set_overload(rq_of_rt_rq(rt_rq)); |
| 79 | rt_rq->overloaded = 1; |
Gregory Haskins | cdc8eb9 | 2008-01-25 21:08:23 +0100 | [diff] [blame] | 80 | } |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 81 | } else if (rt_rq->overloaded) { |
| 82 | rt_clear_overload(rq_of_rt_rq(rt_rq)); |
| 83 | rt_rq->overloaded = 0; |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 84 | } |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 85 | } |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 86 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 87 | static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 88 | { |
| 89 | if (rt_se->nr_cpus_allowed > 1) |
| 90 | rt_rq->rt_nr_migratory++; |
| 91 | |
| 92 | update_rt_migration(rt_rq); |
| 93 | } |
| 94 | |
| 95 | static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 96 | { |
| 97 | if (rt_se->nr_cpus_allowed > 1) |
| 98 | rt_rq->rt_nr_migratory--; |
| 99 | |
| 100 | update_rt_migration(rt_rq); |
| 101 | } |
| 102 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 103 | static void enqueue_pushable_task(struct rq *rq, struct task_struct *p) |
| 104 | { |
| 105 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); |
| 106 | plist_node_init(&p->pushable_tasks, p->prio); |
| 107 | plist_add(&p->pushable_tasks, &rq->rt.pushable_tasks); |
| 108 | } |
| 109 | |
| 110 | static void dequeue_pushable_task(struct rq *rq, struct task_struct *p) |
| 111 | { |
| 112 | plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks); |
| 113 | } |
| 114 | |
| 115 | #else |
| 116 | |
Gregory Haskins | b07430a | 2009-01-14 08:55:39 -0500 | [diff] [blame] | 117 | static inline |
| 118 | void enqueue_pushable_task(struct rq *rq, struct task_struct *p) {} |
| 119 | static inline |
| 120 | void dequeue_pushable_task(struct rq *rq, struct task_struct *p) {} |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 121 | static inline |
| 122 | void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} |
| 123 | static inline |
| 124 | void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 125 | |
Steven Rostedt | 4fd2917 | 2008-01-25 21:08:06 +0100 | [diff] [blame] | 126 | #endif /* CONFIG_SMP */ |
| 127 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 128 | static inline int on_rt_rq(struct sched_rt_entity *rt_se) |
| 129 | { |
| 130 | return !list_empty(&rt_se->run_list); |
| 131 | } |
| 132 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 133 | #ifdef CONFIG_RT_GROUP_SCHED |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 134 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 135 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 136 | { |
| 137 | if (!rt_rq->tg) |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 138 | return RUNTIME_INF; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 139 | |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 140 | return rt_rq->rt_runtime; |
| 141 | } |
| 142 | |
| 143 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) |
| 144 | { |
| 145 | return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 146 | } |
| 147 | |
| 148 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
Bharata B Rao | 80f40ee | 2008-12-15 11:56:48 +0530 | [diff] [blame] | 149 | list_for_each_entry_rcu(rt_rq, &rq->leaf_rt_rq_list, leaf_rt_rq_list) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 150 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 151 | #define for_each_sched_rt_entity(rt_se) \ |
| 152 | for (; rt_se; rt_se = rt_se->parent) |
| 153 | |
| 154 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) |
| 155 | { |
| 156 | return rt_se->my_q; |
| 157 | } |
| 158 | |
| 159 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se); |
| 160 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se); |
| 161 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 162 | static void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 163 | { |
Dario Faggioli | f6121f4 | 2008-10-03 17:40:46 +0200 | [diff] [blame] | 164 | struct task_struct *curr = rq_of_rt_rq(rt_rq)->curr; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 165 | struct sched_rt_entity *rt_se = rt_rq->rt_se; |
| 166 | |
Dario Faggioli | f6121f4 | 2008-10-03 17:40:46 +0200 | [diff] [blame] | 167 | if (rt_rq->rt_nr_running) { |
| 168 | if (rt_se && !on_rt_rq(rt_se)) |
| 169 | enqueue_rt_entity(rt_se); |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 170 | if (rt_rq->highest_prio.curr < curr->prio) |
Peter Zijlstra | 1020387 | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 171 | resched_task(curr); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 172 | } |
| 173 | } |
| 174 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 175 | static void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 176 | { |
| 177 | struct sched_rt_entity *rt_se = rt_rq->rt_se; |
| 178 | |
| 179 | if (rt_se && on_rt_rq(rt_se)) |
| 180 | dequeue_rt_entity(rt_se); |
| 181 | } |
| 182 | |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 183 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
| 184 | { |
| 185 | return rt_rq->rt_throttled && !rt_rq->rt_nr_boosted; |
| 186 | } |
| 187 | |
| 188 | static int rt_se_boosted(struct sched_rt_entity *rt_se) |
| 189 | { |
| 190 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
| 191 | struct task_struct *p; |
| 192 | |
| 193 | if (rt_rq) |
| 194 | return !!rt_rq->rt_nr_boosted; |
| 195 | |
| 196 | p = rt_task_of(rt_se); |
| 197 | return p->prio != p->normal_prio; |
| 198 | } |
| 199 | |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 200 | #ifdef CONFIG_SMP |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 201 | static inline const struct cpumask *sched_rt_period_mask(void) |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 202 | { |
| 203 | return cpu_rq(smp_processor_id())->rd->span; |
| 204 | } |
| 205 | #else |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 206 | static inline const struct cpumask *sched_rt_period_mask(void) |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 207 | { |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 208 | return cpu_online_mask; |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 209 | } |
| 210 | #endif |
| 211 | |
| 212 | static inline |
| 213 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) |
| 214 | { |
| 215 | return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu]; |
| 216 | } |
| 217 | |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 218 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
| 219 | { |
| 220 | return &rt_rq->tg->rt_bandwidth; |
| 221 | } |
| 222 | |
Dhaval Giani | 55e12e5 | 2008-06-24 23:39:43 +0530 | [diff] [blame] | 223 | #else /* !CONFIG_RT_GROUP_SCHED */ |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 224 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 225 | static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 226 | { |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 227 | return rt_rq->rt_runtime; |
| 228 | } |
| 229 | |
| 230 | static inline u64 sched_rt_period(struct rt_rq *rt_rq) |
| 231 | { |
| 232 | return ktime_to_ns(def_rt_bandwidth.rt_period); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 233 | } |
| 234 | |
| 235 | #define for_each_leaf_rt_rq(rt_rq, rq) \ |
| 236 | for (rt_rq = &rq->rt; rt_rq; rt_rq = NULL) |
| 237 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 238 | #define for_each_sched_rt_entity(rt_se) \ |
| 239 | for (; rt_se; rt_se = NULL) |
| 240 | |
| 241 | static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) |
| 242 | { |
| 243 | return NULL; |
| 244 | } |
| 245 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 246 | static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 247 | { |
John Blackwood | f3ade83 | 2008-08-26 15:09:43 -0400 | [diff] [blame] | 248 | if (rt_rq->rt_nr_running) |
| 249 | resched_task(rq_of_rt_rq(rt_rq)->curr); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 250 | } |
| 251 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 252 | static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 253 | { |
| 254 | } |
| 255 | |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 256 | static inline int rt_rq_throttled(struct rt_rq *rt_rq) |
| 257 | { |
| 258 | return rt_rq->rt_throttled; |
| 259 | } |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 260 | |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 261 | static inline const struct cpumask *sched_rt_period_mask(void) |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 262 | { |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 263 | return cpu_online_mask; |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 264 | } |
| 265 | |
| 266 | static inline |
| 267 | struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) |
| 268 | { |
| 269 | return &cpu_rq(cpu)->rt; |
| 270 | } |
| 271 | |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 272 | static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) |
| 273 | { |
| 274 | return &def_rt_bandwidth; |
| 275 | } |
| 276 | |
Dhaval Giani | 55e12e5 | 2008-06-24 23:39:43 +0530 | [diff] [blame] | 277 | #endif /* CONFIG_RT_GROUP_SCHED */ |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 278 | |
Peter Zijlstra | b79f383 | 2008-06-19 14:22:25 +0200 | [diff] [blame] | 279 | #ifdef CONFIG_SMP |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 280 | /* |
| 281 | * We ran out of runtime, see if we can borrow some from our neighbours. |
| 282 | */ |
Peter Zijlstra | b79f383 | 2008-06-19 14:22:25 +0200 | [diff] [blame] | 283 | static int do_balance_runtime(struct rt_rq *rt_rq) |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 284 | { |
| 285 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
| 286 | struct root_domain *rd = cpu_rq(smp_processor_id())->rd; |
| 287 | int i, weight, more = 0; |
| 288 | u64 rt_period; |
| 289 | |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 290 | weight = cpumask_weight(rd->span); |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 291 | |
| 292 | spin_lock(&rt_b->rt_runtime_lock); |
| 293 | rt_period = ktime_to_ns(rt_b->rt_period); |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 294 | for_each_cpu(i, rd->span) { |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 295 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
| 296 | s64 diff; |
| 297 | |
| 298 | if (iter == rt_rq) |
| 299 | continue; |
| 300 | |
| 301 | spin_lock(&iter->rt_runtime_lock); |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 302 | /* |
| 303 | * Either all rqs have inf runtime and there's nothing to steal |
| 304 | * or __disable_runtime() below sets a specific rq to inf to |
| 305 | * indicate its been disabled and disalow stealing. |
| 306 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 307 | if (iter->rt_runtime == RUNTIME_INF) |
| 308 | goto next; |
| 309 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 310 | /* |
| 311 | * From runqueues with spare time, take 1/n part of their |
| 312 | * spare time, but no more than our period. |
| 313 | */ |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 314 | diff = iter->rt_runtime - iter->rt_time; |
| 315 | if (diff > 0) { |
Peter Zijlstra | 58838cf | 2008-07-24 12:43:13 +0200 | [diff] [blame] | 316 | diff = div_u64((u64)diff, weight); |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 317 | if (rt_rq->rt_runtime + diff > rt_period) |
| 318 | diff = rt_period - rt_rq->rt_runtime; |
| 319 | iter->rt_runtime -= diff; |
| 320 | rt_rq->rt_runtime += diff; |
| 321 | more = 1; |
| 322 | if (rt_rq->rt_runtime == rt_period) { |
| 323 | spin_unlock(&iter->rt_runtime_lock); |
| 324 | break; |
| 325 | } |
| 326 | } |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 327 | next: |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 328 | spin_unlock(&iter->rt_runtime_lock); |
| 329 | } |
| 330 | spin_unlock(&rt_b->rt_runtime_lock); |
| 331 | |
| 332 | return more; |
| 333 | } |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 334 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 335 | /* |
| 336 | * Ensure this RQ takes back all the runtime it lend to its neighbours. |
| 337 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 338 | static void __disable_runtime(struct rq *rq) |
| 339 | { |
| 340 | struct root_domain *rd = rq->rd; |
| 341 | struct rt_rq *rt_rq; |
| 342 | |
| 343 | if (unlikely(!scheduler_running)) |
| 344 | return; |
| 345 | |
| 346 | for_each_leaf_rt_rq(rt_rq, rq) { |
| 347 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
| 348 | s64 want; |
| 349 | int i; |
| 350 | |
| 351 | spin_lock(&rt_b->rt_runtime_lock); |
| 352 | spin_lock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 353 | /* |
| 354 | * Either we're all inf and nobody needs to borrow, or we're |
| 355 | * already disabled and thus have nothing to do, or we have |
| 356 | * exactly the right amount of runtime to take out. |
| 357 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 358 | if (rt_rq->rt_runtime == RUNTIME_INF || |
| 359 | rt_rq->rt_runtime == rt_b->rt_runtime) |
| 360 | goto balanced; |
| 361 | spin_unlock(&rt_rq->rt_runtime_lock); |
| 362 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 363 | /* |
| 364 | * Calculate the difference between what we started out with |
| 365 | * and what we current have, that's the amount of runtime |
| 366 | * we lend and now have to reclaim. |
| 367 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 368 | want = rt_b->rt_runtime - rt_rq->rt_runtime; |
| 369 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 370 | /* |
| 371 | * Greedy reclaim, take back as much as we can. |
| 372 | */ |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 373 | for_each_cpu(i, rd->span) { |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 374 | struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); |
| 375 | s64 diff; |
| 376 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 377 | /* |
| 378 | * Can't reclaim from ourselves or disabled runqueues. |
| 379 | */ |
Peter Zijlstra | f1679d0 | 2008-08-14 15:49:00 +0200 | [diff] [blame] | 380 | if (iter == rt_rq || iter->rt_runtime == RUNTIME_INF) |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 381 | continue; |
| 382 | |
| 383 | spin_lock(&iter->rt_runtime_lock); |
| 384 | if (want > 0) { |
| 385 | diff = min_t(s64, iter->rt_runtime, want); |
| 386 | iter->rt_runtime -= diff; |
| 387 | want -= diff; |
| 388 | } else { |
| 389 | iter->rt_runtime -= want; |
| 390 | want -= want; |
| 391 | } |
| 392 | spin_unlock(&iter->rt_runtime_lock); |
| 393 | |
| 394 | if (!want) |
| 395 | break; |
| 396 | } |
| 397 | |
| 398 | spin_lock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 399 | /* |
| 400 | * We cannot be left wanting - that would mean some runtime |
| 401 | * leaked out of the system. |
| 402 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 403 | BUG_ON(want); |
| 404 | balanced: |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 405 | /* |
| 406 | * Disable all the borrow logic by pretending we have inf |
| 407 | * runtime - in which case borrowing doesn't make sense. |
| 408 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 409 | rt_rq->rt_runtime = RUNTIME_INF; |
| 410 | spin_unlock(&rt_rq->rt_runtime_lock); |
| 411 | spin_unlock(&rt_b->rt_runtime_lock); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | static void disable_runtime(struct rq *rq) |
| 416 | { |
| 417 | unsigned long flags; |
| 418 | |
| 419 | spin_lock_irqsave(&rq->lock, flags); |
| 420 | __disable_runtime(rq); |
| 421 | spin_unlock_irqrestore(&rq->lock, flags); |
| 422 | } |
| 423 | |
| 424 | static void __enable_runtime(struct rq *rq) |
| 425 | { |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 426 | struct rt_rq *rt_rq; |
| 427 | |
| 428 | if (unlikely(!scheduler_running)) |
| 429 | return; |
| 430 | |
Peter Zijlstra | 78333cd | 2008-09-23 15:33:43 +0200 | [diff] [blame] | 431 | /* |
| 432 | * Reset each runqueue's bandwidth settings |
| 433 | */ |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 434 | for_each_leaf_rt_rq(rt_rq, rq) { |
| 435 | struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); |
| 436 | |
| 437 | spin_lock(&rt_b->rt_runtime_lock); |
| 438 | spin_lock(&rt_rq->rt_runtime_lock); |
| 439 | rt_rq->rt_runtime = rt_b->rt_runtime; |
| 440 | rt_rq->rt_time = 0; |
Zhang, Yanmin | baf2573 | 2008-09-09 11:26:33 +0800 | [diff] [blame] | 441 | rt_rq->rt_throttled = 0; |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 442 | spin_unlock(&rt_rq->rt_runtime_lock); |
| 443 | spin_unlock(&rt_b->rt_runtime_lock); |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | static void enable_runtime(struct rq *rq) |
| 448 | { |
| 449 | unsigned long flags; |
| 450 | |
| 451 | spin_lock_irqsave(&rq->lock, flags); |
| 452 | __enable_runtime(rq); |
| 453 | spin_unlock_irqrestore(&rq->lock, flags); |
| 454 | } |
| 455 | |
Peter Zijlstra | eff6549 | 2008-06-19 14:22:26 +0200 | [diff] [blame] | 456 | static int balance_runtime(struct rt_rq *rt_rq) |
| 457 | { |
| 458 | int more = 0; |
| 459 | |
| 460 | if (rt_rq->rt_time > rt_rq->rt_runtime) { |
| 461 | spin_unlock(&rt_rq->rt_runtime_lock); |
| 462 | more = do_balance_runtime(rt_rq); |
| 463 | spin_lock(&rt_rq->rt_runtime_lock); |
| 464 | } |
| 465 | |
| 466 | return more; |
| 467 | } |
Dhaval Giani | 55e12e5 | 2008-06-24 23:39:43 +0530 | [diff] [blame] | 468 | #else /* !CONFIG_SMP */ |
Peter Zijlstra | eff6549 | 2008-06-19 14:22:26 +0200 | [diff] [blame] | 469 | static inline int balance_runtime(struct rt_rq *rt_rq) |
| 470 | { |
| 471 | return 0; |
| 472 | } |
Dhaval Giani | 55e12e5 | 2008-06-24 23:39:43 +0530 | [diff] [blame] | 473 | #endif /* CONFIG_SMP */ |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 474 | |
| 475 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) |
| 476 | { |
| 477 | int i, idle = 1; |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 478 | const struct cpumask *span; |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 479 | |
Peter Zijlstra | 0b148fa | 2008-08-19 12:33:04 +0200 | [diff] [blame] | 480 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 481 | return 1; |
| 482 | |
| 483 | span = sched_rt_period_mask(); |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 484 | for_each_cpu(i, span) { |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 485 | int enqueue = 0; |
| 486 | struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); |
| 487 | struct rq *rq = rq_of_rt_rq(rt_rq); |
| 488 | |
| 489 | spin_lock(&rq->lock); |
| 490 | if (rt_rq->rt_time) { |
| 491 | u64 runtime; |
| 492 | |
| 493 | spin_lock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | eff6549 | 2008-06-19 14:22:26 +0200 | [diff] [blame] | 494 | if (rt_rq->rt_throttled) |
| 495 | balance_runtime(rt_rq); |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 496 | runtime = rt_rq->rt_runtime; |
| 497 | rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); |
| 498 | if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { |
| 499 | rt_rq->rt_throttled = 0; |
| 500 | enqueue = 1; |
| 501 | } |
| 502 | if (rt_rq->rt_time || rt_rq->rt_nr_running) |
| 503 | idle = 0; |
| 504 | spin_unlock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | 8a8cde1 | 2008-06-19 14:22:28 +0200 | [diff] [blame] | 505 | } else if (rt_rq->rt_nr_running) |
| 506 | idle = 0; |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 507 | |
| 508 | if (enqueue) |
| 509 | sched_rt_rq_enqueue(rt_rq); |
| 510 | spin_unlock(&rq->lock); |
| 511 | } |
| 512 | |
| 513 | return idle; |
| 514 | } |
| 515 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 516 | static inline int rt_se_prio(struct sched_rt_entity *rt_se) |
| 517 | { |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 518 | #ifdef CONFIG_RT_GROUP_SCHED |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 519 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
| 520 | |
| 521 | if (rt_rq) |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 522 | return rt_rq->highest_prio.curr; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 523 | #endif |
| 524 | |
| 525 | return rt_task_of(rt_se)->prio; |
| 526 | } |
| 527 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 528 | static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 529 | { |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 530 | u64 runtime = sched_rt_runtime(rt_rq); |
Peter Zijlstra | fa85ae2 | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 531 | |
Peter Zijlstra | fa85ae2 | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 532 | if (rt_rq->rt_throttled) |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 533 | return rt_rq_throttled(rt_rq); |
Peter Zijlstra | fa85ae2 | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 534 | |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 535 | if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq)) |
| 536 | return 0; |
| 537 | |
Peter Zijlstra | b79f383 | 2008-06-19 14:22:25 +0200 | [diff] [blame] | 538 | balance_runtime(rt_rq); |
| 539 | runtime = sched_rt_runtime(rt_rq); |
| 540 | if (runtime == RUNTIME_INF) |
| 541 | return 0; |
Peter Zijlstra | ac086bc | 2008-04-19 19:44:58 +0200 | [diff] [blame] | 542 | |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 543 | if (rt_rq->rt_time > runtime) { |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 544 | rt_rq->rt_throttled = 1; |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 545 | if (rt_rq_throttled(rt_rq)) { |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 546 | sched_rt_rq_dequeue(rt_rq); |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 547 | return 1; |
| 548 | } |
Peter Zijlstra | fa85ae2 | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 549 | } |
| 550 | |
| 551 | return 0; |
| 552 | } |
| 553 | |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 554 | /* |
| 555 | * Update the current task's runtime statistics. Skip current tasks that |
| 556 | * are not in our scheduling class. |
| 557 | */ |
Alexey Dobriyan | a995744 | 2007-10-15 17:00:13 +0200 | [diff] [blame] | 558 | static void update_curr_rt(struct rq *rq) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 559 | { |
| 560 | struct task_struct *curr = rq->curr; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 561 | struct sched_rt_entity *rt_se = &curr->rt; |
| 562 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 563 | u64 delta_exec; |
| 564 | |
| 565 | if (!task_has_rt_policy(curr)) |
| 566 | return; |
| 567 | |
Ingo Molnar | d281918 | 2007-08-09 11:16:47 +0200 | [diff] [blame] | 568 | delta_exec = rq->clock - curr->se.exec_start; |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 569 | if (unlikely((s64)delta_exec < 0)) |
| 570 | delta_exec = 0; |
Ingo Molnar | 6cfb0d5 | 2007-08-02 17:41:40 +0200 | [diff] [blame] | 571 | |
| 572 | schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 573 | |
| 574 | curr->se.sum_exec_runtime += delta_exec; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 575 | account_group_exec_runtime(curr, delta_exec); |
| 576 | |
Ingo Molnar | d281918 | 2007-08-09 11:16:47 +0200 | [diff] [blame] | 577 | curr->se.exec_start = rq->clock; |
Srivatsa Vaddagiri | d842de8 | 2007-12-02 20:04:49 +0100 | [diff] [blame] | 578 | cpuacct_charge(curr, delta_exec); |
Peter Zijlstra | fa85ae2 | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 579 | |
Peter Zijlstra | 0b148fa | 2008-08-19 12:33:04 +0200 | [diff] [blame] | 580 | if (!rt_bandwidth_enabled()) |
| 581 | return; |
| 582 | |
Dhaval Giani | 354d60c | 2008-04-19 19:44:59 +0200 | [diff] [blame] | 583 | for_each_sched_rt_entity(rt_se) { |
| 584 | rt_rq = rt_rq_of_se(rt_se); |
| 585 | |
Peter Zijlstra | cc2991c | 2008-08-19 12:33:03 +0200 | [diff] [blame] | 586 | if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { |
Dimitri Sivanich | e113a74 | 2008-10-31 08:03:41 -0500 | [diff] [blame] | 587 | spin_lock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | cc2991c | 2008-08-19 12:33:03 +0200 | [diff] [blame] | 588 | rt_rq->rt_time += delta_exec; |
| 589 | if (sched_rt_runtime_exceeded(rt_rq)) |
| 590 | resched_task(curr); |
Dimitri Sivanich | e113a74 | 2008-10-31 08:03:41 -0500 | [diff] [blame] | 591 | spin_unlock(&rt_rq->rt_runtime_lock); |
Peter Zijlstra | cc2991c | 2008-08-19 12:33:03 +0200 | [diff] [blame] | 592 | } |
Dhaval Giani | 354d60c | 2008-04-19 19:44:59 +0200 | [diff] [blame] | 593 | } |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 594 | } |
| 595 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 596 | #if defined CONFIG_SMP |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 597 | |
| 598 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu); |
| 599 | |
| 600 | static inline int next_prio(struct rq *rq) |
| 601 | { |
| 602 | struct task_struct *next = pick_next_highest_task_rt(rq, rq->cpu); |
| 603 | |
| 604 | if (next && rt_prio(next->prio)) |
| 605 | return next->prio; |
| 606 | else |
| 607 | return MAX_RT_PRIO; |
| 608 | } |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 609 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 610 | static void |
| 611 | inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) |
Steven Rostedt | 63489e4 | 2008-01-25 21:08:03 +0100 | [diff] [blame] | 612 | { |
Gregory Haskins | 4d98427 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 613 | struct rq *rq = rq_of_rt_rq(rt_rq); |
Gregory Haskins | 4d98427 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 614 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 615 | if (prio < prev_prio) { |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 616 | |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 617 | /* |
| 618 | * If the new task is higher in priority than anything on the |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 619 | * run-queue, we know that the previous high becomes our |
| 620 | * next-highest. |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 621 | */ |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 622 | rt_rq->highest_prio.next = prev_prio; |
| 623 | |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 624 | if (rq->online) |
Gregory Haskins | 4d98427 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 625 | cpupri_set(&rq->rd->cpupri, rq->cpu, prio); |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 626 | |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 627 | } else if (prio == rt_rq->highest_prio.curr) |
| 628 | /* |
| 629 | * If the next task is equal in priority to the highest on |
| 630 | * the run-queue, then we implicitly know that the next highest |
| 631 | * task cannot be any lower than current |
| 632 | */ |
| 633 | rt_rq->highest_prio.next = prio; |
| 634 | else if (prio < rt_rq->highest_prio.next) |
| 635 | /* |
| 636 | * Otherwise, we need to recompute next-highest |
| 637 | */ |
| 638 | rt_rq->highest_prio.next = next_prio(rq); |
Steven Rostedt | 63489e4 | 2008-01-25 21:08:03 +0100 | [diff] [blame] | 639 | } |
| 640 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 641 | static void |
| 642 | dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) |
Steven Rostedt | 63489e4 | 2008-01-25 21:08:03 +0100 | [diff] [blame] | 643 | { |
Gregory Haskins | 4d98427 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 644 | struct rq *rq = rq_of_rt_rq(rt_rq); |
Gregory Haskins | 6e0534f | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 645 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 646 | if (rt_rq->rt_nr_running && (prio <= rt_rq->highest_prio.next)) |
| 647 | rt_rq->highest_prio.next = next_prio(rq); |
| 648 | |
| 649 | if (rq->online && rt_rq->highest_prio.curr != prev_prio) |
| 650 | cpupri_set(&rq->rd->cpupri, rq->cpu, rt_rq->highest_prio.curr); |
| 651 | } |
| 652 | |
| 653 | #else /* CONFIG_SMP */ |
| 654 | |
| 655 | static inline |
| 656 | void inc_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
| 657 | static inline |
| 658 | void dec_rt_prio_smp(struct rt_rq *rt_rq, int prio, int prev_prio) {} |
| 659 | |
| 660 | #endif /* CONFIG_SMP */ |
| 661 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 662 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 663 | static void |
| 664 | inc_rt_prio(struct rt_rq *rt_rq, int prio) |
| 665 | { |
| 666 | int prev_prio = rt_rq->highest_prio.curr; |
Steven Rostedt | 764a9d6 | 2008-01-25 21:08:04 +0100 | [diff] [blame] | 667 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 668 | if (prio < prev_prio) |
| 669 | rt_rq->highest_prio.curr = prio; |
| 670 | |
| 671 | inc_rt_prio_smp(rt_rq, prio, prev_prio); |
| 672 | } |
| 673 | |
| 674 | static void |
| 675 | dec_rt_prio(struct rt_rq *rt_rq, int prio) |
| 676 | { |
| 677 | int prev_prio = rt_rq->highest_prio.curr; |
| 678 | |
| 679 | if (rt_rq->rt_nr_running) { |
| 680 | |
| 681 | WARN_ON(prio < prev_prio); |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 682 | |
| 683 | /* |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 684 | * This may have been our highest task, and therefore |
| 685 | * we may have some recomputation to do |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 686 | */ |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 687 | if (prio == prev_prio) { |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 688 | struct rt_prio_array *array = &rt_rq->active; |
| 689 | |
| 690 | rt_rq->highest_prio.curr = |
Steven Rostedt | 764a9d6 | 2008-01-25 21:08:04 +0100 | [diff] [blame] | 691 | sched_find_first_bit(array->bitmap); |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 692 | } |
| 693 | |
Steven Rostedt | 764a9d6 | 2008-01-25 21:08:04 +0100 | [diff] [blame] | 694 | } else |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 695 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 696 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 697 | dec_rt_prio_smp(rt_rq, prio, prev_prio); |
| 698 | } |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 699 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 700 | #else |
| 701 | |
| 702 | static inline void inc_rt_prio(struct rt_rq *rt_rq, int prio) {} |
| 703 | static inline void dec_rt_prio(struct rt_rq *rt_rq, int prio) {} |
| 704 | |
| 705 | #endif /* CONFIG_SMP || CONFIG_RT_GROUP_SCHED */ |
| 706 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 707 | #ifdef CONFIG_RT_GROUP_SCHED |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 708 | |
| 709 | static void |
| 710 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 711 | { |
| 712 | if (rt_se_boosted(rt_se)) |
| 713 | rt_rq->rt_nr_boosted++; |
| 714 | |
| 715 | if (rt_rq->tg) |
| 716 | start_rt_bandwidth(&rt_rq->tg->rt_bandwidth); |
| 717 | } |
| 718 | |
| 719 | static void |
| 720 | dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 721 | { |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 722 | if (rt_se_boosted(rt_se)) |
| 723 | rt_rq->rt_nr_boosted--; |
| 724 | |
| 725 | WARN_ON(!rt_rq->rt_nr_running && rt_rq->rt_nr_boosted); |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 726 | } |
| 727 | |
| 728 | #else /* CONFIG_RT_GROUP_SCHED */ |
| 729 | |
| 730 | static void |
| 731 | inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 732 | { |
| 733 | start_rt_bandwidth(&def_rt_bandwidth); |
| 734 | } |
| 735 | |
| 736 | static inline |
| 737 | void dec_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) {} |
| 738 | |
| 739 | #endif /* CONFIG_RT_GROUP_SCHED */ |
| 740 | |
| 741 | static inline |
| 742 | void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 743 | { |
| 744 | int prio = rt_se_prio(rt_se); |
| 745 | |
| 746 | WARN_ON(!rt_prio(prio)); |
| 747 | rt_rq->rt_nr_running++; |
| 748 | |
| 749 | inc_rt_prio(rt_rq, prio); |
| 750 | inc_rt_migration(rt_se, rt_rq); |
| 751 | inc_rt_group(rt_se, rt_rq); |
| 752 | } |
| 753 | |
| 754 | static inline |
| 755 | void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) |
| 756 | { |
| 757 | WARN_ON(!rt_prio(rt_se_prio(rt_se))); |
| 758 | WARN_ON(!rt_rq->rt_nr_running); |
| 759 | rt_rq->rt_nr_running--; |
| 760 | |
| 761 | dec_rt_prio(rt_rq, rt_se_prio(rt_se)); |
| 762 | dec_rt_migration(rt_se, rt_rq); |
| 763 | dec_rt_group(rt_se, rt_rq); |
Steven Rostedt | 63489e4 | 2008-01-25 21:08:03 +0100 | [diff] [blame] | 764 | } |
| 765 | |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 766 | static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 767 | { |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 768 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
| 769 | struct rt_prio_array *array = &rt_rq->active; |
| 770 | struct rt_rq *group_rq = group_rt_rq(rt_se); |
Dmitry Adamushko | 20b6331 | 2008-06-11 00:58:30 +0200 | [diff] [blame] | 771 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 772 | |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 773 | /* |
| 774 | * Don't enqueue the group if its throttled, or when empty. |
| 775 | * The latter is a consequence of the former when a child group |
| 776 | * get throttled and the current group doesn't have any other |
| 777 | * active members. |
| 778 | */ |
| 779 | if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 780 | return; |
Steven Rostedt | 63489e4 | 2008-01-25 21:08:03 +0100 | [diff] [blame] | 781 | |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 782 | list_add_tail(&rt_se->run_list, queue); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 783 | __set_bit(rt_se_prio(rt_se), array->bitmap); |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 784 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 785 | inc_rt_tasks(rt_se, rt_rq); |
| 786 | } |
| 787 | |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 788 | static void __dequeue_rt_entity(struct sched_rt_entity *rt_se) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 789 | { |
| 790 | struct rt_rq *rt_rq = rt_rq_of_se(rt_se); |
| 791 | struct rt_prio_array *array = &rt_rq->active; |
| 792 | |
| 793 | list_del_init(&rt_se->run_list); |
| 794 | if (list_empty(array->queue + rt_se_prio(rt_se))) |
| 795 | __clear_bit(rt_se_prio(rt_se), array->bitmap); |
| 796 | |
| 797 | dec_rt_tasks(rt_se, rt_rq); |
| 798 | } |
| 799 | |
| 800 | /* |
| 801 | * Because the prio of an upper entry depends on the lower |
| 802 | * entries, we must remove entries top - down. |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 803 | */ |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 804 | static void dequeue_rt_stack(struct sched_rt_entity *rt_se) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 805 | { |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 806 | struct sched_rt_entity *back = NULL; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 807 | |
Peter Zijlstra | 58d6c2d | 2008-04-19 19:45:00 +0200 | [diff] [blame] | 808 | for_each_sched_rt_entity(rt_se) { |
| 809 | rt_se->back = back; |
| 810 | back = rt_se; |
| 811 | } |
| 812 | |
| 813 | for (rt_se = back; rt_se; rt_se = rt_se->back) { |
| 814 | if (on_rt_rq(rt_se)) |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 815 | __dequeue_rt_entity(rt_se); |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | static void enqueue_rt_entity(struct sched_rt_entity *rt_se) |
| 820 | { |
| 821 | dequeue_rt_stack(rt_se); |
| 822 | for_each_sched_rt_entity(rt_se) |
| 823 | __enqueue_rt_entity(rt_se); |
| 824 | } |
| 825 | |
| 826 | static void dequeue_rt_entity(struct sched_rt_entity *rt_se) |
| 827 | { |
| 828 | dequeue_rt_stack(rt_se); |
| 829 | |
| 830 | for_each_sched_rt_entity(rt_se) { |
| 831 | struct rt_rq *rt_rq = group_rt_rq(rt_se); |
| 832 | |
| 833 | if (rt_rq && rt_rq->rt_nr_running) |
| 834 | __enqueue_rt_entity(rt_se); |
Peter Zijlstra | 58d6c2d | 2008-04-19 19:45:00 +0200 | [diff] [blame] | 835 | } |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 836 | } |
| 837 | |
| 838 | /* |
| 839 | * Adding/removing a task to/from a priority array: |
| 840 | */ |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 841 | static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) |
| 842 | { |
| 843 | struct sched_rt_entity *rt_se = &p->rt; |
| 844 | |
| 845 | if (wakeup) |
| 846 | rt_se->timeout = 0; |
| 847 | |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 848 | enqueue_rt_entity(rt_se); |
Peter Zijlstra | c09595f | 2008-06-27 13:41:14 +0200 | [diff] [blame] | 849 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 850 | if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1) |
| 851 | enqueue_pushable_task(rq, p); |
| 852 | |
Peter Zijlstra | c09595f | 2008-06-27 13:41:14 +0200 | [diff] [blame] | 853 | inc_cpu_load(rq, p->se.load.weight); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 854 | } |
| 855 | |
Ingo Molnar | f02231e | 2007-08-09 11:16:48 +0200 | [diff] [blame] | 856 | static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 857 | { |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 858 | struct sched_rt_entity *rt_se = &p->rt; |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 859 | |
Ingo Molnar | f1e14ef | 2007-08-09 11:16:48 +0200 | [diff] [blame] | 860 | update_curr_rt(rq); |
Peter Zijlstra | ad2a3f1 | 2008-06-19 09:06:57 +0200 | [diff] [blame] | 861 | dequeue_rt_entity(rt_se); |
Peter Zijlstra | c09595f | 2008-06-27 13:41:14 +0200 | [diff] [blame] | 862 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 863 | dequeue_pushable_task(rq, p); |
| 864 | |
Peter Zijlstra | c09595f | 2008-06-27 13:41:14 +0200 | [diff] [blame] | 865 | dec_cpu_load(rq, p->se.load.weight); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 866 | } |
| 867 | |
| 868 | /* |
| 869 | * Put task to the end of the run list without the overhead of dequeue |
| 870 | * followed by enqueue. |
| 871 | */ |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 872 | static void |
| 873 | requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 874 | { |
Ingo Molnar | 1cdad71 | 2008-06-19 09:09:15 +0200 | [diff] [blame] | 875 | if (on_rt_rq(rt_se)) { |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 876 | struct rt_prio_array *array = &rt_rq->active; |
| 877 | struct list_head *queue = array->queue + rt_se_prio(rt_se); |
| 878 | |
| 879 | if (head) |
| 880 | list_move(&rt_se->run_list, queue); |
| 881 | else |
| 882 | list_move_tail(&rt_se->run_list, queue); |
Ingo Molnar | 1cdad71 | 2008-06-19 09:09:15 +0200 | [diff] [blame] | 883 | } |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 884 | } |
| 885 | |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 886 | static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 887 | { |
| 888 | struct sched_rt_entity *rt_se = &p->rt; |
| 889 | struct rt_rq *rt_rq; |
| 890 | |
| 891 | for_each_sched_rt_entity(rt_se) { |
| 892 | rt_rq = rt_rq_of_se(rt_se); |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 893 | requeue_rt_entity(rt_rq, rt_se, head); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 894 | } |
| 895 | } |
| 896 | |
| 897 | static void yield_task_rt(struct rq *rq) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 898 | { |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 899 | requeue_task_rt(rq, rq->curr, 0); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 900 | } |
| 901 | |
Gregory Haskins | e7693a3 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 902 | #ifdef CONFIG_SMP |
Gregory Haskins | 318e089 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 903 | static int find_lowest_rq(struct task_struct *task); |
| 904 | |
Gregory Haskins | e7693a3 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 905 | static int select_task_rq_rt(struct task_struct *p, int sync) |
| 906 | { |
Gregory Haskins | 318e089 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 907 | struct rq *rq = task_rq(p); |
| 908 | |
| 909 | /* |
Steven Rostedt | e1f47d8 | 2008-01-25 21:08:12 +0100 | [diff] [blame] | 910 | * If the current task is an RT task, then |
| 911 | * try to see if we can wake this RT task up on another |
| 912 | * runqueue. Otherwise simply start this RT task |
| 913 | * on its current runqueue. |
| 914 | * |
| 915 | * We want to avoid overloading runqueues. Even if |
| 916 | * the RT task is of higher priority than the current RT task. |
| 917 | * RT tasks behave differently than other tasks. If |
| 918 | * one gets preempted, we try to push it off to another queue. |
| 919 | * So trying to keep a preempting RT task on the same |
| 920 | * cache hot CPU will force the running RT task to |
| 921 | * a cold CPU. So we waste all the cache for the lower |
| 922 | * RT task in hopes of saving some of a RT task |
| 923 | * that is just being woken and probably will have |
| 924 | * cold cache anyway. |
Gregory Haskins | 318e089 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 925 | */ |
Gregory Haskins | 17b3279 | 2008-01-25 21:08:13 +0100 | [diff] [blame] | 926 | if (unlikely(rt_task(rq->curr)) && |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 927 | (p->rt.nr_cpus_allowed > 1)) { |
Gregory Haskins | 318e089 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 928 | int cpu = find_lowest_rq(p); |
| 929 | |
| 930 | return (cpu == -1) ? task_cpu(p) : cpu; |
| 931 | } |
| 932 | |
| 933 | /* |
| 934 | * Otherwise, just let it ride on the affined RQ and the |
| 935 | * post-schedule router will push the preempted task away |
| 936 | */ |
Gregory Haskins | e7693a3 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 937 | return task_cpu(p); |
| 938 | } |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 939 | |
| 940 | static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) |
| 941 | { |
Rusty Russell | 24600ce | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 942 | cpumask_var_t mask; |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 943 | |
| 944 | if (rq->curr->rt.nr_cpus_allowed == 1) |
| 945 | return; |
| 946 | |
Rusty Russell | 24600ce | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 947 | if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 948 | return; |
| 949 | |
Rusty Russell | 24600ce | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 950 | if (p->rt.nr_cpus_allowed != 1 |
| 951 | && cpupri_find(&rq->rd->cpupri, p, mask)) |
| 952 | goto free; |
| 953 | |
| 954 | if (!cpupri_find(&rq->rd->cpupri, rq->curr, mask)) |
| 955 | goto free; |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 956 | |
| 957 | /* |
| 958 | * There appears to be other cpus that can accept |
| 959 | * current and none to run 'p', so lets reschedule |
| 960 | * to try and push current away: |
| 961 | */ |
| 962 | requeue_task_rt(rq, p, 1); |
| 963 | resched_task(rq->curr); |
Rusty Russell | 24600ce | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 964 | free: |
| 965 | free_cpumask_var(mask); |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 966 | } |
| 967 | |
Gregory Haskins | e7693a3 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 968 | #endif /* CONFIG_SMP */ |
| 969 | |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 970 | /* |
| 971 | * Preempt the current task with a newly woken task if needed: |
| 972 | */ |
Peter Zijlstra | 15afe09 | 2008-09-20 23:38:02 +0200 | [diff] [blame] | 973 | static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 974 | { |
Gregory Haskins | 45c01e8 | 2008-05-12 21:20:41 +0200 | [diff] [blame] | 975 | if (p->prio < rq->curr->prio) { |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 976 | resched_task(rq->curr); |
Gregory Haskins | 45c01e8 | 2008-05-12 21:20:41 +0200 | [diff] [blame] | 977 | return; |
| 978 | } |
| 979 | |
| 980 | #ifdef CONFIG_SMP |
| 981 | /* |
| 982 | * If: |
| 983 | * |
| 984 | * - the newly woken task is of equal priority to the current task |
| 985 | * - the newly woken task is non-migratable while current is migratable |
| 986 | * - current will be preempted on the next reschedule |
| 987 | * |
| 988 | * we should check to see if current can readily move to a different |
| 989 | * cpu. If so, we will reschedule to allow the push logic to try |
| 990 | * to move current somewhere else, making room for our non-migratable |
| 991 | * task. |
| 992 | */ |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 993 | if (p->prio == rq->curr->prio && !need_resched()) |
| 994 | check_preempt_equal_prio(rq, p); |
Gregory Haskins | 45c01e8 | 2008-05-12 21:20:41 +0200 | [diff] [blame] | 995 | #endif |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 996 | } |
| 997 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 998 | static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, |
| 999 | struct rt_rq *rt_rq) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1000 | { |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1001 | struct rt_prio_array *array = &rt_rq->active; |
| 1002 | struct sched_rt_entity *next = NULL; |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1003 | struct list_head *queue; |
| 1004 | int idx; |
| 1005 | |
| 1006 | idx = sched_find_first_bit(array->bitmap); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1007 | BUG_ON(idx >= MAX_RT_PRIO); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1008 | |
| 1009 | queue = array->queue + idx; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1010 | next = list_entry(queue->next, struct sched_rt_entity, run_list); |
Dmitry Adamushko | 326587b | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1011 | |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1012 | return next; |
| 1013 | } |
| 1014 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1015 | static struct task_struct *_pick_next_task_rt(struct rq *rq) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1016 | { |
| 1017 | struct sched_rt_entity *rt_se; |
| 1018 | struct task_struct *p; |
| 1019 | struct rt_rq *rt_rq; |
| 1020 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1021 | rt_rq = &rq->rt; |
| 1022 | |
| 1023 | if (unlikely(!rt_rq->rt_nr_running)) |
| 1024 | return NULL; |
| 1025 | |
Peter Zijlstra | 23b0fdf | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 1026 | if (rt_rq_throttled(rt_rq)) |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1027 | return NULL; |
| 1028 | |
| 1029 | do { |
| 1030 | rt_se = pick_next_rt_entity(rq, rt_rq); |
Dmitry Adamushko | 326587b | 2008-01-25 21:08:34 +0100 | [diff] [blame] | 1031 | BUG_ON(!rt_se); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1032 | rt_rq = group_rt_rq(rt_se); |
| 1033 | } while (rt_rq); |
| 1034 | |
| 1035 | p = rt_task_of(rt_se); |
| 1036 | p->se.exec_start = rq->clock; |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1037 | |
| 1038 | return p; |
| 1039 | } |
| 1040 | |
| 1041 | static struct task_struct *pick_next_task_rt(struct rq *rq) |
| 1042 | { |
| 1043 | struct task_struct *p = _pick_next_task_rt(rq); |
| 1044 | |
| 1045 | /* The running task is never eligible for pushing */ |
| 1046 | if (p) |
| 1047 | dequeue_pushable_task(rq, p); |
| 1048 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1049 | return p; |
| 1050 | } |
| 1051 | |
Ingo Molnar | 31ee529 | 2007-08-09 11:16:49 +0200 | [diff] [blame] | 1052 | static void put_prev_task_rt(struct rq *rq, struct task_struct *p) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1053 | { |
Ingo Molnar | f1e14ef | 2007-08-09 11:16:48 +0200 | [diff] [blame] | 1054 | update_curr_rt(rq); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1055 | p->se.exec_start = 0; |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1056 | |
| 1057 | /* |
| 1058 | * The previous task needs to be made eligible for pushing |
| 1059 | * if it is still active |
| 1060 | */ |
| 1061 | if (p->se.on_rq && p->rt.nr_cpus_allowed > 1) |
| 1062 | enqueue_pushable_task(rq, p); |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1063 | } |
| 1064 | |
Peter Williams | 681f3e6 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1065 | #ifdef CONFIG_SMP |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1066 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1067 | /* Only try algorithms three times */ |
| 1068 | #define RT_MAX_TRIES 3 |
| 1069 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1070 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep); |
| 1071 | |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1072 | static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) |
| 1073 | { |
| 1074 | if (!task_running(rq, p) && |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1075 | (cpu < 0 || cpumask_test_cpu(cpu, &p->cpus_allowed)) && |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1076 | (p->rt.nr_cpus_allowed > 1)) |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1077 | return 1; |
| 1078 | return 0; |
| 1079 | } |
| 1080 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1081 | /* Return the second highest RT task, NULL otherwise */ |
Ingo Molnar | 79064fb | 2008-01-25 21:08:14 +0100 | [diff] [blame] | 1082 | static struct task_struct *pick_next_highest_task_rt(struct rq *rq, int cpu) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1083 | { |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1084 | struct task_struct *next = NULL; |
| 1085 | struct sched_rt_entity *rt_se; |
| 1086 | struct rt_prio_array *array; |
| 1087 | struct rt_rq *rt_rq; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1088 | int idx; |
| 1089 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1090 | for_each_leaf_rt_rq(rt_rq, rq) { |
| 1091 | array = &rt_rq->active; |
| 1092 | idx = sched_find_first_bit(array->bitmap); |
| 1093 | next_idx: |
| 1094 | if (idx >= MAX_RT_PRIO) |
| 1095 | continue; |
| 1096 | if (next && next->prio < idx) |
| 1097 | continue; |
| 1098 | list_for_each_entry(rt_se, array->queue + idx, run_list) { |
| 1099 | struct task_struct *p = rt_task_of(rt_se); |
| 1100 | if (pick_rt_task(rq, p, cpu)) { |
| 1101 | next = p; |
| 1102 | break; |
| 1103 | } |
| 1104 | } |
| 1105 | if (!next) { |
| 1106 | idx = find_next_bit(array->bitmap, MAX_RT_PRIO, idx+1); |
| 1107 | goto next_idx; |
| 1108 | } |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1109 | } |
| 1110 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1111 | return next; |
| 1112 | } |
| 1113 | |
Rusty Russell | 0e3900e | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 1114 | static DEFINE_PER_CPU(cpumask_var_t, local_cpu_mask); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1115 | |
Gregory Haskins | 6e1254d | 2008-01-25 21:08:11 +0100 | [diff] [blame] | 1116 | static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask) |
| 1117 | { |
| 1118 | int first; |
| 1119 | |
| 1120 | /* "this_cpu" is cheaper to preempt than a remote processor */ |
| 1121 | if ((this_cpu != -1) && cpu_isset(this_cpu, *mask)) |
| 1122 | return this_cpu; |
| 1123 | |
| 1124 | first = first_cpu(*mask); |
| 1125 | if (first != NR_CPUS) |
| 1126 | return first; |
| 1127 | |
| 1128 | return -1; |
| 1129 | } |
| 1130 | |
| 1131 | static int find_lowest_rq(struct task_struct *task) |
| 1132 | { |
| 1133 | struct sched_domain *sd; |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1134 | struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask); |
Gregory Haskins | 6e1254d | 2008-01-25 21:08:11 +0100 | [diff] [blame] | 1135 | int this_cpu = smp_processor_id(); |
| 1136 | int cpu = task_cpu(task); |
| 1137 | |
Gregory Haskins | 6e0534f | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 1138 | if (task->rt.nr_cpus_allowed == 1) |
| 1139 | return -1; /* No other targets possible */ |
| 1140 | |
| 1141 | if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) |
Gregory Haskins | 06f90db | 2008-01-25 21:08:13 +0100 | [diff] [blame] | 1142 | return -1; /* No targets found */ |
| 1143 | |
| 1144 | /* |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1145 | * Only consider CPUs that are usable for migration. |
| 1146 | * I guess we might want to change cpupri_find() to ignore those |
| 1147 | * in the first place. |
| 1148 | */ |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1149 | cpumask_and(lowest_mask, lowest_mask, cpu_active_mask); |
Max Krasnyansky | e761b77 | 2008-07-15 04:43:49 -0700 | [diff] [blame] | 1150 | |
| 1151 | /* |
Gregory Haskins | 6e1254d | 2008-01-25 21:08:11 +0100 | [diff] [blame] | 1152 | * At this point we have built a mask of cpus representing the |
| 1153 | * lowest priority tasks in the system. Now we want to elect |
| 1154 | * the best one based on our affinity and topology. |
| 1155 | * |
| 1156 | * We prioritize the last cpu that the task executed on since |
| 1157 | * it is most likely cache-hot in that location. |
| 1158 | */ |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1159 | if (cpumask_test_cpu(cpu, lowest_mask)) |
Gregory Haskins | 6e1254d | 2008-01-25 21:08:11 +0100 | [diff] [blame] | 1160 | return cpu; |
| 1161 | |
| 1162 | /* |
| 1163 | * Otherwise, we consult the sched_domains span maps to figure |
| 1164 | * out which cpu is logically closest to our hot cache data. |
| 1165 | */ |
| 1166 | if (this_cpu == cpu) |
| 1167 | this_cpu = -1; /* Skip this_cpu opt if the same */ |
| 1168 | |
| 1169 | for_each_domain(cpu, sd) { |
| 1170 | if (sd->flags & SD_WAKE_AFFINE) { |
| 1171 | cpumask_t domain_mask; |
| 1172 | int best_cpu; |
| 1173 | |
Rusty Russell | 758b2cd | 2008-11-25 02:35:04 +1030 | [diff] [blame] | 1174 | cpumask_and(&domain_mask, sched_domain_span(sd), |
| 1175 | lowest_mask); |
Gregory Haskins | 6e1254d | 2008-01-25 21:08:11 +0100 | [diff] [blame] | 1176 | |
| 1177 | best_cpu = pick_optimal_cpu(this_cpu, |
| 1178 | &domain_mask); |
| 1179 | if (best_cpu != -1) |
| 1180 | return best_cpu; |
| 1181 | } |
| 1182 | } |
| 1183 | |
| 1184 | /* |
| 1185 | * And finally, if there were no matches within the domains |
| 1186 | * just give the caller *something* to work with from the compatible |
| 1187 | * locations. |
| 1188 | */ |
| 1189 | return pick_optimal_cpu(this_cpu, lowest_mask); |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1190 | } |
| 1191 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1192 | /* Will lock the rq it finds */ |
Ingo Molnar | 4df64c0 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 1193 | static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1194 | { |
| 1195 | struct rq *lowest_rq = NULL; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1196 | int tries; |
Ingo Molnar | 4df64c0 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 1197 | int cpu; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1198 | |
| 1199 | for (tries = 0; tries < RT_MAX_TRIES; tries++) { |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1200 | cpu = find_lowest_rq(task); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1201 | |
Gregory Haskins | 2de0b46 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1202 | if ((cpu == -1) || (cpu == rq->cpu)) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1203 | break; |
| 1204 | |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1205 | lowest_rq = cpu_rq(cpu); |
| 1206 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1207 | /* if the prio of this runqueue changed, try again */ |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1208 | if (double_lock_balance(rq, lowest_rq)) { |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1209 | /* |
| 1210 | * We had to unlock the run queue. In |
| 1211 | * the mean time, task could have |
| 1212 | * migrated already or had its affinity changed. |
| 1213 | * Also make sure that it wasn't scheduled on its rq. |
| 1214 | */ |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1215 | if (unlikely(task_rq(task) != rq || |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1216 | !cpumask_test_cpu(lowest_rq->cpu, |
| 1217 | &task->cpus_allowed) || |
Gregory Haskins | 07b4032 | 2008-01-25 21:08:10 +0100 | [diff] [blame] | 1218 | task_running(rq, task) || |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1219 | !task->se.on_rq)) { |
Ingo Molnar | 4df64c0 | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 1220 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1221 | spin_unlock(&lowest_rq->lock); |
| 1222 | lowest_rq = NULL; |
| 1223 | break; |
| 1224 | } |
| 1225 | } |
| 1226 | |
| 1227 | /* If this rq is still suitable use it. */ |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1228 | if (lowest_rq->rt.highest_prio.curr > task->prio) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1229 | break; |
| 1230 | |
| 1231 | /* try again */ |
Peter Zijlstra | 1b12bbc | 2008-08-11 09:30:22 +0200 | [diff] [blame] | 1232 | double_unlock_balance(rq, lowest_rq); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1233 | lowest_rq = NULL; |
| 1234 | } |
| 1235 | |
| 1236 | return lowest_rq; |
| 1237 | } |
| 1238 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1239 | static inline int has_pushable_tasks(struct rq *rq) |
| 1240 | { |
| 1241 | return !plist_head_empty(&rq->rt.pushable_tasks); |
| 1242 | } |
| 1243 | |
| 1244 | static struct task_struct *pick_next_pushable_task(struct rq *rq) |
| 1245 | { |
| 1246 | struct task_struct *p; |
| 1247 | |
| 1248 | if (!has_pushable_tasks(rq)) |
| 1249 | return NULL; |
| 1250 | |
| 1251 | p = plist_first_entry(&rq->rt.pushable_tasks, |
| 1252 | struct task_struct, pushable_tasks); |
| 1253 | |
| 1254 | BUG_ON(rq->cpu != task_cpu(p)); |
| 1255 | BUG_ON(task_current(rq, p)); |
| 1256 | BUG_ON(p->rt.nr_cpus_allowed <= 1); |
| 1257 | |
| 1258 | BUG_ON(!p->se.on_rq); |
| 1259 | BUG_ON(!rt_task(p)); |
| 1260 | |
| 1261 | return p; |
| 1262 | } |
| 1263 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1264 | /* |
| 1265 | * If the current CPU has more than one RT task, see if the non |
| 1266 | * running task can migrate over to a CPU that is running a task |
| 1267 | * of lesser priority. |
| 1268 | */ |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1269 | static int push_rt_task(struct rq *rq) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1270 | { |
| 1271 | struct task_struct *next_task; |
| 1272 | struct rq *lowest_rq; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1273 | |
Gregory Haskins | a22d7fc | 2008-01-25 21:08:12 +0100 | [diff] [blame] | 1274 | if (!rq->rt.overloaded) |
| 1275 | return 0; |
| 1276 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1277 | next_task = pick_next_pushable_task(rq); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1278 | if (!next_task) |
| 1279 | return 0; |
| 1280 | |
| 1281 | retry: |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1282 | if (unlikely(next_task == rq->curr)) { |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1283 | WARN_ON(1); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1284 | return 0; |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1285 | } |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1286 | |
| 1287 | /* |
| 1288 | * It's possible that the next_task slipped in of |
| 1289 | * higher priority than current. If that's the case |
| 1290 | * just reschedule current. |
| 1291 | */ |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1292 | if (unlikely(next_task->prio < rq->curr->prio)) { |
| 1293 | resched_task(rq->curr); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1294 | return 0; |
| 1295 | } |
| 1296 | |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1297 | /* We might release rq lock */ |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1298 | get_task_struct(next_task); |
| 1299 | |
| 1300 | /* find_lock_lowest_rq locks the rq if found */ |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1301 | lowest_rq = find_lock_lowest_rq(next_task, rq); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1302 | if (!lowest_rq) { |
| 1303 | struct task_struct *task; |
| 1304 | /* |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1305 | * find lock_lowest_rq releases rq->lock |
Gregory Haskins | 1563513 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1306 | * so it is possible that next_task has migrated. |
| 1307 | * |
| 1308 | * We need to make sure that the task is still on the same |
| 1309 | * run-queue and is also still the next task eligible for |
| 1310 | * pushing. |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1311 | */ |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1312 | task = pick_next_pushable_task(rq); |
Gregory Haskins | 1563513 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1313 | if (task_cpu(next_task) == rq->cpu && task == next_task) { |
| 1314 | /* |
| 1315 | * If we get here, the task hasnt moved at all, but |
| 1316 | * it has failed to push. We will not try again, |
| 1317 | * since the other cpus will pull from us when they |
| 1318 | * are ready. |
| 1319 | */ |
| 1320 | dequeue_pushable_task(rq, next_task); |
| 1321 | goto out; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1322 | } |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1323 | |
Gregory Haskins | 1563513 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1324 | if (!task) |
| 1325 | /* No more tasks, just exit */ |
| 1326 | goto out; |
| 1327 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1328 | /* |
Gregory Haskins | 1563513 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1329 | * Something has shifted, try again. |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1330 | */ |
Gregory Haskins | 1563513 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1331 | put_task_struct(next_task); |
| 1332 | next_task = task; |
| 1333 | goto retry; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1334 | } |
| 1335 | |
Gregory Haskins | 697f0a4 | 2008-01-25 21:08:09 +0100 | [diff] [blame] | 1336 | deactivate_task(rq, next_task, 0); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1337 | set_task_cpu(next_task, lowest_rq->cpu); |
| 1338 | activate_task(lowest_rq, next_task, 0); |
| 1339 | |
| 1340 | resched_task(lowest_rq->curr); |
| 1341 | |
Peter Zijlstra | 1b12bbc | 2008-08-11 09:30:22 +0200 | [diff] [blame] | 1342 | double_unlock_balance(rq, lowest_rq); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1343 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1344 | out: |
| 1345 | put_task_struct(next_task); |
| 1346 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1347 | return 1; |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1348 | } |
| 1349 | |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1350 | static void push_rt_tasks(struct rq *rq) |
| 1351 | { |
| 1352 | /* push_rt_task will return true if it moved an RT */ |
| 1353 | while (push_rt_task(rq)) |
| 1354 | ; |
| 1355 | } |
| 1356 | |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1357 | static int pull_rt_task(struct rq *this_rq) |
| 1358 | { |
Ingo Molnar | 80bf317 | 2008-01-25 21:08:17 +0100 | [diff] [blame] | 1359 | int this_cpu = this_rq->cpu, ret = 0, cpu; |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1360 | struct task_struct *p; |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1361 | struct rq *src_rq; |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1362 | |
Gregory Haskins | 637f508 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1363 | if (likely(!rt_overloaded(this_rq))) |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1364 | return 0; |
| 1365 | |
Rusty Russell | c6c4927 | 2008-11-25 02:35:05 +1030 | [diff] [blame] | 1366 | for_each_cpu(cpu, this_rq->rd->rto_mask) { |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1367 | if (this_cpu == cpu) |
| 1368 | continue; |
| 1369 | |
| 1370 | src_rq = cpu_rq(cpu); |
Gregory Haskins | 74ab8e4 | 2008-12-29 09:39:50 -0500 | [diff] [blame] | 1371 | |
| 1372 | /* |
| 1373 | * Don't bother taking the src_rq->lock if the next highest |
| 1374 | * task is known to be lower-priority than our current task. |
| 1375 | * This may look racy, but if this value is about to go |
| 1376 | * logically higher, the src_rq will push this task away. |
| 1377 | * And if its going logically lower, we do not care |
| 1378 | */ |
| 1379 | if (src_rq->rt.highest_prio.next >= |
| 1380 | this_rq->rt.highest_prio.curr) |
| 1381 | continue; |
| 1382 | |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1383 | /* |
| 1384 | * We can potentially drop this_rq's lock in |
| 1385 | * double_lock_balance, and another CPU could |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1386 | * alter this_rq |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1387 | */ |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1388 | double_lock_balance(this_rq, src_rq); |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1389 | |
| 1390 | /* |
| 1391 | * Are there still pullable RT tasks? |
| 1392 | */ |
Mike Galbraith | 614ee1f | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1393 | if (src_rq->rt.rt_nr_running <= 1) |
| 1394 | goto skip; |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1395 | |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1396 | p = pick_next_highest_task_rt(src_rq, this_cpu); |
| 1397 | |
| 1398 | /* |
| 1399 | * Do we have an RT task that preempts |
| 1400 | * the to-be-scheduled task? |
| 1401 | */ |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1402 | if (p && (p->prio < this_rq->rt.highest_prio.curr)) { |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1403 | WARN_ON(p == src_rq->curr); |
| 1404 | WARN_ON(!p->se.on_rq); |
| 1405 | |
| 1406 | /* |
| 1407 | * There's a chance that p is higher in priority |
| 1408 | * than what's currently running on its cpu. |
| 1409 | * This is just that p is wakeing up and hasn't |
| 1410 | * had a chance to schedule. We only pull |
| 1411 | * p if it is lower in priority than the |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1412 | * current task on the run queue |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1413 | */ |
Gregory Haskins | a872894 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1414 | if (p->prio < src_rq->curr->prio) |
Mike Galbraith | 614ee1f | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1415 | goto skip; |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1416 | |
| 1417 | ret = 1; |
| 1418 | |
| 1419 | deactivate_task(src_rq, p, 0); |
| 1420 | set_task_cpu(p, this_cpu); |
| 1421 | activate_task(this_rq, p, 0); |
| 1422 | /* |
| 1423 | * We continue with the search, just in |
| 1424 | * case there's an even higher prio task |
| 1425 | * in another runqueue. (low likelyhood |
| 1426 | * but possible) |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1427 | */ |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1428 | } |
Mike Galbraith | 614ee1f | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1429 | skip: |
Peter Zijlstra | 1b12bbc | 2008-08-11 09:30:22 +0200 | [diff] [blame] | 1430 | double_unlock_balance(this_rq, src_rq); |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1431 | } |
| 1432 | |
| 1433 | return ret; |
| 1434 | } |
| 1435 | |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1436 | static void pre_schedule_rt(struct rq *rq, struct task_struct *prev) |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1437 | { |
| 1438 | /* Try to pull RT tasks here if we lower this rq's prio */ |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1439 | if (unlikely(rt_task(prev)) && rq->rt.highest_prio.curr > prev->prio) |
Steven Rostedt | f65eda4 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1440 | pull_rt_task(rq); |
| 1441 | } |
| 1442 | |
Gregory Haskins | 967fc04 | 2008-12-29 09:39:52 -0500 | [diff] [blame] | 1443 | /* |
| 1444 | * assumes rq->lock is held |
| 1445 | */ |
| 1446 | static int needs_post_schedule_rt(struct rq *rq) |
| 1447 | { |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1448 | return has_pushable_tasks(rq); |
Gregory Haskins | 967fc04 | 2008-12-29 09:39:52 -0500 | [diff] [blame] | 1449 | } |
| 1450 | |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1451 | static void post_schedule_rt(struct rq *rq) |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1452 | { |
| 1453 | /* |
Gregory Haskins | 967fc04 | 2008-12-29 09:39:52 -0500 | [diff] [blame] | 1454 | * This is only called if needs_post_schedule_rt() indicates that |
| 1455 | * we need to push tasks away |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1456 | */ |
Gregory Haskins | 967fc04 | 2008-12-29 09:39:52 -0500 | [diff] [blame] | 1457 | spin_lock_irq(&rq->lock); |
| 1458 | push_rt_tasks(rq); |
| 1459 | spin_unlock_irq(&rq->lock); |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1460 | } |
| 1461 | |
Gregory Haskins | 8ae121a | 2008-04-23 07:13:29 -0400 | [diff] [blame] | 1462 | /* |
| 1463 | * If we are not running and we are not going to reschedule soon, we should |
| 1464 | * try to push tasks away now |
| 1465 | */ |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1466 | static void task_wake_up_rt(struct rq *rq, struct task_struct *p) |
Steven Rostedt | 4642daf | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1467 | { |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1468 | if (!task_running(rq, p) && |
Gregory Haskins | 8ae121a | 2008-04-23 07:13:29 -0400 | [diff] [blame] | 1469 | !test_tsk_need_resched(rq->curr) && |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1470 | has_pushable_tasks(rq) && |
Gregory Haskins | 777c2f3 | 2008-12-29 09:39:50 -0500 | [diff] [blame] | 1471 | p->rt.nr_cpus_allowed > 1) |
Steven Rostedt | 4642daf | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1472 | push_rt_tasks(rq); |
| 1473 | } |
| 1474 | |
Peter Williams | 4301065 | 2007-08-09 11:16:46 +0200 | [diff] [blame] | 1475 | static unsigned long |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1476 | load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, |
Peter Williams | e1d1484 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1477 | unsigned long max_load_move, |
| 1478 | struct sched_domain *sd, enum cpu_idle_type idle, |
| 1479 | int *all_pinned, int *this_best_prio) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1480 | { |
Steven Rostedt | c7a1e46 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1481 | /* don't touch RT tasks */ |
| 1482 | return 0; |
Peter Williams | e1d1484 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1483 | } |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1484 | |
Peter Williams | e1d1484 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1485 | static int |
| 1486 | move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, |
| 1487 | struct sched_domain *sd, enum cpu_idle_type idle) |
| 1488 | { |
Steven Rostedt | c7a1e46 | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1489 | /* don't touch RT tasks */ |
| 1490 | return 0; |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1491 | } |
Ingo Molnar | deeeccd | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 1492 | |
Mike Travis | cd8ba7c | 2008-03-26 14:23:49 -0700 | [diff] [blame] | 1493 | static void set_cpus_allowed_rt(struct task_struct *p, |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1494 | const struct cpumask *new_mask) |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1495 | { |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1496 | int weight = cpumask_weight(new_mask); |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1497 | |
| 1498 | BUG_ON(!rt_task(p)); |
| 1499 | |
| 1500 | /* |
| 1501 | * Update the migration status of the RQ if we have an RT task |
| 1502 | * which is running AND changing its weight value. |
| 1503 | */ |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1504 | if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) { |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1505 | struct rq *rq = task_rq(p); |
| 1506 | |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1507 | if (!task_current(rq, p)) { |
| 1508 | /* |
| 1509 | * Make sure we dequeue this task from the pushable list |
| 1510 | * before going further. It will either remain off of |
| 1511 | * the list because we are no longer pushable, or it |
| 1512 | * will be requeued. |
| 1513 | */ |
| 1514 | if (p->rt.nr_cpus_allowed > 1) |
| 1515 | dequeue_pushable_task(rq, p); |
| 1516 | |
| 1517 | /* |
| 1518 | * Requeue if our weight is changing and still > 1 |
| 1519 | */ |
| 1520 | if (weight > 1) |
| 1521 | enqueue_pushable_task(rq, p); |
| 1522 | |
| 1523 | } |
| 1524 | |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1525 | if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1526 | rq->rt.rt_nr_migratory++; |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1527 | } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1528 | BUG_ON(!rq->rt.rt_nr_migratory); |
| 1529 | rq->rt.rt_nr_migratory--; |
| 1530 | } |
| 1531 | |
Gregory Haskins | 398a153 | 2009-01-14 09:10:04 -0500 | [diff] [blame^] | 1532 | update_rt_migration(&rq->rt); |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1533 | } |
| 1534 | |
Rusty Russell | 96f874e2 | 2008-11-25 02:35:14 +1030 | [diff] [blame] | 1535 | cpumask_copy(&p->cpus_allowed, new_mask); |
Peter Zijlstra | 6f505b1 | 2008-01-25 21:08:30 +0100 | [diff] [blame] | 1536 | p->rt.nr_cpus_allowed = weight; |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1537 | } |
Ingo Molnar | deeeccd | 2008-01-25 21:08:15 +0100 | [diff] [blame] | 1538 | |
Ingo Molnar | bdd7c81 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1539 | /* Assumes rq->lock is held */ |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 1540 | static void rq_online_rt(struct rq *rq) |
Ingo Molnar | bdd7c81 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1541 | { |
| 1542 | if (rq->rt.overloaded) |
| 1543 | rt_set_overload(rq); |
Gregory Haskins | 6e0534f | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 1544 | |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 1545 | __enable_runtime(rq); |
| 1546 | |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1547 | cpupri_set(&rq->rd->cpupri, rq->cpu, rq->rt.highest_prio.curr); |
Ingo Molnar | bdd7c81 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1548 | } |
| 1549 | |
| 1550 | /* Assumes rq->lock is held */ |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 1551 | static void rq_offline_rt(struct rq *rq) |
Ingo Molnar | bdd7c81 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1552 | { |
| 1553 | if (rq->rt.overloaded) |
| 1554 | rt_clear_overload(rq); |
Gregory Haskins | 6e0534f | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 1555 | |
Peter Zijlstra | 7def2be | 2008-06-05 14:49:58 +0200 | [diff] [blame] | 1556 | __disable_runtime(rq); |
| 1557 | |
Gregory Haskins | 6e0534f | 2008-05-12 21:21:01 +0200 | [diff] [blame] | 1558 | cpupri_set(&rq->rd->cpupri, rq->cpu, CPUPRI_INVALID); |
Ingo Molnar | bdd7c81 | 2008-01-25 21:08:18 +0100 | [diff] [blame] | 1559 | } |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1560 | |
| 1561 | /* |
| 1562 | * When switch from the rt queue, we bring ourselves to a position |
| 1563 | * that we might want to pull RT tasks from other runqueues. |
| 1564 | */ |
| 1565 | static void switched_from_rt(struct rq *rq, struct task_struct *p, |
| 1566 | int running) |
| 1567 | { |
| 1568 | /* |
| 1569 | * If there are other RT tasks then we will reschedule |
| 1570 | * and the scheduling of the other RT tasks will handle |
| 1571 | * the balancing. But if we are the last RT task |
| 1572 | * we may need to handle the pulling of RT tasks |
| 1573 | * now. |
| 1574 | */ |
| 1575 | if (!rq->rt.rt_nr_running) |
| 1576 | pull_rt_task(rq); |
| 1577 | } |
Rusty Russell | 3d8cbdf | 2008-11-25 09:58:41 +1030 | [diff] [blame] | 1578 | |
| 1579 | static inline void init_sched_rt_class(void) |
| 1580 | { |
| 1581 | unsigned int i; |
| 1582 | |
| 1583 | for_each_possible_cpu(i) |
Mike Travis | 6ca09df | 2008-12-31 18:08:45 -0800 | [diff] [blame] | 1584 | alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i), |
| 1585 | GFP_KERNEL, cpu_to_node(i)); |
Rusty Russell | 3d8cbdf | 2008-11-25 09:58:41 +1030 | [diff] [blame] | 1586 | } |
Steven Rostedt | e8fa136 | 2008-01-25 21:08:05 +0100 | [diff] [blame] | 1587 | #endif /* CONFIG_SMP */ |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1588 | |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1589 | /* |
| 1590 | * When switching a task to RT, we may overload the runqueue |
| 1591 | * with RT tasks. In this case we try to push them off to |
| 1592 | * other runqueues. |
| 1593 | */ |
| 1594 | static void switched_to_rt(struct rq *rq, struct task_struct *p, |
| 1595 | int running) |
| 1596 | { |
| 1597 | int check_resched = 1; |
| 1598 | |
| 1599 | /* |
| 1600 | * If we are already running, then there's nothing |
| 1601 | * that needs to be done. But if we are not running |
| 1602 | * we may need to preempt the current running task. |
| 1603 | * If that current running task is also an RT task |
| 1604 | * then see if we can move to another run queue. |
| 1605 | */ |
| 1606 | if (!running) { |
| 1607 | #ifdef CONFIG_SMP |
| 1608 | if (rq->rt.overloaded && push_rt_task(rq) && |
| 1609 | /* Don't resched if we changed runqueues */ |
| 1610 | rq != task_rq(p)) |
| 1611 | check_resched = 0; |
| 1612 | #endif /* CONFIG_SMP */ |
| 1613 | if (check_resched && p->prio < rq->curr->prio) |
| 1614 | resched_task(rq->curr); |
| 1615 | } |
| 1616 | } |
| 1617 | |
| 1618 | /* |
| 1619 | * Priority of the task has changed. This may cause |
| 1620 | * us to initiate a push or pull. |
| 1621 | */ |
| 1622 | static void prio_changed_rt(struct rq *rq, struct task_struct *p, |
| 1623 | int oldprio, int running) |
| 1624 | { |
| 1625 | if (running) { |
| 1626 | #ifdef CONFIG_SMP |
| 1627 | /* |
| 1628 | * If our priority decreases while running, we |
| 1629 | * may need to pull tasks to this runqueue. |
| 1630 | */ |
| 1631 | if (oldprio < p->prio) |
| 1632 | pull_rt_task(rq); |
| 1633 | /* |
| 1634 | * If there's a higher priority task waiting to run |
Steven Rostedt | 6fa46fa | 2008-03-05 10:00:12 -0500 | [diff] [blame] | 1635 | * then reschedule. Note, the above pull_rt_task |
| 1636 | * can release the rq lock and p could migrate. |
| 1637 | * Only reschedule if p is still on the same runqueue. |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1638 | */ |
Gregory Haskins | e864c49 | 2008-12-29 09:39:49 -0500 | [diff] [blame] | 1639 | if (p->prio > rq->rt.highest_prio.curr && rq->curr == p) |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1640 | resched_task(p); |
| 1641 | #else |
| 1642 | /* For UP simply resched on drop of prio */ |
| 1643 | if (oldprio < p->prio) |
| 1644 | resched_task(p); |
| 1645 | #endif /* CONFIG_SMP */ |
| 1646 | } else { |
| 1647 | /* |
| 1648 | * This task is not running, but if it is |
| 1649 | * greater than the current running task |
| 1650 | * then reschedule. |
| 1651 | */ |
| 1652 | if (p->prio < rq->curr->prio) |
| 1653 | resched_task(rq->curr); |
| 1654 | } |
| 1655 | } |
| 1656 | |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1657 | static void watchdog(struct rq *rq, struct task_struct *p) |
| 1658 | { |
| 1659 | unsigned long soft, hard; |
| 1660 | |
| 1661 | if (!p->signal) |
| 1662 | return; |
| 1663 | |
| 1664 | soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur; |
| 1665 | hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max; |
| 1666 | |
| 1667 | if (soft != RLIM_INFINITY) { |
| 1668 | unsigned long next; |
| 1669 | |
| 1670 | p->rt.timeout++; |
| 1671 | next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ); |
Peter Zijlstra | 5a52dd5 | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 1672 | if (p->rt.timeout > next) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1673 | p->cputime_expires.sched_exp = p->se.sum_exec_runtime; |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1674 | } |
| 1675 | } |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1676 | |
Peter Zijlstra | 8f4d37e | 2008-01-25 21:08:29 +0100 | [diff] [blame] | 1677 | static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1678 | { |
Peter Zijlstra | 67e2be0 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 1679 | update_curr_rt(rq); |
| 1680 | |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1681 | watchdog(rq, p); |
| 1682 | |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1683 | /* |
| 1684 | * RR tasks need a special form of timeslice management. |
| 1685 | * FIFO tasks have no timeslices. |
| 1686 | */ |
| 1687 | if (p->policy != SCHED_RR) |
| 1688 | return; |
| 1689 | |
Peter Zijlstra | fa71706 | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1690 | if (--p->rt.time_slice) |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1691 | return; |
| 1692 | |
Peter Zijlstra | fa71706 | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1693 | p->rt.time_slice = DEF_TIMESLICE; |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1694 | |
Dmitry Adamushko | 98fbc79 | 2007-08-24 20:39:10 +0200 | [diff] [blame] | 1695 | /* |
| 1696 | * Requeue to the end of queue if we are not the only element |
| 1697 | * on the queue: |
| 1698 | */ |
Peter Zijlstra | fa71706 | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 1699 | if (p->rt.run_list.prev != p->rt.run_list.next) { |
Dmitry Adamushko | 7ebefa8 | 2008-07-01 23:32:15 +0200 | [diff] [blame] | 1700 | requeue_task_rt(rq, p, 0); |
Dmitry Adamushko | 98fbc79 | 2007-08-24 20:39:10 +0200 | [diff] [blame] | 1701 | set_tsk_need_resched(p); |
| 1702 | } |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1703 | } |
| 1704 | |
Srivatsa Vaddagiri | 83b699e | 2007-10-15 17:00:08 +0200 | [diff] [blame] | 1705 | static void set_curr_task_rt(struct rq *rq) |
| 1706 | { |
| 1707 | struct task_struct *p = rq->curr; |
| 1708 | |
| 1709 | p->se.exec_start = rq->clock; |
Gregory Haskins | 917b627 | 2008-12-29 09:39:53 -0500 | [diff] [blame] | 1710 | |
| 1711 | /* The running task is never eligible for pushing */ |
| 1712 | dequeue_pushable_task(rq, p); |
Srivatsa Vaddagiri | 83b699e | 2007-10-15 17:00:08 +0200 | [diff] [blame] | 1713 | } |
| 1714 | |
Harvey Harrison | 2abdad0 | 2008-04-25 10:53:13 -0700 | [diff] [blame] | 1715 | static const struct sched_class rt_sched_class = { |
Ingo Molnar | 5522d5d | 2007-10-15 17:00:12 +0200 | [diff] [blame] | 1716 | .next = &fair_sched_class, |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1717 | .enqueue_task = enqueue_task_rt, |
| 1718 | .dequeue_task = dequeue_task_rt, |
| 1719 | .yield_task = yield_task_rt, |
| 1720 | |
| 1721 | .check_preempt_curr = check_preempt_curr_rt, |
| 1722 | |
| 1723 | .pick_next_task = pick_next_task_rt, |
| 1724 | .put_prev_task = put_prev_task_rt, |
| 1725 | |
Peter Williams | 681f3e6 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1726 | #ifdef CONFIG_SMP |
Li Zefan | 4ce72a2 | 2008-10-22 15:25:26 +0800 | [diff] [blame] | 1727 | .select_task_rq = select_task_rq_rt, |
| 1728 | |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1729 | .load_balance = load_balance_rt, |
Peter Williams | e1d1484 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1730 | .move_one_task = move_one_task_rt, |
Gregory Haskins | 73fe6aa | 2008-01-25 21:08:07 +0100 | [diff] [blame] | 1731 | .set_cpus_allowed = set_cpus_allowed_rt, |
Gregory Haskins | 1f11eb6a | 2008-06-04 15:04:05 -0400 | [diff] [blame] | 1732 | .rq_online = rq_online_rt, |
| 1733 | .rq_offline = rq_offline_rt, |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1734 | .pre_schedule = pre_schedule_rt, |
Gregory Haskins | 967fc04 | 2008-12-29 09:39:52 -0500 | [diff] [blame] | 1735 | .needs_post_schedule = needs_post_schedule_rt, |
Steven Rostedt | 9a897c5 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1736 | .post_schedule = post_schedule_rt, |
| 1737 | .task_wake_up = task_wake_up_rt, |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1738 | .switched_from = switched_from_rt, |
Peter Williams | 681f3e6 | 2007-10-24 18:23:51 +0200 | [diff] [blame] | 1739 | #endif |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1740 | |
Srivatsa Vaddagiri | 83b699e | 2007-10-15 17:00:08 +0200 | [diff] [blame] | 1741 | .set_curr_task = set_curr_task_rt, |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1742 | .task_tick = task_tick_rt, |
Steven Rostedt | cb46984 | 2008-01-25 21:08:22 +0100 | [diff] [blame] | 1743 | |
| 1744 | .prio_changed = prio_changed_rt, |
| 1745 | .switched_to = switched_to_rt, |
Ingo Molnar | bb44e5d | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1746 | }; |
Peter Zijlstra | ada18de | 2008-06-19 14:22:24 +0200 | [diff] [blame] | 1747 | |
| 1748 | #ifdef CONFIG_SCHED_DEBUG |
| 1749 | extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); |
| 1750 | |
| 1751 | static void print_rt_stats(struct seq_file *m, int cpu) |
| 1752 | { |
| 1753 | struct rt_rq *rt_rq; |
| 1754 | |
| 1755 | rcu_read_lock(); |
| 1756 | for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) |
| 1757 | print_rt_rq(m, cpu, rt_rq); |
| 1758 | rcu_read_unlock(); |
| 1759 | } |
Dhaval Giani | 55e12e5 | 2008-06-24 23:39:43 +0530 | [diff] [blame] | 1760 | #endif /* CONFIG_SCHED_DEBUG */ |
Rusty Russell | 0e3900e | 2008-11-25 02:35:13 +1030 | [diff] [blame] | 1761 | |