sched: Implement group scheduler statistics in one struct

Put all statistic fields of sched_entity in one struct, sched_statistics,
and embed it into sched_entity.

This change allows to memset the sched_statistics to 0 when needed (for
instance when forking), avoiding bugs of non initialized fields.

Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 106 insertions, 163 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4b1753f7e48e..8cc863d66477 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1127,36 +1127,8 @@ struct load_weight {
         unsigned long weight, inv_weight;
 };
 
-/*
- * CFS stats for a schedulable entity (task, task-group etc)
- *
- * Current field usage histogram:
- *
- *     4 se->block_start
- *     4 se->run_node
- *     4 se->sleep_start
- *     6 se->load.weight
- */
-struct sched_entity {
-        struct load_weight      load;           /* for load-balancing */
-        struct rb_node          run_node;
-        struct list_head        group_node;
-        unsigned int            on_rq;
-
-        u64                     exec_start;
-        u64                     sum_exec_runtime;
-        u64                     vruntime;
-        u64                     prev_sum_exec_runtime;
-
-        u64                     last_wakeup;
-        u64                     avg_overlap;
-
-        u64                     nr_migrations;
-
-        u64                     start_runtime;
-        u64                     avg_wakeup;
-
 #ifdef CONFIG_SCHEDSTATS
+struct sched_statistics {
         u64                     wait_start;
         u64                     wait_max;
         u64                     wait_count;
@@ -1188,6 +1160,30 @@ struct sched_entity {
         u64                     nr_wakeups_affine_attempts;
         u64                     nr_wakeups_passive;
         u64                     nr_wakeups_idle;
+};
+#endif
+
+struct sched_entity {
+        struct load_weight      load;           /* for load-balancing */
+        struct rb_node          run_node;
+        struct list_head        group_node;
+        unsigned int            on_rq;
+
+        u64                     exec_start;
+        u64                     sum_exec_runtime;
+        u64                     vruntime;
+        u64                     prev_sum_exec_runtime;
+
+        u64                     last_wakeup;
+        u64                     avg_overlap;
+
+        u64                     nr_migrations;
+
+        u64                     start_runtime;
+        u64                     avg_wakeup;
+
+#ifdef CONFIG_SCHEDSTATS
+        struct sched_statistics statistics;
 #endif
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched.c b/kernel/sched.c
index 2c1db81f80eb..a4aa071f08f3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2437,15 +2437,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 
 out_activate:
 #endif /* CONFIG_SMP */
-        schedstat_inc(p, se.nr_wakeups);
+        schedstat_inc(p, se.statistics.nr_wakeups);
         if (wake_flags & WF_SYNC)
-                schedstat_inc(p, se.nr_wakeups_sync);
+                schedstat_inc(p, se.statistics.nr_wakeups_sync);
         if (orig_cpu != cpu)
-                schedstat_inc(p, se.nr_wakeups_migrate);
+                schedstat_inc(p, se.statistics.nr_wakeups_migrate);
         if (cpu == this_cpu)
-                schedstat_inc(p, se.nr_wakeups_local);
+                schedstat_inc(p, se.statistics.nr_wakeups_local);
         else
-                schedstat_inc(p, se.nr_wakeups_remote);
+                schedstat_inc(p, se.statistics.nr_wakeups_remote);
         activate_task(rq, p, 1);
         success = 1;
 
@@ -2532,36 +2532,7 @@ static void __sched_fork(struct task_struct *p)
         p->se.avg_wakeup                = sysctl_sched_wakeup_granularity;
 
 #ifdef CONFIG_SCHEDSTATS
-        p->se.wait_start                        = 0;
-        p->se.wait_max                          = 0;
-        p->se.wait_count                        = 0;
-        p->se.wait_sum                          = 0;
-
-        p->se.sleep_start                       = 0;
-        p->se.sleep_max                         = 0;
-        p->se.sum_sleep_runtime                 = 0;
-
-        p->se.block_start                       = 0;
-        p->se.block_max                         = 0;
-        p->se.exec_max                          = 0;
-        p->se.slice_max                         = 0;
-
-        p->se.nr_migrations_cold                = 0;
-        p->se.nr_failed_migrations_affine       = 0;
-        p->se.nr_failed_migrations_running      = 0;
-        p->se.nr_failed_migrations_hot          = 0;
-        p->se.nr_forced_migrations              = 0;
-
-        p->se.nr_wakeups                        = 0;
-        p->se.nr_wakeups_sync                   = 0;
-        p->se.nr_wakeups_migrate                = 0;
-        p->se.nr_wakeups_local                  = 0;
-        p->se.nr_wakeups_remote                 = 0;
-        p->se.nr_wakeups_affine                 = 0;
-        p->se.nr_wakeups_affine_attempts        = 0;
-        p->se.nr_wakeups_passive                = 0;
-        p->se.nr_wakeups_idle                   = 0;
-
+        memset(&p->se.statistics, 0, sizeof(p->se.statistics));
 #endif
 
         INIT_LIST_HEAD(&p->rt.run_list);
@@ -7910,9 +7881,9 @@ void normalize_rt_tasks(void)
 
                 p->se.exec_start                = 0;
 #ifdef CONFIG_SCHEDSTATS
-                p->se.wait_start                = 0;
-                p->se.sleep_start               = 0;
-                p->se.block_start               = 0;
+                p->se.statistics.wait_start     = 0;
+                p->se.statistics.sleep_start    = 0;
+                p->se.statistics.block_start    = 0;
 #endif
 
                 if (!rt_task(p)) {
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 67f95aada4b9..ad9df4422763 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -70,16 +70,16 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu,
         PN(se->vruntime);
         PN(se->sum_exec_runtime);
 #ifdef CONFIG_SCHEDSTATS
-        PN(se->wait_start);
-        PN(se->sleep_start);
-        PN(se->block_start);
-        PN(se->sleep_max);
-        PN(se->block_max);
-        PN(se->exec_max);
-        PN(se->slice_max);
-        PN(se->wait_max);
-        PN(se->wait_sum);
-        P(se->wait_count);
+        PN(se->statistics.wait_start);
+        PN(se->statistics.sleep_start);
+        PN(se->statistics.block_start);
+        PN(se->statistics.sleep_max);
+        PN(se->statistics.block_max);
+        PN(se->statistics.exec_max);
+        PN(se->statistics.slice_max);
+        PN(se->statistics.wait_max);
+        PN(se->statistics.wait_sum);
+        P(se->statistics.wait_count);
 #endif
         P(se->load.weight);
 #undef PN
@@ -104,7 +104,7 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
         SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
                 SPLIT_NS(p->se.vruntime),
                 SPLIT_NS(p->se.sum_exec_runtime),
-                SPLIT_NS(p->se.sum_sleep_runtime));
+                SPLIT_NS(p->se.statistics.sum_sleep_runtime));
 #else
         SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
                 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
@@ -413,34 +413,34 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
         nr_switches = p->nvcsw + p->nivcsw;
 
 #ifdef CONFIG_SCHEDSTATS
-        PN(se.wait_start);
-        PN(se.sleep_start);
-        PN(se.block_start);
-        PN(se.sleep_max);
-        PN(se.block_max);
-        PN(se.exec_max);
-        PN(se.slice_max);
-        PN(se.wait_max);
-        PN(se.wait_sum);
-        P(se.wait_count);
-        PN(se.iowait_sum);
-        P(se.iowait_count);
+        PN(se.statistics.wait_start);
+        PN(se.statistics.sleep_start);
+        PN(se.statistics.block_start);
+        PN(se.statistics.sleep_max);
+        PN(se.statistics.block_max);
+        PN(se.statistics.exec_max);
+        PN(se.statistics.slice_max);
+        PN(se.statistics.wait_max);
+        PN(se.statistics.wait_sum);
+        P(se.statistics.wait_count);
+        PN(se.statistics.iowait_sum);
+        P(se.statistics.iowait_count);
         P(sched_info.bkl_count);
         P(se.nr_migrations);
-        P(se.nr_migrations_cold);
-        P(se.nr_failed_migrations_affine);
-        P(se.nr_failed_migrations_running);
-        P(se.nr_failed_migrations_hot);
-        P(se.nr_forced_migrations);
-        P(se.nr_wakeups);
-        P(se.nr_wakeups_sync);
-        P(se.nr_wakeups_migrate);
-        P(se.nr_wakeups_local);
-        P(se.nr_wakeups_remote);
-        P(se.nr_wakeups_affine);
-        P(se.nr_wakeups_affine_attempts);
-        P(se.nr_wakeups_passive);
-        P(se.nr_wakeups_idle);
+        P(se.statistics.nr_migrations_cold);
+        P(se.statistics.nr_failed_migrations_affine);
+        P(se.statistics.nr_failed_migrations_running);
+        P(se.statistics.nr_failed_migrations_hot);
+        P(se.statistics.nr_forced_migrations);
+        P(se.statistics.nr_wakeups);
+        P(se.statistics.nr_wakeups_sync);
+        P(se.statistics.nr_wakeups_migrate);
+        P(se.statistics.nr_wakeups_local);
+        P(se.statistics.nr_wakeups_remote);
+        P(se.statistics.nr_wakeups_affine);
+        P(se.statistics.nr_wakeups_affine_attempts);
+        P(se.statistics.nr_wakeups_passive);
+        P(se.statistics.nr_wakeups_idle);
 
         {
                 u64 avg_atom, avg_per_cpu;
@@ -491,32 +491,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 void proc_sched_set_task(struct task_struct *p)
 {
 #ifdef CONFIG_SCHEDSTATS
-        p->se.wait_max                          = 0;
-        p->se.wait_sum                          = 0;
-        p->se.wait_count                        = 0;
-        p->se.iowait_sum                        = 0;
-        p->se.iowait_count                      = 0;
-        p->se.sleep_max                         = 0;
-        p->se.sum_sleep_runtime                 = 0;
-        p->se.block_max                         = 0;
-        p->se.exec_max                          = 0;
-        p->se.slice_max                         = 0;
-        p->se.nr_migrations                     = 0;
-        p->se.nr_migrations_cold                = 0;
-        p->se.nr_failed_migrations_affine       = 0;
-        p->se.nr_failed_migrations_running      = 0;
-        p->se.nr_failed_migrations_hot          = 0;
-        p->se.nr_forced_migrations              = 0;
-        p->se.nr_wakeups                        = 0;
-        p->se.nr_wakeups_sync                   = 0;
-        p->se.nr_wakeups_migrate                = 0;
-        p->se.nr_wakeups_local                  = 0;
-        p->se.nr_wakeups_remote                 = 0;
-        p->se.nr_wakeups_affine                 = 0;
-        p->se.nr_wakeups_affine_attempts        = 0;
-        p->se.nr_wakeups_passive                = 0;
-        p->se.nr_wakeups_idle                   = 0;
-        p->sched_info.bkl_count                 = 0;
+        memset(&p->se.statistics, 0, sizeof(p->se.statistics));
 #endif
         p->se.sum_exec_runtime                  = 0;
         p->se.prev_sum_exec_runtime             = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 3e1fd96c6cf9..8ad164bbdac1 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -505,7 +505,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
 {
         unsigned long delta_exec_weighted;
 
-        schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
+        schedstat_set(curr->statistics.exec_max,
+                      max((u64)delta_exec, curr->statistics.exec_max));
 
         curr->sum_exec_runtime += delta_exec;
         schedstat_add(cfs_rq, exec_clock, delta_exec);
@@ -548,7 +549,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
 static inline void
 update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
+        schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
 }
 
 /*
@@ -567,18 +568,18 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static void
 update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        schedstat_set(se->wait_max, max(se->wait_max,
-                        rq_of(cfs_rq)->clock - se->wait_start));
-        schedstat_set(se->wait_count, se->wait_count + 1);
-        schedstat_set(se->wait_sum, se->wait_sum +
-                        rq_of(cfs_rq)->clock - se->wait_start);
+        schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start));
+        schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+        schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start);
 #ifdef CONFIG_SCHEDSTATS
         if (entity_is_task(se)) {
                 trace_sched_stat_wait(task_of(se),
-                        rq_of(cfs_rq)->clock - se->wait_start);
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start);
         }
 #endif
-        schedstat_set(se->wait_start, 0);
+        schedstat_set(se->statistics.wait_start, 0);
 }
 
 static inline void
@@ -657,39 +658,39 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
         if (entity_is_task(se))
                 tsk = task_of(se);
 
-        if (se->sleep_start) {
-                u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
+        if (se->statistics.sleep_start) {
+                u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;
 
                 if ((s64)delta < 0)
                         delta = 0;
 
-                if (unlikely(delta > se->sleep_max))
-                        se->sleep_max = delta;
+                if (unlikely(delta > se->statistics.sleep_max))
+                        se->statistics.sleep_max = delta;
 
-                se->sleep_start = 0;
-                se->sum_sleep_runtime += delta;
+                se->statistics.sleep_start = 0;
+                se->statistics.sum_sleep_runtime += delta;
 
                 if (tsk) {
                         account_scheduler_latency(tsk, delta >> 10, 1);
                         trace_sched_stat_sleep(tsk, delta);
                 }
         }
-        if (se->block_start) {
-                u64 delta = rq_of(cfs_rq)->clock - se->block_start;
+        if (se->statistics.block_start) {
+                u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;
 
                 if ((s64)delta < 0)
                         delta = 0;
 
-                if (unlikely(delta > se->block_max))
-                        se->block_max = delta;
+                if (unlikely(delta > se->statistics.block_max))
+                        se->statistics.block_max = delta;
 
-                se->block_start = 0;
-                se->sum_sleep_runtime += delta;
+                se->statistics.block_start = 0;
+                se->statistics.sum_sleep_runtime += delta;
 
                 if (tsk) {
                         if (tsk->in_iowait) {
-                                se->iowait_sum += delta;
-                                se->iowait_count++;
+                                se->statistics.iowait_sum += delta;
+                                se->statistics.iowait_count++;
                                 trace_sched_stat_iowait(tsk, delta);
                         }
 
@@ -826,9 +827,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
                         struct task_struct *tsk = task_of(se);
 
                         if (tsk->state & TASK_INTERRUPTIBLE)
-                                se->sleep_start = rq_of(cfs_rq)->clock;
+                                se->statistics.sleep_start = rq_of(cfs_rq)->clock;
                         if (tsk->state & TASK_UNINTERRUPTIBLE)
-                                se->block_start = rq_of(cfs_rq)->clock;
+                                se->statistics.block_start = rq_of(cfs_rq)->clock;
                 }
 #endif
         }
@@ -912,7 +913,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
          * when there are only lesser-weight tasks around):
          */
         if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
-                se->slice_max = max(se->slice_max,
+                se->statistics.slice_max = max(se->statistics.slice_max,
                         se->sum_exec_runtime - se->prev_sum_exec_runtime);
         }
 #endif
@@ -1306,7 +1307,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
         if (sync && balanced)
                 return 1;
 
-        schedstat_inc(p, se.nr_wakeups_affine_attempts);
+        schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
         tl_per_task = cpu_avg_load_per_task(this_cpu);
 
         if (balanced ||
@@ -1318,7 +1319,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
                  * there is no bad imbalance.
                  */
                 schedstat_inc(sd, ttwu_move_affine);
-                schedstat_inc(p, se.nr_wakeups_affine);
+                schedstat_inc(p, se.statistics.nr_wakeups_affine);
 
                 return 1;
         }
@@ -1844,13 +1845,13 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
          * 3) are cache-hot on their current CPU.
          */
         if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
-                schedstat_inc(p, se.nr_failed_migrations_affine);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
                 return 0;
         }
         *all_pinned = 0;
 
         if (task_running(rq, p)) {
-                schedstat_inc(p, se.nr_failed_migrations_running);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_running);
                 return 0;
         }
 
@@ -1866,14 +1867,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
 #ifdef CONFIG_SCHEDSTATS
                 if (tsk_cache_hot) {
                         schedstat_inc(sd, lb_hot_gained[idle]);
-                        schedstat_inc(p, se.nr_forced_migrations);
+                        schedstat_inc(p, se.statistics.nr_forced_migrations);
                 }
 #endif
                 return 1;
         }
 
         if (tsk_cache_hot) {
-                schedstat_inc(p, se.nr_failed_migrations_hot);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
                 return 0;
         }
         return 1;
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index c4fb42a66cab..0335e87f5204 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -613,7 +613,7 @@ static void update_curr_rt(struct rq *rq)
         if (unlikely((s64)delta_exec < 0))
                 delta_exec = 0;
 
-        schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
+        schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));
 
         curr->se.sum_exec_runtime += delta_exec;
         account_group_exec_runtime(curr, delta_exec);