[RFC PATCH] sched/stats: Add missing schedstats update for sched_delayed tasks

Xuewen Yan posted 1 patch 1 year ago
kernel/sched/fair.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
[RFC PATCH] sched/stats: Add missing schedstats update for sched_delayed tasks
Posted by Xuewen Yan 1 year ago
Because sched-delayed tasks do not leave the runqueue,
if they are woken up and re-queued before becoming eligible,
the wait and sleep-related information in schedstat is not updated.

So add the dequeue/enqueue update for the sched-delayed queue.

Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
---
 kernel/sched/fair.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 29ee1ce17036..b0a786e2c074 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5340,8 +5340,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	if (flags & ENQUEUE_MIGRATED)
 		se->exec_start = 0;
 
-	check_schedstat_required();
-	update_stats_enqueue_fair(cfs_rq, se, flags);
+	if (!se->sched_delayed) {
+		check_schedstat_required();
+		update_stats_enqueue_fair(cfs_rq, se, flags);
+	}
 	if (!curr)
 		__enqueue_entity(cfs_rq, se);
 	se->on_rq = 1;
@@ -5458,6 +5460,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 		    !entity_eligible(cfs_rq, se)) {
 			update_load_avg(cfs_rq, se, 0);
 			set_delayed(se);
+			update_stats_dequeue_fair(cfs_rq, se, flags);
 			return false;
 		}
 	}
@@ -5477,7 +5480,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	update_load_avg(cfs_rq, se, action);
 	se_update_runnable(se);
 
-	update_stats_dequeue_fair(cfs_rq, se, flags);
+	/* Do not update twice for delayed task */
+	if (!se->sched_delayed)
+		update_stats_dequeue_fair(cfs_rq, se, flags);
 
 	update_entity_lag(cfs_rq, se);
 	if (sched_feat(PLACE_REL_DEADLINE) && !sleep) {
@@ -6933,6 +6938,8 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 
 	if (flags & ENQUEUE_DELAYED) {
 		requeue_delayed_entity(se);
+		check_schedstat_required();
+		update_stats_enqueue_fair(cfs_rq_of(se), se, flags);
 		return;
 	}
 
-- 
2.25.1