From nobody Sat Dec 27 10:58:44 2025 Received: from m15.mail.163.com (m15.mail.163.com [45.254.50.219]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 25F5E539F7 for ; Thu, 21 Dec 2023 15:03:30 +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="jSoF5Ebn" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=wxvSD Li8T65lvh5EvTZQCJASQPtLkSwryZZLIIX8yC0=; b=jSoF5EbnbK07t/MiYUm2l wSfdYgrQzo1DXwC7fzJx0/RYm/SufECkaYwm3yfqi9Gylbrgq961fir5/KB7O3iI hEp8H2BWjzrg85msFeKLr7uXR7t7TA6GO1wTqk5K/AAOKkEZhKyTcMqdhGI98Vg1 wx/3gO3idv9CReA6lOONvc= Received: from localhost.localdomain (unknown [120.229.19.61]) by zwqz-smtp-mta-g0-1 (Coremail) with SMTP id _____wDnb4aSU4Rl_YYfEQ--.29751S2; Thu, 21 Dec 2023 23:02:45 +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 v2] sched/rt: Fix rt task's sched latency statistics error in sched_stat_wait trace_point Date: Thu, 21 Dec 2023 15:02:38 +0000 Message-Id: <20231221150238.856960-1-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: _____wDnb4aSU4Rl_YYfEQ--.29751S2 X-Coremail-Antispam: 1Uf129KBjvJXoWrZF17Zw1UtF4ktryUtryDGFg_yoW8Jr45p3 909a92va1qqay2qa1xuFs7ur15Wwn3J342gF97Jw1ftF4Yyrn0qwnIvw4agrWv9rykCF1x tF40yrZxKa10vFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0piKZX7UUUUU= X-CM-SenderInfo: 5zxgtvxprqqiywtou0bp/1tbisBRNbWV4G7fD9QABsC 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. When rt task balance off source cpu, dequeue operation not update the sched_statistics, so follow update_stats_wait_end_fair update method. Signed-off-by: Junwen Wu Acked-by: Yafang Shao --- Changes since v1: https://lore.kernel.org/all/20231218150322.788382-1-wudaemon@163.com/ kernel/sched/rt.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6aaf0a3d6081..6a2600213991 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1360,12 +1360,19 @@ 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); + /* + * Mark the end of the wait period + * if dequeueing a waiting task. + */ + if (p && (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