schedstat: consolidate per-task cpu runtime stats

Impact: simplify code

When we turn on CONFIG_SCHEDSTATS, per-task cpu runtime is accumulated
twice. Once in task->se.sum_exec_runtime and once in sched_info.cpu_time.
These two stats are exactly the same.

Given that task->se.sum_exec_runtime is always accumulated by the core
scheduler, sched_info can reuse that data instead of duplicate the accounting.

Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 2 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8cccd6dc5d66..2d1e840ddd35 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -670,8 +670,7 @@ struct reclaim_state;
 struct sched_info {
         /* cumulative counters */
         unsigned long pcount;         /* # of times run on this cpu */
-        unsigned long long cpu_time,  /* time spent on the cpu */
-                           run_delay; /* time spent waiting on a runqueue */
+        unsigned long long run_delay; /* time spent waiting on a runqueue */
 
         /* timestamps */
         unsigned long long last_arrival,/* when we last ran on a cpu */