From nobody Mon Feb 9 23:15:34 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A438022154F for ; Fri, 16 Jan 2026 12:40:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768567231; cv=none; b=YL5PLvpiJeKdVM5yUI2B/XmeMxeoAI7482U60WQRuWFWQPGCWN1zntoAsC+xUMkfP2xgKCmlw+RGyjmAzdDn+Tu2dUCCwhzCwXRcoWiyVD16aSjL58p1ak8CjQsxB3a8JWl8iOhbX+wkW2kslqyMSSq7N+sl9Om1+h3VUKVXVF4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768567231; c=relaxed/simple; bh=YOh+WmjF31wq+7/wt12u5OvU27Q8rBeiXQ9dC6AT3H8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mHyukymD4UxVcOv8bFOPvV1SJ7NQ4UiwZr3B621AyFCIMZSg5RoZjDU42w/Sq6o+CNSNgv3KH6Q+wzjSXb1+uXCHuSiBtj+acaIDT9x2w4qJ8DoKsy+aL9bfA28KB8cSE/md2hr16IpEUYscvGYyv4pZJYPhzcLRnmsl+fJslco= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=hK9OwRsQ; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="hK9OwRsQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768567228; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bsinfdR1Sheg5tPjDYElGsfZJDd1jewwP9udfKybc04=; b=hK9OwRsQ8VeQuWEp49vkiSGvfeLpuzHCellyLAH78ZCEHL0rP/FkaVKSE5XzawMO/hlNvn 4Nasz4YIvF2OWqI8DTiTK0GSsqIWXHO7hbVSDkpfNyYYx2tPGBxriGSqBomrKpPm53ZKtw QrNqubYxltafkRWRcL5nIg9T3YcmCto= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-611--tsmu2GmMmewfCrJlqbCoA-1; Fri, 16 Jan 2026 07:40:25 -0500 X-MC-Unique: -tsmu2GmMmewfCrJlqbCoA-1 X-Mimecast-MFC-AGG-ID: -tsmu2GmMmewfCrJlqbCoA_1768567224 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 45BDF18005AE; Fri, 16 Jan 2026 12:40:24 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.csb (unknown [10.45.224.42]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E99C0195419D; Fri, 16 Jan 2026 12:40:19 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Steven Rostedt , Nam Cao , Juri Lelli , Masami Hiramatsu , Ingo Molnar , Peter Zijlstra , linux-trace-kernel@vger.kernel.org Cc: Gabriele Monaco , Tomas Glozar , Clark Williams , John Kacur Subject: [PATCH v4 10/15] sched: Add task enqueue/dequeue trace points Date: Fri, 16 Jan 2026 13:39:06 +0100 Message-ID: <20260116123911.130300-11-gmonaco@redhat.com> In-Reply-To: <20260116123911.130300-1-gmonaco@redhat.com> References: <20260116123911.130300-1-gmonaco@redhat.com> 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-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Content-Type: text/plain; charset="utf-8" From: Nam Cao Add trace points into enqueue_task() and dequeue_task(). Suggested-by: Peter Zijlstra Signed-off-by: Nam Cao Signed-off-by: Gabriele Monaco Reviewed-by: K Prateek Nayak --- include/trace/events/sched.h | 13 +++++++++++++ kernel/sched/core.c | 9 ++++++++- kernel/sched/sched.h | 2 ++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 366b2e8ec40c..f4e1d3554e3e 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -912,6 +912,19 @@ DECLARE_TRACE(sched_dl_server_stop, TP_PROTO(struct sched_dl_entity *dl_se, int cpu), TP_ARGS(dl_se, cpu)); =20 +/* + * The two trace points below may not work as expected for fair tasks due + * to delayed dequeue. See: + * https://lore.kernel.org/lkml/179674c6-f82a-4718-ace2-67b5e672fdee@amd.c= om/ + */ +DECLARE_TRACE(sched_enqueue, + TP_PROTO(struct task_struct *tsk, int cpu), + TP_ARGS(tsk, cpu)); + +DECLARE_TRACE(sched_dequeue, + TP_PROTO(struct task_struct *tsk, int cpu), + TP_ARGS(tsk, cpu)); + #endif /* _TRACE_SCHED_H */ =20 /* This part must be outside protection */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f6293fa02fb7..8958c013fb2c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2087,6 +2087,8 @@ unsigned long get_wchan(struct task_struct *p) =20 void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { + trace_sched_enqueue_tp(p, rq->cpu); + if (!(flags & ENQUEUE_NOCLOCK)) update_rq_clock(rq); =20 @@ -2114,6 +2116,8 @@ void enqueue_task(struct rq *rq, struct task_struct *= p, int flags) */ inline bool dequeue_task(struct rq *rq, struct task_struct *p, int flags) { + int ret; + if (sched_core_enabled(rq)) sched_core_dequeue(rq, p, flags); =20 @@ -2131,7 +2135,10 @@ inline bool dequeue_task(struct rq *rq, struct task_= struct *p, int flags) */ uclamp_rq_dec(rq, p); rq->queue_mask |=3D p->sched_class->queue_mask; - return p->sched_class->dequeue_task(rq, p, flags); + ret =3D p->sched_class->dequeue_task(rq, p, flags); + if (trace_sched_dequeue_tp_enabled() && !(flags & DEQUEUE_SLEEP)) + trace_sched_dequeue_tp(p, rq->cpu); + return ret; } =20 void activate_task(struct rq *rq, struct task_struct *p, int flags) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e885a935b716..8465472b40fa 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2918,6 +2918,8 @@ static inline void sub_nr_running(struct rq *rq, unsi= gned count) =20 static inline void __block_task(struct rq *rq, struct task_struct *p) { + trace_sched_dequeue_tp(p, rq->cpu); + if (p->sched_contributes_to_load) rq->nr_uninterruptible++; =20 --=20 2.52.0