kernel/sched/pelt.h

   1 #ifdef CONFIG_SMP
   2 #include "sched-pelt.h"
   3
   4 int __update_load_avg_blocked_se(u64 now, struct sched_entity *se);
   5 int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se);
   6 int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
   7 int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
   8 int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
   9
  10 #ifdef CONFIG_SCHED_THERMAL_PRESSURE
  11 int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
  12
  13 static inline u64 thermal_load_avg(struct rq *rq)
  14 {
  15         return READ_ONCE(rq->avg_thermal.load_avg);
  16 }
  17 #else
  18 static inline int
  19 update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
  20 {
  21         return 0;
  22 }
  23
  24 static inline u64 thermal_load_avg(struct rq *rq)
  25 {
  26         return 0;
  27 }
  28 #endif
  29
  30 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
  31 int update_irq_load_avg(struct rq *rq, u64 running);
  32 #else
  33 static inline int
  34 update_irq_load_avg(struct rq *rq, u64 running)
  35 {
  36         return 0;
  37 }
  38 #endif
  39
  40 /*
  41  * When a task is dequeued, its estimated utilization should not be update if
  42  * its util_avg has not been updated at least once.
  43  * This flag is used to synchronize util_avg updates with util_est updates.
  44  * We map this information into the LSB bit of the utilization saved at
  45  * dequeue time (i.e. util_est.dequeued).
  46  */
  47 #define UTIL_AVG_UNCHANGED 0x1
  48
  49 static inline void cfs_se_util_change(struct sched_avg *avg)
  50 {
  51         unsigned int enqueued;
  52
  53         if (!sched_feat(UTIL_EST))
  54                 return;
  55
  56         /* Avoid store if the flag has been already set */
  57         enqueued = avg->util_est.enqueued;
  58         if (!(enqueued & UTIL_AVG_UNCHANGED))
  59                 return;
  60
  61         /* Reset flag to report util_avg has been updated */
  62         enqueued &= ~UTIL_AVG_UNCHANGED;
  63         WRITE_ONCE(avg->util_est.enqueued, enqueued);
  64 }
  65
  66 /*
  67  * The clock_pelt scales the time to reflect the effective amount of
  68  * computation done during the running delta time but then sync back to
  69  * clock_task when rq is idle.
  70  *
  71  *
  72  * absolute time   | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|13|14|15|16
  73  * @ max capacity  ------******---------------******---------------
  74  * @ half capacity ------************---------************---------
  75  * clock pelt      | 1| 2|    3|    4| 7| 8| 9|   10|   11|14|15|16
  76  *
  77  */
  78 static inline void update_rq_clock_pelt(struct rq *rq, s64 delta)
  79 {
  80         if (unlikely(is_idle_task(rq->curr))) {
  81                 /* The rq is idle, we can sync to clock_task */
  82                 rq->clock_pelt  = rq_clock_task(rq);
  83                 return;
  84         }
  85
  86         /*
  87          * When a rq runs at a lower compute capacity, it will need
  88          * more time to do the same amount of work than at max
  89          * capacity. In order to be invariant, we scale the delta to
  90          * reflect how much work has been really done.
  91          * Running longer results in stealing idle time that will
  92          * disturb the load signal compared to max capacity. This
  93          * stolen idle time will be automatically reflected when the
  94          * rq will be idle and the clock will be synced with
  95          * rq_clock_task.
  96          */
  97
  98         /*
  99          * Scale the elapsed time to reflect the real amount of
 100          * computation
 101          */
 102         delta = cap_scale(delta, arch_scale_cpu_capacity(cpu_of(rq)));
 103         delta = cap_scale(delta, arch_scale_freq_capacity(cpu_of(rq)));
 104
 105         rq->clock_pelt += delta;
 106 }
 107
 108 /*
 109  * When rq becomes idle, we have to check if it has lost idle time
 110  * because it was fully busy. A rq is fully used when the /Sum util_sum
 111  * is greater or equal to:
 112  * (LOAD_AVG_MAX - 1024 + rq->cfs.avg.period_contrib) << SCHED_CAPACITY_SHIFT;
 113  * For optimization and computing rounding purpose, we don't take into account
 114  * the position in the current window (period_contrib) and we use the higher
 115  * bound of util_sum to decide.
 116  */
 117 static inline void update_idle_rq_clock_pelt(struct rq *rq)
 118 {
 119         u32 divider = ((LOAD_AVG_MAX - 1024) << SCHED_CAPACITY_SHIFT) - LOAD_AVG_MAX;
 120         u32 util_sum = rq->cfs.avg.util_sum;
 121         util_sum += rq->avg_rt.util_sum;
 122         util_sum += rq->avg_dl.util_sum;
 123
 124         /*
 125          * Reflecting stolen time makes sense only if the idle
 126          * phase would be present at max capacity. As soon as the
 127          * utilization of a rq has reached the maximum value, it is
 128          * considered as an always runnig rq without idle time to
 129          * steal. This potential idle time is considered as lost in
 130          * this case. We keep track of this lost idle time compare to
 131          * rq's clock_task.
 132          */
 133         if (util_sum >= divider)
 134                 rq->lost_idle_time += rq_clock_task(rq) - rq->clock_pelt;
 135 }
 136
 137 static inline u64 rq_clock_pelt(struct rq *rq)
 138 {
 139         lockdep_assert_held(&rq->lock);
 140         assert_clock_updated(rq);
 141
 142         return rq->clock_pelt - rq->lost_idle_time;
 143 }
 144
 145 #ifdef CONFIG_CFS_BANDWIDTH
 146 /* rq->task_clock normalized against any time this cfs_rq has spent throttled */
 147 static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
 148 {
 149         if (unlikely(cfs_rq->throttle_count))
 150                 return cfs_rq->throttled_clock_task - cfs_rq->throttled_clock_task_time;
 151
 152         return rq_clock_pelt(rq_of(cfs_rq)) - cfs_rq->throttled_clock_task_time;
 153 }
 154 #else
 155 static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq)
 156 {
 157         return rq_clock_pelt(rq_of(cfs_rq));
 158 }
 159 #endif
 160
 161 #else
 162
 163 static inline int
 164 update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 165 {
 166         return 0;
 167 }
 168
 169 static inline int
 170 update_rt_rq_load_avg(u64 now, struct rq *rq, int running)
 171 {
 172         return 0;
 173 }
 174
 175 static inline int
 176 update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
 177 {
 178         return 0;
 179 }
 180
 181 static inline int
 182 update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
 183 {
 184         return 0;
 185 }
 186
 187 static inline u64 thermal_load_avg(struct rq *rq)
 188 {
 189         return 0;
 190 }
 191
 192 static inline int
 193 update_irq_load_avg(struct rq *rq, u64 running)
 194 {
 195         return 0;
 196 }
 197
 198 static inline u64 rq_clock_pelt(struct rq *rq)
 199 {
 200         return rq_clock_task(rq);
 201 }
 202
 203 static inline void
 204 update_rq_clock_pelt(struct rq *rq, s64 delta) { }
 205
 206 static inline void
 207 update_idle_rq_clock_pelt(struct rq *rq) { }
 208
 209 #endif
 210
 211