[PATCH v3 12/20] sched/debug: Add migration stats due to non preferred CPUs

[Shrikanth Hegde]

Add new stats.
- nr_migrations_cpu_non_preferred: number of migrations happened since
  a CPU was marked as non preferred due to high steal time.

Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
---
 include/linux/sched.h | 1 +
 kernel/sched/core.c   | 1 +
 kernel/sched/debug.c  | 1 +
 3 files changed, 3 insertions(+)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2c3ad3e0edb5..dcfb57c90850 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -554,6 +554,7 @@ struct sched_statistics {
 	u64				nr_failed_migrations_running;
 	u64				nr_failed_migrations_hot;
 	u64				nr_forced_migrations;
+	u64				nr_migrations_cpu_non_preferred;
 
 	u64				nr_wakeups;
 	u64				nr_wakeups_sync;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 508773e71929..0d1995c65ce6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11287,6 +11287,7 @@ static int sched_non_preferred_cpu_push_stop(void *arg)
 	if (task_rq(p) == rq && task_on_rq_queued(p)) {
 		cpu = select_fallback_rq(rq->cpu, p);
 		rq = __migrate_task(rq, &rf, p, cpu);
+		schedstat_inc(p->stats.nr_migrations_cpu_non_preferred);
 	}
 
 	rq_unlock(rq, &rf);
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index f8a43fc13564..482c86a0ff80 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -1305,6 +1305,7 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
 		P_SCHEDSTAT(nr_failed_migrations_running);
 		P_SCHEDSTAT(nr_failed_migrations_hot);
 		P_SCHEDSTAT(nr_forced_migrations);
+		P_SCHEDSTAT(nr_migrations_cpu_non_preferred);
 		P_SCHEDSTAT(nr_wakeups);
 		P_SCHEDSTAT(nr_wakeups_sync);
 		P_SCHEDSTAT(nr_wakeups_migrate);
-- 
2.47.3