From nobody Fri Dec 26 01:02:45 2025 Received: from m16.mail.163.com (m15.mail.163.com [45.254.50.220]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A80634878E for ; Wed, 10 Jan 2024 13:20:21 +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="UuX2BVFl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=mpOgP P0xKV58Qwv7Ooq5G/jaeJlpdbbBCzuHowdlvv0=; b=UuX2BVFlGAm6NfqTBZn+I g6gN0Jpcwamy4N4xWewIlxBbMXUdqnb3MjOuSE3zfmDg+yAO2C5I/zjlDEY8HGeV clOdBy26Vq0T13dr2b4bSIZQY9z3YGcIqCPagKPpPt5pKjxqya0oRnHKcmVPYeTg GFTkxOnIab3Oll9a239IPo= Received: from ubuntu.lan (unknown [120.229.70.208]) by gzga-smtp-mta-g0-0 (Coremail) with SMTP id _____wDXX5RumZ5l+HlXAA--.7591S2; Wed, 10 Jan 2024 21:19:44 +0800 (CST) From: Junwen Wu To: bristot@redhat.com, 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, vschneid@redhat.com, linux-kernel@vger.kernel.org, Junwen Wu Subject: [PATCH v4] sched/stats: Fix rt/dl task's sched latency statistics error in sched_stat_wait trace_point Date: Wed, 10 Jan 2024 13:19:40 +0000 Message-Id: <20240110131940.42979-1-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: _____wDXX5RumZ5l+HlXAA--.7591S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7CF15CF4fWw1UKw1DAFy5Jwb_yoW8Cryfp3 yDGaykJw4qg3yjgw4UZr4Du3yrWwn3J342gF93GayftF4Yyr1Yq3ZaqFW3XFZ09r95CF12 qr409rZrKw409F7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0piX4S7UUUUU= X-CM-SenderInfo: 5zxgtvxprqqiywtou0bp/1tbisQphbWVOA-hZVAADsp Content-Type: text/plain; charset="utf-8" The sched_stat_wait tracepoint is showing unreasonably long latencies for real-time tasks. For example: sched_stat_wait: comm=3Drcu_preempt pid=3D14 delay=3D4936139545261 [ns] This error happens when the rt task balances off the source CPU because the dequeue operation is not updating the sched_statistics. So, follow update_stats_wait_end_fair() and update the stats. Do the same for SCHED_DEADLINE. Signed-off-by: Junwen Wu --- kernel/sched/deadline.c | 5 ++++- kernel/sched/rt.c | 4 ++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index b28114478b82..4a9aad291fb9 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1558,10 +1558,13 @@ update_stats_dequeue_dl(struct dl_rq *dl_rq, struct= sched_dl_entity *dl_se, int flags) { struct task_struct *p =3D dl_task_of(dl_se); + struct rq *rq =3D rq_of_dl_rq(dl_rq); =20 if (!schedstat_enabled()) return; - + /* Mark the end of the wait period if dequeueing a waiting task.*/ + if (p && (p !=3D rq->curr)) + update_stats_wait_end_dl(dl_rq, dl_se); if ((flags & DEQUEUE_SLEEP)) { unsigned int state; =20 diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6aaf0a3d6081..5cb3a54d6b13 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1360,12 +1360,16 @@ 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