From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m15.mail.163.com (m15.mail.163.com [45.254.50.219]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0744C46AD for ; Sat, 23 Dec 2023 05:38:32 +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="NeQoklkv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=o7hwV 3qd1r+M+fgyqUOI5ooAyBPaGQyd0qEIr2EUceA=; b=NeQoklkvkKCBc3zVgO5Cu xW3u8bVBieOmytycj1/fw6sUd8rOnJih3x91cq5ndHBfDSdZuriPX3jhh/L+zWqn ZIEjsF5AdeWizM8gcfWSL9exdXp7H0DuWV7NQQBT70AFubq5cpiI9Hntu9WG/Vp6 +PM0RD+INaD98cLkibeK4o= Received: from ubuntu.lan (unknown [223.74.158.232]) by zwqz-smtp-mta-g0-3 (Coremail) with SMTP id _____wCXv7nncYZlGKjPGQ--.35408S2; Sat, 23 Dec 2023 13:36:42 +0800 (CST) From: Junwen Wu To: laoar.shao@gmail.com Cc: bristot@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, vincent.guittot@linaro.org, vschneid@redhat.com, wudaemon@163.com Subject: Re: [PATCH v2] sched/rt: Fix rt task's sched latency statistics error in sched_stat_wait trace_point Date: Sat, 23 Dec 2023 05:36:34 +0000 Message-Id: <20231223053634.942784-1-wudaemon@163.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wCXv7nncYZlGKjPGQ--.35408S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7uFy3WFWfurW8Kw4DZF4rAFb_yoW8Kw4fpw 4qgaykJw4qq3y0q3yxZrsrGr45uwn3J342qFnrGFWxtF4Yyr1FqFn0g343WrWqgr9Y9F17 ta18K39xKa1v9F7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0JU3b18UUUUU= X-CM-SenderInfo: 5zxgtvxprqqiywtou0bp/1tbisQtPbWVOAoVlVwAAsG >It seems DL has the same issue. Pls. also fix it in update_stats_dequeue_dl(). >And add the Fixes tag in the commit log: >Fixes: 57a5c2dafca8 ("sched/rt: Support schedstats for RT sched class") >Fixes: b5eb4a5f6521 ("sched/dl: Support schedstats for deadline sched class") ok, the PATCH v3 below is ok? Subject: [PATCH v3] sched/stats: Fix rt/dl task's sched latency statistics error in sched_stat_wait trace_point When enable sched_stat_wait trace_point, some rt tasks sched latency so long, like this, sched_stat_wait: comm=rcu_preempt pid=14 delay=4936139545261 [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, so do dl tasks. Fixes: 57a5c2dafca8 ("sched/rt: Support schedstats for RT sched class") Fixes: b5eb4a5f6521 ("sched/dl: Support schedstats for deadline sched class") Signed-off-by: Junwen Wu --- kernel/sched/deadline.c | 8 +++++++- kernel/sched/rt.c | 7 +++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index b28114478b82..29223163ee22 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1558,10 +1558,16 @@ update_stats_dequeue_dl(struct dl_rq *dl_rq, struct sched_dl_entity *dl_se, int flags) { struct task_struct *p = dl_task_of(dl_se); + struct rq *rq = rq_of_dl_rq(dl_rq); if (!schedstat_enabled()) return; - + /* + * Mark the end of the wait period + * if dequeueing a waiting task. + */ + if (p && (p != rq->curr)) + update_stats_wait_end_dl(dl_rq, dl_se); if ((flags & DEQUEUE_SLEEP)) { unsigned int state; 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 = NULL; + struct rq *rq = rq_of_rt_se(rt_se); if (!schedstat_enabled()) return; if (rt_entity_is_task(rt_se)) p = rt_task_of(rt_se); + /* + * Mark the end of the wait period + * if dequeueing a waiting task. + */ + if (p && (p != rq->curr)) + update_stats_wait_end_rt(rt_rq, rt_se); if ((flags & DEQUEUE_SLEEP) && p) { unsigned int state; -- Best regards