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>

1 files changed, 25 insertions, 29 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