diff options
Diffstat (limited to 'kernel/sched.c')
-rw-r--r-- | kernel/sched.c | 397 |
1 files changed, 296 insertions, 101 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index f52a8801b7a2..41541d79e3c8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c | |||
@@ -77,6 +77,7 @@ | |||
77 | #include <asm/irq_regs.h> | 77 | #include <asm/irq_regs.h> |
78 | 78 | ||
79 | #include "sched_cpupri.h" | 79 | #include "sched_cpupri.h" |
80 | #include "workqueue_sched.h" | ||
80 | 81 | ||
81 | #define CREATE_TRACE_POINTS | 82 | #define CREATE_TRACE_POINTS |
82 | #include <trace/events/sched.h> | 83 | #include <trace/events/sched.h> |
@@ -456,9 +457,10 @@ struct rq { | |||
456 | unsigned long nr_running; | 457 | unsigned long nr_running; |
457 | #define CPU_LOAD_IDX_MAX 5 | 458 | #define CPU_LOAD_IDX_MAX 5 |
458 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | 459 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; |
460 | unsigned long last_load_update_tick; | ||
459 | #ifdef CONFIG_NO_HZ | 461 | #ifdef CONFIG_NO_HZ |
460 | u64 nohz_stamp; | 462 | u64 nohz_stamp; |
461 | unsigned char in_nohz_recently; | 463 | unsigned char nohz_balance_kick; |
462 | #endif | 464 | #endif |
463 | unsigned int skip_clock_update; | 465 | unsigned int skip_clock_update; |
464 | 466 | ||
@@ -1193,6 +1195,27 @@ static void resched_cpu(int cpu) | |||
1193 | 1195 | ||
1194 | #ifdef CONFIG_NO_HZ | 1196 | #ifdef CONFIG_NO_HZ |
1195 | /* | 1197 | /* |
1198 | * In the semi idle case, use the nearest busy cpu for migrating timers | ||
1199 | * from an idle cpu. This is good for power-savings. | ||
1200 | * | ||
1201 | * We don't do similar optimization for completely idle system, as | ||
1202 | * selecting an idle cpu will add more delays to the timers than intended | ||
1203 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | ||
1204 | */ | ||
1205 | int get_nohz_timer_target(void) | ||
1206 | { | ||
1207 | int cpu = smp_processor_id(); | ||
1208 | int i; | ||
1209 | struct sched_domain *sd; | ||
1210 | |||
1211 | for_each_domain(cpu, sd) { | ||
1212 | for_each_cpu(i, sched_domain_span(sd)) | ||
1213 | if (!idle_cpu(i)) | ||
1214 | return i; | ||
1215 | } | ||
1216 | return cpu; | ||
1217 | } | ||
1218 | /* | ||
1196 | * When add_timer_on() enqueues a timer into the timer wheel of an | 1219 | * When add_timer_on() enqueues a timer into the timer wheel of an |
1197 | * idle CPU then this timer might expire before the next timer event | 1220 | * idle CPU then this timer might expire before the next timer event |
1198 | * which is scheduled to wake up that CPU. In case of a completely | 1221 | * which is scheduled to wake up that CPU. In case of a completely |
@@ -1232,16 +1255,6 @@ void wake_up_idle_cpu(int cpu) | |||
1232 | smp_send_reschedule(cpu); | 1255 | smp_send_reschedule(cpu); |
1233 | } | 1256 | } |
1234 | 1257 | ||
1235 | int nohz_ratelimit(int cpu) | ||
1236 | { | ||
1237 | struct rq *rq = cpu_rq(cpu); | ||
1238 | u64 diff = rq->clock - rq->nohz_stamp; | ||
1239 | |||
1240 | rq->nohz_stamp = rq->clock; | ||
1241 | |||
1242 | return diff < (NSEC_PER_SEC / HZ) >> 1; | ||
1243 | } | ||
1244 | |||
1245 | #endif /* CONFIG_NO_HZ */ | 1258 | #endif /* CONFIG_NO_HZ */ |
1246 | 1259 | ||
1247 | static u64 sched_avg_period(void) | 1260 | static u64 sched_avg_period(void) |
@@ -1652,7 +1665,7 @@ static void update_shares(struct sched_domain *sd) | |||
1652 | if (root_task_group_empty()) | 1665 | if (root_task_group_empty()) |
1653 | return; | 1666 | return; |
1654 | 1667 | ||
1655 | now = cpu_clock(raw_smp_processor_id()); | 1668 | now = local_clock(); |
1656 | elapsed = now - sd->last_update; | 1669 | elapsed = now - sd->last_update; |
1657 | 1670 | ||
1658 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | 1671 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { |
@@ -1805,6 +1818,7 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) | |||
1805 | static void calc_load_account_idle(struct rq *this_rq); | 1818 | static void calc_load_account_idle(struct rq *this_rq); |
1806 | static void update_sysctl(void); | 1819 | static void update_sysctl(void); |
1807 | static int get_update_sysctl_factor(void); | 1820 | static int get_update_sysctl_factor(void); |
1821 | static void update_cpu_load(struct rq *this_rq); | ||
1808 | 1822 | ||
1809 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) | 1823 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1810 | { | 1824 | { |
@@ -2267,11 +2281,55 @@ static void update_avg(u64 *avg, u64 sample) | |||
2267 | } | 2281 | } |
2268 | #endif | 2282 | #endif |
2269 | 2283 | ||
2270 | /*** | 2284 | static inline void ttwu_activate(struct task_struct *p, struct rq *rq, |
2285 | bool is_sync, bool is_migrate, bool is_local, | ||
2286 | unsigned long en_flags) | ||
2287 | { | ||
2288 | schedstat_inc(p, se.statistics.nr_wakeups); | ||
2289 | if (is_sync) | ||
2290 | schedstat_inc(p, se.statistics.nr_wakeups_sync); | ||
2291 | if (is_migrate) | ||
2292 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | ||
2293 | if (is_local) | ||
2294 | schedstat_inc(p, se.statistics.nr_wakeups_local); | ||
2295 | else | ||
2296 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | ||
2297 | |||
2298 | activate_task(rq, p, en_flags); | ||
2299 | } | ||
2300 | |||
2301 | static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, | ||
2302 | int wake_flags, bool success) | ||
2303 | { | ||
2304 | trace_sched_wakeup(p, success); | ||
2305 | check_preempt_curr(rq, p, wake_flags); | ||
2306 | |||
2307 | p->state = TASK_RUNNING; | ||
2308 | #ifdef CONFIG_SMP | ||
2309 | if (p->sched_class->task_woken) | ||
2310 | p->sched_class->task_woken(rq, p); | ||
2311 | |||
2312 | if (unlikely(rq->idle_stamp)) { | ||
2313 | u64 delta = rq->clock - rq->idle_stamp; | ||
2314 | u64 max = 2*sysctl_sched_migration_cost; | ||
2315 | |||
2316 | if (delta > max) | ||
2317 | rq->avg_idle = max; | ||
2318 | else | ||
2319 | update_avg(&rq->avg_idle, delta); | ||
2320 | rq->idle_stamp = 0; | ||
2321 | } | ||
2322 | #endif | ||
2323 | /* if a worker is waking up, notify workqueue */ | ||
2324 | if ((p->flags & PF_WQ_WORKER) && success) | ||
2325 | wq_worker_waking_up(p, cpu_of(rq)); | ||
2326 | } | ||
2327 | |||
2328 | /** | ||
2271 | * try_to_wake_up - wake up a thread | 2329 | * try_to_wake_up - wake up a thread |
2272 | * @p: the to-be-woken-up thread | 2330 | * @p: the thread to be awakened |
2273 | * @state: the mask of task states that can be woken | 2331 | * @state: the mask of task states that can be woken |
2274 | * @sync: do a synchronous wakeup? | 2332 | * @wake_flags: wake modifier flags (WF_*) |
2275 | * | 2333 | * |
2276 | * Put it on the run-queue if it's not already there. The "current" | 2334 | * Put it on the run-queue if it's not already there. The "current" |
2277 | * thread is always on the run-queue (except when the actual | 2335 | * thread is always on the run-queue (except when the actual |
@@ -2279,7 +2337,8 @@ static void update_avg(u64 *avg, u64 sample) | |||
2279 | * the simpler "current->state = TASK_RUNNING" to mark yourself | 2337 | * the simpler "current->state = TASK_RUNNING" to mark yourself |
2280 | * runnable without the overhead of this. | 2338 | * runnable without the overhead of this. |
2281 | * | 2339 | * |
2282 | * returns failure only if the task is already active. | 2340 | * Returns %true if @p was woken up, %false if it was already running |
2341 | * or @state didn't match @p's state. | ||
2283 | */ | 2342 | */ |
2284 | static int try_to_wake_up(struct task_struct *p, unsigned int state, | 2343 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2285 | int wake_flags) | 2344 | int wake_flags) |
@@ -2359,38 +2418,11 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, | |||
2359 | 2418 | ||
2360 | out_activate: | 2419 | out_activate: |
2361 | #endif /* CONFIG_SMP */ | 2420 | #endif /* CONFIG_SMP */ |
2362 | schedstat_inc(p, se.statistics.nr_wakeups); | 2421 | ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu, |
2363 | if (wake_flags & WF_SYNC) | 2422 | cpu == this_cpu, en_flags); |
2364 | schedstat_inc(p, se.statistics.nr_wakeups_sync); | ||
2365 | if (orig_cpu != cpu) | ||
2366 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | ||
2367 | if (cpu == this_cpu) | ||
2368 | schedstat_inc(p, se.statistics.nr_wakeups_local); | ||
2369 | else | ||
2370 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | ||
2371 | activate_task(rq, p, en_flags); | ||
2372 | success = 1; | 2423 | success = 1; |
2373 | |||
2374 | out_running: | 2424 | out_running: |
2375 | trace_sched_wakeup(p, success); | 2425 | ttwu_post_activation(p, rq, wake_flags, success); |
2376 | check_preempt_curr(rq, p, wake_flags); | ||
2377 | |||
2378 | p->state = TASK_RUNNING; | ||
2379 | #ifdef CONFIG_SMP | ||
2380 | if (p->sched_class->task_woken) | ||
2381 | p->sched_class->task_woken(rq, p); | ||
2382 | |||
2383 | if (unlikely(rq->idle_stamp)) { | ||
2384 | u64 delta = rq->clock - rq->idle_stamp; | ||
2385 | u64 max = 2*sysctl_sched_migration_cost; | ||
2386 | |||
2387 | if (delta > max) | ||
2388 | rq->avg_idle = max; | ||
2389 | else | ||
2390 | update_avg(&rq->avg_idle, delta); | ||
2391 | rq->idle_stamp = 0; | ||
2392 | } | ||
2393 | #endif | ||
2394 | out: | 2426 | out: |
2395 | task_rq_unlock(rq, &flags); | 2427 | task_rq_unlock(rq, &flags); |
2396 | put_cpu(); | 2428 | put_cpu(); |
@@ -2399,6 +2431,37 @@ out: | |||
2399 | } | 2431 | } |
2400 | 2432 | ||
2401 | /** | 2433 | /** |
2434 | * try_to_wake_up_local - try to wake up a local task with rq lock held | ||
2435 | * @p: the thread to be awakened | ||
2436 | * | ||
2437 | * Put @p on the run-queue if it's not alredy there. The caller must | ||
2438 | * ensure that this_rq() is locked, @p is bound to this_rq() and not | ||
2439 | * the current task. this_rq() stays locked over invocation. | ||
2440 | */ | ||
2441 | static void try_to_wake_up_local(struct task_struct *p) | ||
2442 | { | ||
2443 | struct rq *rq = task_rq(p); | ||
2444 | bool success = false; | ||
2445 | |||
2446 | BUG_ON(rq != this_rq()); | ||
2447 | BUG_ON(p == current); | ||
2448 | lockdep_assert_held(&rq->lock); | ||
2449 | |||
2450 | if (!(p->state & TASK_NORMAL)) | ||
2451 | return; | ||
2452 | |||
2453 | if (!p->se.on_rq) { | ||
2454 | if (likely(!task_running(rq, p))) { | ||
2455 | schedstat_inc(rq, ttwu_count); | ||
2456 | schedstat_inc(rq, ttwu_local); | ||
2457 | } | ||
2458 | ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP); | ||
2459 | success = true; | ||
2460 | } | ||
2461 | ttwu_post_activation(p, rq, 0, success); | ||
2462 | } | ||
2463 | |||
2464 | /** | ||
2402 | * wake_up_process - Wake up a specific process | 2465 | * wake_up_process - Wake up a specific process |
2403 | * @p: The process to be woken up. | 2466 | * @p: The process to be woken up. |
2404 | * | 2467 | * |
@@ -3012,23 +3075,102 @@ static void calc_load_account_active(struct rq *this_rq) | |||
3012 | } | 3075 | } |
3013 | 3076 | ||
3014 | /* | 3077 | /* |
3078 | * The exact cpuload at various idx values, calculated at every tick would be | ||
3079 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | ||
3080 | * | ||
3081 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | ||
3082 | * on nth tick when cpu may be busy, then we have: | ||
3083 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | ||
3084 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | ||
3085 | * | ||
3086 | * decay_load_missed() below does efficient calculation of | ||
3087 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | ||
3088 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | ||
3089 | * | ||
3090 | * The calculation is approximated on a 128 point scale. | ||
3091 | * degrade_zero_ticks is the number of ticks after which load at any | ||
3092 | * particular idx is approximated to be zero. | ||
3093 | * degrade_factor is a precomputed table, a row for each load idx. | ||
3094 | * Each column corresponds to degradation factor for a power of two ticks, | ||
3095 | * based on 128 point scale. | ||
3096 | * Example: | ||
3097 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | ||
3098 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | ||
3099 | * | ||
3100 | * With this power of 2 load factors, we can degrade the load n times | ||
3101 | * by looking at 1 bits in n and doing as many mult/shift instead of | ||
3102 | * n mult/shifts needed by the exact degradation. | ||
3103 | */ | ||
3104 | #define DEGRADE_SHIFT 7 | ||
3105 | static const unsigned char | ||
3106 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | ||
3107 | static const unsigned char | ||
3108 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | ||
3109 | {0, 0, 0, 0, 0, 0, 0, 0}, | ||
3110 | {64, 32, 8, 0, 0, 0, 0, 0}, | ||
3111 | {96, 72, 40, 12, 1, 0, 0}, | ||
3112 | {112, 98, 75, 43, 15, 1, 0}, | ||
3113 | {120, 112, 98, 76, 45, 16, 2} }; | ||
3114 | |||
3115 | /* | ||
3116 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | ||
3117 | * would be when CPU is idle and so we just decay the old load without | ||
3118 | * adding any new load. | ||
3119 | */ | ||
3120 | static unsigned long | ||
3121 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | ||
3122 | { | ||
3123 | int j = 0; | ||
3124 | |||
3125 | if (!missed_updates) | ||
3126 | return load; | ||
3127 | |||
3128 | if (missed_updates >= degrade_zero_ticks[idx]) | ||
3129 | return 0; | ||
3130 | |||
3131 | if (idx == 1) | ||
3132 | return load >> missed_updates; | ||
3133 | |||
3134 | while (missed_updates) { | ||
3135 | if (missed_updates % 2) | ||
3136 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | ||
3137 | |||
3138 | missed_updates >>= 1; | ||
3139 | j++; | ||
3140 | } | ||
3141 | return load; | ||
3142 | } | ||
3143 | |||
3144 | /* | ||
3015 | * Update rq->cpu_load[] statistics. This function is usually called every | 3145 | * Update rq->cpu_load[] statistics. This function is usually called every |
3016 | * scheduler tick (TICK_NSEC). | 3146 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
3147 | * every tick. We fix it up based on jiffies. | ||
3017 | */ | 3148 | */ |
3018 | static void update_cpu_load(struct rq *this_rq) | 3149 | static void update_cpu_load(struct rq *this_rq) |
3019 | { | 3150 | { |
3020 | unsigned long this_load = this_rq->load.weight; | 3151 | unsigned long this_load = this_rq->load.weight; |
3152 | unsigned long curr_jiffies = jiffies; | ||
3153 | unsigned long pending_updates; | ||
3021 | int i, scale; | 3154 | int i, scale; |
3022 | 3155 | ||
3023 | this_rq->nr_load_updates++; | 3156 | this_rq->nr_load_updates++; |
3024 | 3157 | ||
3158 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ | ||
3159 | if (curr_jiffies == this_rq->last_load_update_tick) | ||
3160 | return; | ||
3161 | |||
3162 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | ||
3163 | this_rq->last_load_update_tick = curr_jiffies; | ||
3164 | |||
3025 | /* Update our load: */ | 3165 | /* Update our load: */ |
3026 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | 3166 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
3167 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | ||
3027 | unsigned long old_load, new_load; | 3168 | unsigned long old_load, new_load; |
3028 | 3169 | ||
3029 | /* scale is effectively 1 << i now, and >> i divides by scale */ | 3170 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
3030 | 3171 | ||
3031 | old_load = this_rq->cpu_load[i]; | 3172 | old_load = this_rq->cpu_load[i]; |
3173 | old_load = decay_load_missed(old_load, pending_updates - 1, i); | ||
3032 | new_load = this_load; | 3174 | new_load = this_load; |
3033 | /* | 3175 | /* |
3034 | * Round up the averaging division if load is increasing. This | 3176 | * Round up the averaging division if load is increasing. This |
@@ -3036,9 +3178,15 @@ static void update_cpu_load(struct rq *this_rq) | |||
3036 | * example. | 3178 | * example. |
3037 | */ | 3179 | */ |
3038 | if (new_load > old_load) | 3180 | if (new_load > old_load) |
3039 | new_load += scale-1; | 3181 | new_load += scale - 1; |
3040 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; | 3182 | |
3183 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | ||
3041 | } | 3184 | } |
3185 | } | ||
3186 | |||
3187 | static void update_cpu_load_active(struct rq *this_rq) | ||
3188 | { | ||
3189 | update_cpu_load(this_rq); | ||
3042 | 3190 | ||
3043 | calc_load_account_active(this_rq); | 3191 | calc_load_account_active(this_rq); |
3044 | } | 3192 | } |
@@ -3426,7 +3574,7 @@ void scheduler_tick(void) | |||
3426 | 3574 | ||
3427 | raw_spin_lock(&rq->lock); | 3575 | raw_spin_lock(&rq->lock); |
3428 | update_rq_clock(rq); | 3576 | update_rq_clock(rq); |
3429 | update_cpu_load(rq); | 3577 | update_cpu_load_active(rq); |
3430 | curr->sched_class->task_tick(rq, curr, 0); | 3578 | curr->sched_class->task_tick(rq, curr, 0); |
3431 | raw_spin_unlock(&rq->lock); | 3579 | raw_spin_unlock(&rq->lock); |
3432 | 3580 | ||
@@ -3598,7 +3746,6 @@ need_resched: | |||
3598 | rq = cpu_rq(cpu); | 3746 | rq = cpu_rq(cpu); |
3599 | rcu_note_context_switch(cpu); | 3747 | rcu_note_context_switch(cpu); |
3600 | prev = rq->curr; | 3748 | prev = rq->curr; |
3601 | switch_count = &prev->nivcsw; | ||
3602 | 3749 | ||
3603 | release_kernel_lock(prev); | 3750 | release_kernel_lock(prev); |
3604 | need_resched_nonpreemptible: | 3751 | need_resched_nonpreemptible: |
@@ -3611,11 +3758,26 @@ need_resched_nonpreemptible: | |||
3611 | raw_spin_lock_irq(&rq->lock); | 3758 | raw_spin_lock_irq(&rq->lock); |
3612 | clear_tsk_need_resched(prev); | 3759 | clear_tsk_need_resched(prev); |
3613 | 3760 | ||
3761 | switch_count = &prev->nivcsw; | ||
3614 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { | 3762 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
3615 | if (unlikely(signal_pending_state(prev->state, prev))) | 3763 | if (unlikely(signal_pending_state(prev->state, prev))) { |
3616 | prev->state = TASK_RUNNING; | 3764 | prev->state = TASK_RUNNING; |
3617 | else | 3765 | } else { |
3766 | /* | ||
3767 | * If a worker is going to sleep, notify and | ||
3768 | * ask workqueue whether it wants to wake up a | ||
3769 | * task to maintain concurrency. If so, wake | ||
3770 | * up the task. | ||
3771 | */ | ||
3772 | if (prev->flags & PF_WQ_WORKER) { | ||
3773 | struct task_struct *to_wakeup; | ||
3774 | |||
3775 | to_wakeup = wq_worker_sleeping(prev, cpu); | ||
3776 | if (to_wakeup) | ||
3777 | try_to_wake_up_local(to_wakeup); | ||
3778 | } | ||
3618 | deactivate_task(rq, prev, DEQUEUE_SLEEP); | 3779 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
3780 | } | ||
3619 | switch_count = &prev->nvcsw; | 3781 | switch_count = &prev->nvcsw; |
3620 | } | 3782 | } |
3621 | 3783 | ||
@@ -3637,8 +3799,10 @@ need_resched_nonpreemptible: | |||
3637 | 3799 | ||
3638 | context_switch(rq, prev, next); /* unlocks the rq */ | 3800 | context_switch(rq, prev, next); /* unlocks the rq */ |
3639 | /* | 3801 | /* |
3640 | * the context switch might have flipped the stack from under | 3802 | * The context switch have flipped the stack from under us |
3641 | * us, hence refresh the local variables. | 3803 | * and restored the local variables which were saved when |
3804 | * this task called schedule() in the past. prev == current | ||
3805 | * is still correct, but it can be moved to another cpu/rq. | ||
3642 | */ | 3806 | */ |
3643 | cpu = smp_processor_id(); | 3807 | cpu = smp_processor_id(); |
3644 | rq = cpu_rq(cpu); | 3808 | rq = cpu_rq(cpu); |
@@ -3647,11 +3811,8 @@ need_resched_nonpreemptible: | |||
3647 | 3811 | ||
3648 | post_schedule(rq); | 3812 | post_schedule(rq); |
3649 | 3813 | ||
3650 | if (unlikely(reacquire_kernel_lock(current) < 0)) { | 3814 | if (unlikely(reacquire_kernel_lock(prev))) |
3651 | prev = rq->curr; | ||
3652 | switch_count = &prev->nivcsw; | ||
3653 | goto need_resched_nonpreemptible; | 3815 | goto need_resched_nonpreemptible; |
3654 | } | ||
3655 | 3816 | ||
3656 | preempt_enable_no_resched(); | 3817 | preempt_enable_no_resched(); |
3657 | if (need_resched()) | 3818 | if (need_resched()) |
@@ -3726,7 +3887,7 @@ int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |||
3726 | * off of preempt_enable. Kernel preemptions off return from interrupt | 3887 | * off of preempt_enable. Kernel preemptions off return from interrupt |
3727 | * occur there and call schedule directly. | 3888 | * occur there and call schedule directly. |
3728 | */ | 3889 | */ |
3729 | asmlinkage void __sched preempt_schedule(void) | 3890 | asmlinkage void __sched notrace preempt_schedule(void) |
3730 | { | 3891 | { |
3731 | struct thread_info *ti = current_thread_info(); | 3892 | struct thread_info *ti = current_thread_info(); |
3732 | 3893 | ||
@@ -3738,9 +3899,9 @@ asmlinkage void __sched preempt_schedule(void) | |||
3738 | return; | 3899 | return; |
3739 | 3900 | ||
3740 | do { | 3901 | do { |
3741 | add_preempt_count(PREEMPT_ACTIVE); | 3902 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
3742 | schedule(); | 3903 | schedule(); |
3743 | sub_preempt_count(PREEMPT_ACTIVE); | 3904 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
3744 | 3905 | ||
3745 | /* | 3906 | /* |
3746 | * Check again in case we missed a preemption opportunity | 3907 | * Check again in case we missed a preemption opportunity |
@@ -4441,12 +4602,8 @@ recheck: | |||
4441 | */ | 4602 | */ |
4442 | if (user && !capable(CAP_SYS_NICE)) { | 4603 | if (user && !capable(CAP_SYS_NICE)) { |
4443 | if (rt_policy(policy)) { | 4604 | if (rt_policy(policy)) { |
4444 | unsigned long rlim_rtprio; | 4605 | unsigned long rlim_rtprio = |
4445 | 4606 | task_rlimit(p, RLIMIT_RTPRIO); | |
4446 | if (!lock_task_sighand(p, &flags)) | ||
4447 | return -ESRCH; | ||
4448 | rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); | ||
4449 | unlock_task_sighand(p, &flags); | ||
4450 | 4607 | ||
4451 | /* can't set/change the rt policy */ | 4608 | /* can't set/change the rt policy */ |
4452 | if (policy != p->policy && !rlim_rtprio) | 4609 | if (policy != p->policy && !rlim_rtprio) |
@@ -5816,20 +5973,49 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |||
5816 | */ | 5973 | */ |
5817 | static struct notifier_block __cpuinitdata migration_notifier = { | 5974 | static struct notifier_block __cpuinitdata migration_notifier = { |
5818 | .notifier_call = migration_call, | 5975 | .notifier_call = migration_call, |
5819 | .priority = 10 | 5976 | .priority = CPU_PRI_MIGRATION, |
5820 | }; | 5977 | }; |
5821 | 5978 | ||
5979 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, | ||
5980 | unsigned long action, void *hcpu) | ||
5981 | { | ||
5982 | switch (action & ~CPU_TASKS_FROZEN) { | ||
5983 | case CPU_ONLINE: | ||
5984 | case CPU_DOWN_FAILED: | ||
5985 | set_cpu_active((long)hcpu, true); | ||
5986 | return NOTIFY_OK; | ||
5987 | default: | ||
5988 | return NOTIFY_DONE; | ||
5989 | } | ||
5990 | } | ||
5991 | |||
5992 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | ||
5993 | unsigned long action, void *hcpu) | ||
5994 | { | ||
5995 | switch (action & ~CPU_TASKS_FROZEN) { | ||
5996 | case CPU_DOWN_PREPARE: | ||
5997 | set_cpu_active((long)hcpu, false); | ||
5998 | return NOTIFY_OK; | ||
5999 | default: | ||
6000 | return NOTIFY_DONE; | ||
6001 | } | ||
6002 | } | ||
6003 | |||
5822 | static int __init migration_init(void) | 6004 | static int __init migration_init(void) |
5823 | { | 6005 | { |
5824 | void *cpu = (void *)(long)smp_processor_id(); | 6006 | void *cpu = (void *)(long)smp_processor_id(); |
5825 | int err; | 6007 | int err; |
5826 | 6008 | ||
5827 | /* Start one for the boot CPU: */ | 6009 | /* Initialize migration for the boot CPU */ |
5828 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); | 6010 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5829 | BUG_ON(err == NOTIFY_BAD); | 6011 | BUG_ON(err == NOTIFY_BAD); |
5830 | migration_call(&migration_notifier, CPU_ONLINE, cpu); | 6012 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5831 | register_cpu_notifier(&migration_notifier); | 6013 | register_cpu_notifier(&migration_notifier); |
5832 | 6014 | ||
6015 | /* Register cpu active notifiers */ | ||
6016 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | ||
6017 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | ||
6018 | |||
5833 | return 0; | 6019 | return 0; |
5834 | } | 6020 | } |
5835 | early_initcall(migration_init); | 6021 | early_initcall(migration_init); |
@@ -6064,23 +6250,18 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd) | |||
6064 | free_rootdomain(old_rd); | 6250 | free_rootdomain(old_rd); |
6065 | } | 6251 | } |
6066 | 6252 | ||
6067 | static int init_rootdomain(struct root_domain *rd, bool bootmem) | 6253 | static int init_rootdomain(struct root_domain *rd) |
6068 | { | 6254 | { |
6069 | gfp_t gfp = GFP_KERNEL; | ||
6070 | |||
6071 | memset(rd, 0, sizeof(*rd)); | 6255 | memset(rd, 0, sizeof(*rd)); |
6072 | 6256 | ||
6073 | if (bootmem) | 6257 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
6074 | gfp = GFP_NOWAIT; | ||
6075 | |||
6076 | if (!alloc_cpumask_var(&rd->span, gfp)) | ||
6077 | goto out; | 6258 | goto out; |
6078 | if (!alloc_cpumask_var(&rd->online, gfp)) | 6259 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
6079 | goto free_span; | 6260 | goto free_span; |
6080 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) | 6261 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
6081 | goto free_online; | 6262 | goto free_online; |
6082 | 6263 | ||
6083 | if (cpupri_init(&rd->cpupri, bootmem) != 0) | 6264 | if (cpupri_init(&rd->cpupri) != 0) |
6084 | goto free_rto_mask; | 6265 | goto free_rto_mask; |
6085 | return 0; | 6266 | return 0; |
6086 | 6267 | ||
@@ -6096,7 +6277,7 @@ out: | |||
6096 | 6277 | ||
6097 | static void init_defrootdomain(void) | 6278 | static void init_defrootdomain(void) |
6098 | { | 6279 | { |
6099 | init_rootdomain(&def_root_domain, true); | 6280 | init_rootdomain(&def_root_domain); |
6100 | 6281 | ||
6101 | atomic_set(&def_root_domain.refcount, 1); | 6282 | atomic_set(&def_root_domain.refcount, 1); |
6102 | } | 6283 | } |
@@ -6109,7 +6290,7 @@ static struct root_domain *alloc_rootdomain(void) | |||
6109 | if (!rd) | 6290 | if (!rd) |
6110 | return NULL; | 6291 | return NULL; |
6111 | 6292 | ||
6112 | if (init_rootdomain(rd, false) != 0) { | 6293 | if (init_rootdomain(rd) != 0) { |
6113 | kfree(rd); | 6294 | kfree(rd); |
6114 | return NULL; | 6295 | return NULL; |
6115 | } | 6296 | } |
@@ -7288,29 +7469,35 @@ int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) | |||
7288 | } | 7469 | } |
7289 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | 7470 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
7290 | 7471 | ||
7291 | #ifndef CONFIG_CPUSETS | ||
7292 | /* | 7472 | /* |
7293 | * Add online and remove offline CPUs from the scheduler domains. | 7473 | * Update cpusets according to cpu_active mask. If cpusets are |
7294 | * When cpusets are enabled they take over this function. | 7474 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper |
7475 | * around partition_sched_domains(). | ||
7295 | */ | 7476 | */ |
7296 | static int update_sched_domains(struct notifier_block *nfb, | 7477 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7297 | unsigned long action, void *hcpu) | 7478 | void *hcpu) |
7298 | { | 7479 | { |
7299 | switch (action) { | 7480 | switch (action & ~CPU_TASKS_FROZEN) { |
7300 | case CPU_ONLINE: | 7481 | case CPU_ONLINE: |
7301 | case CPU_ONLINE_FROZEN: | ||
7302 | case CPU_DOWN_PREPARE: | ||
7303 | case CPU_DOWN_PREPARE_FROZEN: | ||
7304 | case CPU_DOWN_FAILED: | 7482 | case CPU_DOWN_FAILED: |
7305 | case CPU_DOWN_FAILED_FROZEN: | 7483 | cpuset_update_active_cpus(); |
7306 | partition_sched_domains(1, NULL, NULL); | ||
7307 | return NOTIFY_OK; | 7484 | return NOTIFY_OK; |
7485 | default: | ||
7486 | return NOTIFY_DONE; | ||
7487 | } | ||
7488 | } | ||
7308 | 7489 | ||
7490 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, | ||
7491 | void *hcpu) | ||
7492 | { | ||
7493 | switch (action & ~CPU_TASKS_FROZEN) { | ||
7494 | case CPU_DOWN_PREPARE: | ||
7495 | cpuset_update_active_cpus(); | ||
7496 | return NOTIFY_OK; | ||
7309 | default: | 7497 | default: |
7310 | return NOTIFY_DONE; | 7498 | return NOTIFY_DONE; |
7311 | } | 7499 | } |
7312 | } | 7500 | } |
7313 | #endif | ||
7314 | 7501 | ||
7315 | static int update_runtime(struct notifier_block *nfb, | 7502 | static int update_runtime(struct notifier_block *nfb, |
7316 | unsigned long action, void *hcpu) | 7503 | unsigned long action, void *hcpu) |
@@ -7356,10 +7543,8 @@ void __init sched_init_smp(void) | |||
7356 | mutex_unlock(&sched_domains_mutex); | 7543 | mutex_unlock(&sched_domains_mutex); |
7357 | put_online_cpus(); | 7544 | put_online_cpus(); |
7358 | 7545 | ||
7359 | #ifndef CONFIG_CPUSETS | 7546 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
7360 | /* XXX: Theoretical race here - CPU may be hotplugged now */ | 7547 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); |
7361 | hotcpu_notifier(update_sched_domains, 0); | ||
7362 | #endif | ||
7363 | 7548 | ||
7364 | /* RT runtime code needs to handle some hotplug events */ | 7549 | /* RT runtime code needs to handle some hotplug events */ |
7365 | hotcpu_notifier(update_runtime, 0); | 7550 | hotcpu_notifier(update_runtime, 0); |
@@ -7604,6 +7789,9 @@ void __init sched_init(void) | |||
7604 | 7789 | ||
7605 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) | 7790 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7606 | rq->cpu_load[j] = 0; | 7791 | rq->cpu_load[j] = 0; |
7792 | |||
7793 | rq->last_load_update_tick = jiffies; | ||
7794 | |||
7607 | #ifdef CONFIG_SMP | 7795 | #ifdef CONFIG_SMP |
7608 | rq->sd = NULL; | 7796 | rq->sd = NULL; |
7609 | rq->rd = NULL; | 7797 | rq->rd = NULL; |
@@ -7617,6 +7805,10 @@ void __init sched_init(void) | |||
7617 | rq->idle_stamp = 0; | 7805 | rq->idle_stamp = 0; |
7618 | rq->avg_idle = 2*sysctl_sched_migration_cost; | 7806 | rq->avg_idle = 2*sysctl_sched_migration_cost; |
7619 | rq_attach_root(rq, &def_root_domain); | 7807 | rq_attach_root(rq, &def_root_domain); |
7808 | #ifdef CONFIG_NO_HZ | ||
7809 | rq->nohz_balance_kick = 0; | ||
7810 | init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i)); | ||
7811 | #endif | ||
7620 | #endif | 7812 | #endif |
7621 | init_rq_hrtick(rq); | 7813 | init_rq_hrtick(rq); |
7622 | atomic_set(&rq->nr_iowait, 0); | 7814 | atomic_set(&rq->nr_iowait, 0); |
@@ -7661,8 +7853,11 @@ void __init sched_init(void) | |||
7661 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); | 7853 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
7662 | #ifdef CONFIG_SMP | 7854 | #ifdef CONFIG_SMP |
7663 | #ifdef CONFIG_NO_HZ | 7855 | #ifdef CONFIG_NO_HZ |
7664 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); | 7856 | zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
7665 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); | 7857 | alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); |
7858 | atomic_set(&nohz.load_balancer, nr_cpu_ids); | ||
7859 | atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); | ||
7860 | atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); | ||
7666 | #endif | 7861 | #endif |
7667 | /* May be allocated at isolcpus cmdline parse time */ | 7862 | /* May be allocated at isolcpus cmdline parse time */ |
7668 | if (cpu_isolated_map == NULL) | 7863 | if (cpu_isolated_map == NULL) |