From nobody Sun Dec 14 20:16:00 2025 Received: from m15.mail.163.com (m15.mail.163.com [45.254.50.220]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E21AC3A1C4 for ; Mon, 18 Dec 2023 15:04:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="b3rdgRR0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=yVVj0 ms6yYbBhgiPzB8MS/3H+dwi2Xyw+iNQAT3pKkI=; b=b3rdgRR0bvzFTd8qK2rJh RiGeEqpkCqWTJacVdEP7814JwrchIJCdniarIbPOrEVqg8Zau9hGawmV8PWdbr76 90mKi1wzGXsQtt/W3nbrSIOoyAZ021dITxh0ye3Cwq27bD1a08OFoRAMikRXAWkL lugsQ4kliFAidmKxueJu7c= Received: from localhost.localdomain (unknown [120.229.19.179]) by zwqz-smtp-mta-g1-4 (Coremail) with SMTP id _____wDXX6I8X4Bl7UDSFw--.52364S2; Mon, 18 Dec 2023 23:03:25 +0800 (CST) From: Junwen Wu To: mingo@redhat.com, laoar.shao@gmail.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com Cc: mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, Junwen Wu Subject: [PATCH v1] sched/rt: Fix rt task's sched latency statistics in sched_stat_wait trace_point Date: Mon, 18 Dec 2023 15:03:22 +0000 Message-Id: <20231218150322.788382-1-wudaemon@163.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wDXX6I8X4Bl7UDSFw--.52364S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrZF17Zw1UtF4kurWxtr1UWrg_yoWDuFgEq3 sa9w4qkwn09Fn8tF43Gw4fXryrtayjqFn5Za18tFWDCrykJrZ8tas8KFs5Gws3Xws7AFWq krs2ga4vkrs7ujkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7xRKVyxJUUUUU== X-CM-SenderInfo: 5zxgtvxprqqiywtou0bp/1tbisR5KbWVOAiFeyAAAsW Content-Type: text/plain; charset="utf-8" When enable sched_stat_wait trace_point, some rt tasks sched latency so long, like this: sched_stat_wait: comm=3Drcu_preempt pid=3D14 delay=3D4936139545261 [ns] Rt task has low latency, it must have a bug. I found the reason is=20 When rt task balance off source cpu, dequeue operation not update=20 the sched_statistics, so follow update_stats_wait_end_fair update method. Signed-off-by: Junwen Wu --- kernel/sched/rt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6aaf0a3d6081..c75215947c20 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1360,12 +1360,15 @@ update_stats_dequeue_rt(struct rt_rq *rt_rq, struct= sched_rt_entity *rt_se, int flags) { struct task_struct *p =3D NULL; + struct rq *rq =3D rq_of_rt_se(rt_se); =20 if (!schedstat_enabled()) return; =20 if (rt_entity_is_task(rt_se)) p =3D rt_task_of(rt_se); + if (p !=3D rq->curr) + update_stats_wait_end_rt(rt_rq, rt_se); =20 if ((flags & DEQUEUE_SLEEP) && p) { unsigned int state; --=20 2.34.1