From nobody Mon Feb 9 08:28:39 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 7784735B64B for ; Thu, 22 Jan 2026 15:56:13 +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=1769097379; cv=none; b=rrbNTi5Fq/yEFF3R+KIuvWtsIq5XPHydEombi98UY8N2jwxc0Bdm2CE/43eO2N3D0XH1psJvgPIKdBTufkNtJ158fX0SZU9YQnnm5bJ5Vy4Uw8TfIqV0DHZplKslvFZCa1bVMyCEah2qmsXwZYItJJS/e00eDggS7oKkE+Yr+Qg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769097379; c=relaxed/simple; bh=1pJS8p7mvN6ekb5St5kQqPvKFbasicPmXPkXEuKwWgE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Cr+Mb/iu4V0ZA9/cxZvqmN6lsRMhzCY+iYf10pSlZyeDEg7rZQb39NQM69N0QdjWV8f2JmMd9ncxORqPEhvP0G5h5F4Q3G3Gx2Iol8d0yiUTqF+uNpc+BOV0RzfmVcQhUOWuI+BgGX4Z5OVS1kDgDjrs9Co82jopACq0ZpO85mg= 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=JnVSjEnQ; 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="JnVSjEnQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1769097370; 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=vco0j0lkHfCH6pZRJLJvq8VCvHhRuKi9gXcEPZmw6uo=; b=JnVSjEnQSEn1RjRoffT7VkeZ6a5rHzqelUoZ1KPA7RxbeQUth4y0+f2qOgll/seNogBFUl FJHalaGw9APDeZfcbEqkg51ZXZwFu3QiXcCeJsJKZwtLzRqobZQ3i9OGnt6hFbIemny+wO xrAbZWcE6zRgD+HoNn7lm/r+jinC8bI= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-423-BfYqMwq6M6WS2NNHvEwx5g-1; Thu, 22 Jan 2026 10:56:06 -0500 X-MC-Unique: BfYqMwq6M6WS2NNHvEwx5g-1 X-Mimecast-MFC-AGG-ID: BfYqMwq6M6WS2NNHvEwx5g_1769097365 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5E6501955D9F; Thu, 22 Jan 2026 15:56:05 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.csb (unknown [10.45.224.47]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 4579B1800240; Thu, 22 Jan 2026 15:55:59 +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: K Prateek Nayak , Gabriele Monaco , Tomas Glozar , Clark Williams , John Kacur Subject: [PATCH v5 09/15] sched: Add task enqueue/dequeue trace points Date: Thu, 22 Jan 2026 16:54:54 +0100 Message-ID: <20260122155500.362683-10-gmonaco@redhat.com> In-Reply-To: <20260122155500.362683-1-gmonaco@redhat.com> References: <20260122155500.362683-1-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 3.4.1 on 10.30.177.111 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 Reviewed-by: K Prateek Nayak Signed-off-by: Gabriele Monaco --- Notes: V5: * Do not fire enqueue tracepoint for delayed enqueues include/trace/events/sched.h | 13 +++++++++++++ kernel/sched/core.c | 10 +++++++++- kernel/sched/sched.h | 2 ++ 3 files changed, 24 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..c885d7885172 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2087,6 +2087,9 @@ unsigned long get_wchan(struct task_struct *p) =20 void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { + if (trace_sched_enqueue_tp_enabled() && !(flags & ENQUEUE_DELAYED)) + trace_sched_enqueue_tp(p, rq->cpu); + if (!(flags & ENQUEUE_NOCLOCK)) update_rq_clock(rq); =20 @@ -2114,6 +2117,8 @@ 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 +2136,10 @@ 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