linux-kernel - [RFC PATCH] sched/stats: Add missing schedstats update for sched

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20250304085553.3367-1-xuewen.yan@unisoc.com>
Date: Tue, 4 Mar 2025 16:55:53 +0800
From: Xuewen Yan <xuewen.yan@...soc.com>
To: <mingo@...hat.com>, <peterz@...radead.org>, <juri.lelli@...hat.com>,
        <vincent.guittot@...aro.org>, <dietmar.eggemann@....com>
CC: <rostedt@...dmis.org>, <bsegall@...gle.com>, <mgorman@...e.de>,
        <vschneid@...hat.com>, <linux-kernel@...r.kernel.org>,
        <ke.wang@...soc.com>, <di.shen@...soc.com>, <xuewen.yan94@...il.com>
Subject: [RFC PATCH] sched/stats: Add missing schedstats update for sched_delayed tasks

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@...soc.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