LCOV - code coverage report
Current view: top level - kernel/sched - stats.h (source / functions) Hit Total Coverage
Test: Real Lines: 33 33 100.0 %
Date: 2020-10-17 15:46:16 Functions: 0 4 0.0 %
Legend: Neither, QEMU, Real, Both Branches: 0 0 -

           Branch data     Line data    Source code
       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : 
       3                 :            : #ifdef CONFIG_SCHEDSTATS
       4                 :            : 
       5                 :            : /*
       6                 :            :  * Expects runqueue lock to be held for atomicity of update
       7                 :            :  */
       8                 :            : static inline void
       9                 :            : rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
      10                 :            : {
      11                 :          3 :         if (rq) {
      12                 :          3 :                 rq->rq_sched_info.run_delay += delta;
      13                 :          3 :                 rq->rq_sched_info.pcount++;
      14                 :            :         }
      15                 :            : }
      16                 :            : 
      17                 :            : /*
      18                 :            :  * Expects runqueue lock to be held for atomicity of update
      19                 :            :  */
      20                 :            : static inline void
      21                 :            : rq_sched_info_depart(struct rq *rq, unsigned long long delta)
      22                 :            : {
      23                 :          3 :         if (rq)
      24                 :          3 :                 rq->rq_cpu_time += delta;
      25                 :            : }
      26                 :            : 
      27                 :            : static inline void
      28                 :            : rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
      29                 :            : {
      30                 :          3 :         if (rq)
      31                 :          3 :                 rq->rq_sched_info.run_delay += delta;
      32                 :            : }
      33                 :            : #define   schedstat_enabled()           static_branch_unlikely(&sched_schedstats)
      34                 :            : #define __schedstat_inc(var)            do { var++; } while (0)
      35                 :            : #define   schedstat_inc(var)            do { if (schedstat_enabled()) { var++; } } while (0)
      36                 :            : #define __schedstat_add(var, amt)       do { var += (amt); } while (0)
      37                 :            : #define   schedstat_add(var, amt)       do { if (schedstat_enabled()) { var += (amt); } } while (0)
      38                 :            : #define __schedstat_set(var, val)       do { var = (val); } while (0)
      39                 :            : #define   schedstat_set(var, val)       do { if (schedstat_enabled()) { var = (val); } } while (0)
      40                 :            : #define   schedstat_val(var)            (var)
      41                 :            : #define   schedstat_val_or_zero(var)    ((schedstat_enabled()) ? (var) : 0)
      42                 :            : 
      43                 :            : #else /* !CONFIG_SCHEDSTATS: */
      44                 :            : static inline void rq_sched_info_arrive  (struct rq *rq, unsigned long long delta) { }
      45                 :            : static inline void rq_sched_info_dequeued(struct rq *rq, unsigned long long delta) { }
      46                 :            : static inline void rq_sched_info_depart  (struct rq *rq, unsigned long long delta) { }
      47                 :            : # define   schedstat_enabled()          0
      48                 :            : # define __schedstat_inc(var)           do { } while (0)
      49                 :            : # define   schedstat_inc(var)           do { } while (0)
      50                 :            : # define __schedstat_add(var, amt)      do { } while (0)
      51                 :            : # define   schedstat_add(var, amt)      do { } while (0)
      52                 :            : # define __schedstat_set(var, val)      do { } while (0)
      53                 :            : # define   schedstat_set(var, val)      do { } while (0)
      54                 :            : # define   schedstat_val(var)           0
      55                 :            : # define   schedstat_val_or_zero(var)   0
      56                 :            : #endif /* CONFIG_SCHEDSTATS */
      57                 :            : 
      58                 :            : #ifdef CONFIG_PSI
      59                 :            : /*
      60                 :            :  * PSI tracks state that persists across sleeps, such as iowaits and
      61                 :            :  * memory stalls. As a result, it has to distinguish between sleeps,
      62                 :            :  * where a task's runnable state changes, and requeues, where a task
      63                 :            :  * and its state are being moved between CPUs and runqueues.
      64                 :            :  */
      65                 :            : static inline void psi_enqueue(struct task_struct *p, bool wakeup)
      66                 :            : {
      67                 :            :         int clear = 0, set = TSK_RUNNING;
      68                 :            : 
      69                 :            :         if (static_branch_likely(&psi_disabled))
      70                 :            :                 return;
      71                 :            : 
      72                 :            :         if (!wakeup || p->sched_psi_wake_requeue) {
      73                 :            :                 if (p->flags & PF_MEMSTALL)
      74                 :            :                         set |= TSK_MEMSTALL;
      75                 :            :                 if (p->sched_psi_wake_requeue)
      76                 :            :                         p->sched_psi_wake_requeue = 0;
      77                 :            :         } else {
      78                 :            :                 if (p->in_iowait)
      79                 :            :                         clear |= TSK_IOWAIT;
      80                 :            :         }
      81                 :            : 
      82                 :            :         psi_task_change(p, clear, set);
      83                 :            : }
      84                 :            : 
      85                 :            : static inline void psi_dequeue(struct task_struct *p, bool sleep)
      86                 :            : {
      87                 :            :         int clear = TSK_RUNNING, set = 0;
      88                 :            : 
      89                 :            :         if (static_branch_likely(&psi_disabled))
      90                 :            :                 return;
      91                 :            : 
      92                 :            :         if (!sleep) {
      93                 :            :                 if (p->flags & PF_MEMSTALL)
      94                 :            :                         clear |= TSK_MEMSTALL;
      95                 :            :         } else {
      96                 :            :                 if (p->in_iowait)
      97                 :            :                         set |= TSK_IOWAIT;
      98                 :            :         }
      99                 :            : 
     100                 :            :         psi_task_change(p, clear, set);
     101                 :            : }
     102                 :            : 
     103                 :            : static inline void psi_ttwu_dequeue(struct task_struct *p)
     104                 :            : {
     105                 :            :         if (static_branch_likely(&psi_disabled))
     106                 :            :                 return;
     107                 :            :         /*
     108                 :            :          * Is the task being migrated during a wakeup? Make sure to
     109                 :            :          * deregister its sleep-persistent psi states from the old
     110                 :            :          * queue, and let psi_enqueue() know it has to requeue.
     111                 :            :          */
     112                 :            :         if (unlikely(p->in_iowait || (p->flags & PF_MEMSTALL))) {
     113                 :            :                 struct rq_flags rf;
     114                 :            :                 struct rq *rq;
     115                 :            :                 int clear = 0;
     116                 :            : 
     117                 :            :                 if (p->in_iowait)
     118                 :            :                         clear |= TSK_IOWAIT;
     119                 :            :                 if (p->flags & PF_MEMSTALL)
     120                 :            :                         clear |= TSK_MEMSTALL;
     121                 :            : 
     122                 :            :                 rq = __task_rq_lock(p, &rf);
     123                 :            :                 psi_task_change(p, clear, 0);
     124                 :            :                 p->sched_psi_wake_requeue = 1;
     125                 :            :                 __task_rq_unlock(rq, &rf);
     126                 :            :         }
     127                 :            : }
     128                 :            : 
     129                 :            : static inline void psi_task_tick(struct rq *rq)
     130                 :            : {
     131                 :            :         if (static_branch_likely(&psi_disabled))
     132                 :            :                 return;
     133                 :            : 
     134                 :            :         if (unlikely(rq->curr->flags & PF_MEMSTALL))
     135                 :            :                 psi_memstall_tick(rq->curr, cpu_of(rq));
     136                 :            : }
     137                 :            : #else /* CONFIG_PSI */
     138                 :            : static inline void psi_enqueue(struct task_struct *p, bool wakeup) {}
     139                 :            : static inline void psi_dequeue(struct task_struct *p, bool sleep) {}
     140                 :            : static inline void psi_ttwu_dequeue(struct task_struct *p) {}
     141                 :            : static inline void psi_task_tick(struct rq *rq) {}
     142                 :            : #endif /* CONFIG_PSI */
     143                 :            : 
     144                 :            : #ifdef CONFIG_SCHED_INFO
     145                 :            : static inline void sched_info_reset_dequeued(struct task_struct *t)
     146                 :            : {
     147                 :          3 :         t->sched_info.last_queued = 0;
     148                 :            : }
     149                 :            : 
     150                 :            : /*
     151                 :            :  * We are interested in knowing how long it was from the *first* time a
     152                 :            :  * task was queued to the time that it finally hit a CPU, we call this routine
     153                 :            :  * from dequeue_task() to account for possible rq->clock skew across CPUs. The
     154                 :            :  * delta taken on each CPU would annul the skew.
     155                 :            :  */
     156                 :          3 : static inline void sched_info_dequeued(struct rq *rq, struct task_struct *t)
     157                 :            : {
     158                 :            :         unsigned long long now = rq_clock(rq), delta = 0;
     159                 :            : 
     160                 :            :         if (sched_info_on()) {
     161                 :          3 :                 if (t->sched_info.last_queued)
     162                 :          3 :                         delta = now - t->sched_info.last_queued;
     163                 :            :         }
     164                 :            :         sched_info_reset_dequeued(t);
     165                 :          3 :         t->sched_info.run_delay += delta;
     166                 :            : 
     167                 :            :         rq_sched_info_dequeued(rq, delta);
     168                 :          3 : }
     169                 :            : 
     170                 :            : /*
     171                 :            :  * Called when a task finally hits the CPU.  We can now calculate how
     172                 :            :  * long it was waiting to run.  We also note when it began so that we
     173                 :            :  * can keep stats on how long its timeslice is.
     174                 :            :  */
     175                 :          3 : static void sched_info_arrive(struct rq *rq, struct task_struct *t)
     176                 :            : {
     177                 :            :         unsigned long long now = rq_clock(rq), delta = 0;
     178                 :            : 
     179                 :          3 :         if (t->sched_info.last_queued)
     180                 :          3 :                 delta = now - t->sched_info.last_queued;
     181                 :            :         sched_info_reset_dequeued(t);
     182                 :          3 :         t->sched_info.run_delay += delta;
     183                 :          3 :         t->sched_info.last_arrival = now;
     184                 :          3 :         t->sched_info.pcount++;
     185                 :            : 
     186                 :            :         rq_sched_info_arrive(rq, delta);
     187                 :          3 : }
     188                 :            : 
     189                 :            : /*
     190                 :            :  * This function is only called from enqueue_task(), but also only updates
     191                 :            :  * the timestamp if it is already not set.  It's assumed that
     192                 :            :  * sched_info_dequeued() will clear that stamp when appropriate.
     193                 :            :  */
     194                 :            : static inline void sched_info_queued(struct rq *rq, struct task_struct *t)
     195                 :            : {
     196                 :            :         if (sched_info_on()) {
     197                 :          3 :                 if (!t->sched_info.last_queued)
     198                 :          3 :                         t->sched_info.last_queued = rq_clock(rq);
     199                 :            :         }
     200                 :            : }
     201                 :            : 
     202                 :            : /*
     203                 :            :  * Called when a process ceases being the active-running process involuntarily
     204                 :            :  * due, typically, to expiring its time slice (this may also be called when
     205                 :            :  * switching to the idle task).  Now we can calculate how long we ran.
     206                 :            :  * Also, if the process is still in the TASK_RUNNING state, call
     207                 :            :  * sched_info_queued() to mark that it has now again started waiting on
     208                 :            :  * the runqueue.
     209                 :            :  */
     210                 :          3 : static inline void sched_info_depart(struct rq *rq, struct task_struct *t)
     211                 :            : {
     212                 :          3 :         unsigned long long delta = rq_clock(rq) - t->sched_info.last_arrival;
     213                 :            : 
     214                 :            :         rq_sched_info_depart(rq, delta);
     215                 :            : 
     216                 :          3 :         if (t->state == TASK_RUNNING)
     217                 :            :                 sched_info_queued(rq, t);
     218                 :          3 : }
     219                 :            : 
     220                 :            : /*
     221                 :            :  * Called when tasks are switched involuntarily due, typically, to expiring
     222                 :            :  * their time slice.  (This may also be called when switching to or from
     223                 :            :  * the idle task.)  We are only called when prev != next.
     224                 :            :  */
     225                 :            : static inline void
     226                 :          3 : __sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
     227                 :            : {
     228                 :            :         /*
     229                 :            :          * prev now departs the CPU.  It's not interesting to record
     230                 :            :          * stats about how efficient we were at scheduling the idle
     231                 :            :          * process, however.
     232                 :            :          */
     233                 :          3 :         if (prev != rq->idle)
     234                 :          3 :                 sched_info_depart(rq, prev);
     235                 :            : 
     236                 :          3 :         if (next != rq->idle)
     237                 :          3 :                 sched_info_arrive(rq, next);
     238                 :          3 : }
     239                 :            : 
     240                 :            : static inline void
     241                 :            : sched_info_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next)
     242                 :            : {
     243                 :            :         if (sched_info_on())
     244                 :          3 :                 __sched_info_switch(rq, prev, next);
     245                 :            : }
     246                 :            : 
     247                 :            : #else /* !CONFIG_SCHED_INFO: */
     248                 :            : # define sched_info_queued(rq, t)       do { } while (0)
     249                 :            : # define sched_info_reset_dequeued(t)   do { } while (0)
     250                 :            : # define sched_info_dequeued(rq, t)     do { } while (0)
     251                 :            : # define sched_info_depart(rq, t)       do { } while (0)
     252                 :            : # define sched_info_arrive(rq, next)    do { } while (0)
     253                 :            : # define sched_info_switch(rq, t, next) do { } while (0)
     254                 :            : #endif /* CONFIG_SCHED_INFO */
    

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