diff options
Diffstat (limited to 'kernel/sched.c')
-rw-r--r-- | kernel/sched.c | 155 |
1 files changed, 1 insertions, 154 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 5f102e6c7a4c..a4ca632c477c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c | |||
@@ -3006,23 +3006,6 @@ static inline void idle_balance(int cpu, struct rq *rq) | |||
3006 | } | 3006 | } |
3007 | #endif | 3007 | #endif |
3008 | 3008 | ||
3009 | static inline void wake_priority_sleeper(struct rq *rq) | ||
3010 | { | ||
3011 | #ifdef CONFIG_SCHED_SMT | ||
3012 | if (!rq->nr_running) | ||
3013 | return; | ||
3014 | |||
3015 | spin_lock(&rq->lock); | ||
3016 | /* | ||
3017 | * If an SMT sibling task has been put to sleep for priority | ||
3018 | * reasons reschedule the idle task to see if it can now run. | ||
3019 | */ | ||
3020 | if (rq->nr_running) | ||
3021 | resched_task(rq->idle); | ||
3022 | spin_unlock(&rq->lock); | ||
3023 | #endif | ||
3024 | } | ||
3025 | |||
3026 | DEFINE_PER_CPU(struct kernel_stat, kstat); | 3009 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3027 | 3010 | ||
3028 | EXPORT_PER_CPU_SYMBOL(kstat); | 3011 | EXPORT_PER_CPU_SYMBOL(kstat); |
@@ -3239,10 +3222,7 @@ void scheduler_tick(void) | |||
3239 | 3222 | ||
3240 | update_cpu_clock(p, rq, now); | 3223 | update_cpu_clock(p, rq, now); |
3241 | 3224 | ||
3242 | if (p == rq->idle) | 3225 | if (p != rq->idle) |
3243 | /* Task on the idle queue */ | ||
3244 | wake_priority_sleeper(rq); | ||
3245 | else | ||
3246 | task_running_tick(rq, p); | 3226 | task_running_tick(rq, p); |
3247 | #ifdef CONFIG_SMP | 3227 | #ifdef CONFIG_SMP |
3248 | update_load(rq); | 3228 | update_load(rq); |
@@ -3251,136 +3231,6 @@ void scheduler_tick(void) | |||
3251 | #endif | 3231 | #endif |
3252 | } | 3232 | } |
3253 | 3233 | ||
3254 | #ifdef CONFIG_SCHED_SMT | ||
3255 | static inline void wakeup_busy_runqueue(struct rq *rq) | ||
3256 | { | ||
3257 | /* If an SMT runqueue is sleeping due to priority reasons wake it up */ | ||
3258 | if (rq->curr == rq->idle && rq->nr_running) | ||
3259 | resched_task(rq->idle); | ||
3260 | } | ||
3261 | |||
3262 | /* | ||
3263 | * Called with interrupt disabled and this_rq's runqueue locked. | ||
3264 | */ | ||
3265 | static void wake_sleeping_dependent(int this_cpu) | ||
3266 | { | ||
3267 | struct sched_domain *tmp, *sd = NULL; | ||
3268 | int i; | ||
3269 | |||
3270 | for_each_domain(this_cpu, tmp) { | ||
3271 | if (tmp->flags & SD_SHARE_CPUPOWER) { | ||
3272 | sd = tmp; | ||
3273 | break; | ||
3274 | } | ||
3275 | } | ||
3276 | |||
3277 | if (!sd) | ||
3278 | return; | ||
3279 | |||
3280 | for_each_cpu_mask(i, sd->span) { | ||
3281 | struct rq *smt_rq = cpu_rq(i); | ||
3282 | |||
3283 | if (i == this_cpu) | ||
3284 | continue; | ||
3285 | if (unlikely(!spin_trylock(&smt_rq->lock))) | ||
3286 | continue; | ||
3287 | |||
3288 | wakeup_busy_runqueue(smt_rq); | ||
3289 | spin_unlock(&smt_rq->lock); | ||
3290 | } | ||
3291 | } | ||
3292 | |||
3293 | /* | ||
3294 | * number of 'lost' timeslices this task wont be able to fully | ||
3295 | * utilize, if another task runs on a sibling. This models the | ||
3296 | * slowdown effect of other tasks running on siblings: | ||
3297 | */ | ||
3298 | static inline unsigned long | ||
3299 | smt_slice(struct task_struct *p, struct sched_domain *sd) | ||
3300 | { | ||
3301 | return p->time_slice * (100 - sd->per_cpu_gain) / 100; | ||
3302 | } | ||
3303 | |||
3304 | /* | ||
3305 | * To minimise lock contention and not have to drop this_rq's runlock we only | ||
3306 | * trylock the sibling runqueues and bypass those runqueues if we fail to | ||
3307 | * acquire their lock. As we only trylock the normal locking order does not | ||
3308 | * need to be obeyed. | ||
3309 | */ | ||
3310 | static int | ||
3311 | dependent_sleeper(int this_cpu, struct rq *this_rq, struct task_struct *p) | ||
3312 | { | ||
3313 | struct sched_domain *tmp, *sd = NULL; | ||
3314 | int ret = 0, i; | ||
3315 | |||
3316 | /* kernel/rt threads do not participate in dependent sleeping */ | ||
3317 | if (!p->mm || rt_task(p)) | ||
3318 | return 0; | ||
3319 | |||
3320 | for_each_domain(this_cpu, tmp) { | ||
3321 | if (tmp->flags & SD_SHARE_CPUPOWER) { | ||
3322 | sd = tmp; | ||
3323 | break; | ||
3324 | } | ||
3325 | } | ||
3326 | |||
3327 | if (!sd) | ||
3328 | return 0; | ||
3329 | |||
3330 | for_each_cpu_mask(i, sd->span) { | ||
3331 | struct task_struct *smt_curr; | ||
3332 | struct rq *smt_rq; | ||
3333 | |||
3334 | if (i == this_cpu) | ||
3335 | continue; | ||
3336 | |||
3337 | smt_rq = cpu_rq(i); | ||
3338 | if (unlikely(!spin_trylock(&smt_rq->lock))) | ||
3339 | continue; | ||
3340 | |||
3341 | smt_curr = smt_rq->curr; | ||
3342 | |||
3343 | if (!smt_curr->mm) | ||
3344 | goto unlock; | ||
3345 | |||
3346 | /* | ||
3347 | * If a user task with lower static priority than the | ||
3348 | * running task on the SMT sibling is trying to schedule, | ||
3349 | * delay it till there is proportionately less timeslice | ||
3350 | * left of the sibling task to prevent a lower priority | ||
3351 | * task from using an unfair proportion of the | ||
3352 | * physical cpu's resources. -ck | ||
3353 | */ | ||
3354 | if (rt_task(smt_curr)) { | ||
3355 | /* | ||
3356 | * With real time tasks we run non-rt tasks only | ||
3357 | * per_cpu_gain% of the time. | ||
3358 | */ | ||
3359 | if ((jiffies % DEF_TIMESLICE) > | ||
3360 | (sd->per_cpu_gain * DEF_TIMESLICE / 100)) | ||
3361 | ret = 1; | ||
3362 | } else { | ||
3363 | if (smt_curr->static_prio < p->static_prio && | ||
3364 | !TASK_PREEMPTS_CURR(p, smt_rq) && | ||
3365 | smt_slice(smt_curr, sd) > task_timeslice(p)) | ||
3366 | ret = 1; | ||
3367 | } | ||
3368 | unlock: | ||
3369 | spin_unlock(&smt_rq->lock); | ||
3370 | } | ||
3371 | return ret; | ||
3372 | } | ||
3373 | #else | ||
3374 | static inline void wake_sleeping_dependent(int this_cpu) | ||
3375 | { | ||
3376 | } | ||
3377 | static inline int | ||
3378 | dependent_sleeper(int this_cpu, struct rq *this_rq, struct task_struct *p) | ||
3379 | { | ||
3380 | return 0; | ||
3381 | } | ||
3382 | #endif | ||
3383 | |||
3384 | #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT) | 3234 | #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT) |
3385 | 3235 | ||
3386 | void fastcall add_preempt_count(int val) | 3236 | void fastcall add_preempt_count(int val) |
@@ -3507,7 +3357,6 @@ need_resched_nonpreemptible: | |||
3507 | if (!rq->nr_running) { | 3357 | if (!rq->nr_running) { |
3508 | next = rq->idle; | 3358 | next = rq->idle; |
3509 | rq->expired_timestamp = 0; | 3359 | rq->expired_timestamp = 0; |
3510 | wake_sleeping_dependent(cpu); | ||
3511 | goto switch_tasks; | 3360 | goto switch_tasks; |
3512 | } | 3361 | } |
3513 | } | 3362 | } |
@@ -3547,8 +3396,6 @@ need_resched_nonpreemptible: | |||
3547 | } | 3396 | } |
3548 | } | 3397 | } |
3549 | next->sleep_type = SLEEP_NORMAL; | 3398 | next->sleep_type = SLEEP_NORMAL; |
3550 | if (rq->nr_running == 1 && dependent_sleeper(cpu, rq, next)) | ||
3551 | next = rq->idle; | ||
3552 | switch_tasks: | 3399 | switch_tasks: |
3553 | if (next == rq->idle) | 3400 | if (next == rq->idle) |
3554 | schedstat_inc(rq, sched_goidle); | 3401 | schedstat_inc(rq, sched_goidle); |