From nobody Fri Apr 10 08:06:48 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 9C22B1B041E for ; Mon, 24 Feb 2025 13:30:28 +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=1740403830; cv=none; b=kjOuHScBpJvyVAGi95tFl+w/hBCaXvMZ6xa7L5c5i8RaOWTgzSnEkTvUPUEhVjOtFRzpXz9hfR7/I44/IQg5VuA+R/6VuJaFfOilpFNMPEzB1FnpUpucXpes3Wp9B55TftK/KGqKzQfrACcJekvQUIXusi27coQvNAhX0sLKGHY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740403830; c=relaxed/simple; bh=ccQbInSJuDgG4sw8vogAZkr4ne/RKhkHsD74iHvxLoQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DM5+ePA1RmJ2oJZ9lRj6hsdI2LX/q0gUUiu4merICKMqzxLGTzoDEDzEIYyrNGYHhJFZLkd/Hvkwp7usZZ9QwQ+O8P1sNecJEPYqVbEmVTIioLoyzfmLDBgi+/O2KBVfAcyhr5YkzbtGZdrRP0h3anE53lFFANVAElpMVbJ7oJY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=J1x5dOkx; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="J1x5dOkx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740403827; 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=NrLWlxK4LeUO1BVII3k81u8NXSEVeDE8KUCfCI4VAKg=; b=J1x5dOkxHS73npXYiq5YZ2t8qqNvQE5oKpCIH1KtSRk50+sTpBVWAkoq87t3azIM16cSaT 7v9T1u4ak9Bygauzds4zjtY/yPikmVSM8qSkLlUpUYebOQzF4Wwv6o4qzH+/+QFOq2CZi4 nL80C25pCwej+mBl+5WrCHyvPf8x3AU= Received: from mx-prod-mc-04.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-637-KRI0AH-eP2Spq0BsrXpUrQ-1; Mon, 24 Feb 2025 08:30:24 -0500 X-MC-Unique: KRI0AH-eP2Spq0BsrXpUrQ-1 X-Mimecast-MFC-AGG-ID: KRI0AH-eP2Spq0BsrXpUrQ_1740403823 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C653D19039C5; Mon, 24 Feb 2025 13:30:17 +0000 (UTC) Received: from gmonaco-thinkpadt14gen3.rmtit.com (unknown [10.45.226.36]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id DB2D719560AE; Mon, 24 Feb 2025 13:30:14 +0000 (UTC) From: Gabriele Monaco To: linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra Cc: Gabriele Monaco , Mathieu Desnoyers , Ingo Molnar , "Paul E. McKenney" , Shuah Khan Subject: [PATCH v9 1/3] sched: Add prev_sum_exec_runtime support for RT, DL and SCX classes Date: Mon, 24 Feb 2025 14:28:33 +0100 Message-ID: <20250224132836.383041-2-gmonaco@redhat.com> In-Reply-To: <20250224132836.383041-1-gmonaco@redhat.com> References: <20250224132836.383041-1-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 10.30.177.15 Content-Type: text/plain; charset="utf-8" The fair scheduling class relies on prev_sum_exec_runtime to compute the duration of the task's runtime since it was last scheduled. This value is currently not required by other scheduling classes but can be useful to understand long running tasks and take certain actions (e.g. during a scheduler tick). Add support for prev_sum_exec_runtime to the RT, deadline and sched_ext classes by simply assigning the sum_exec_runtime at each set_next_task. Cc: Mathieu Desnoyers Signed-off-by: Gabriele Monaco Reviewed-by: Mathieu Desnoyers --- kernel/sched/deadline.c | 1 + kernel/sched/ext.c | 1 + kernel/sched/rt.c | 1 + 3 files changed, 3 insertions(+) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 38e4537790af7..438b3a953d6c7 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2391,6 +2391,7 @@ static void set_next_task_dl(struct rq *rq, struct ta= sk_struct *p, bool first) p->se.exec_start =3D rq_clock_task(rq); if (on_dl_rq(&p->dl)) update_stats_wait_end_dl(dl_rq, dl_se); + p->se.prev_sum_exec_runtime =3D p->se.sum_exec_runtime; =20 /* You can't push away the running task */ dequeue_pushable_dl_task(rq, p); diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 5a81d9a1e31f2..feaed0459eb92 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2974,6 +2974,7 @@ static void set_next_task_scx(struct rq *rq, struct t= ask_struct *p, bool first) } =20 p->se.exec_start =3D rq_clock_task(rq); + p->se.prev_sum_exec_runtime =3D p->se.sum_exec_runtime; =20 /* see dequeue_task_scx() on why we skip when !QUEUED */ if (SCX_HAS_OP(running) && (p->scx.flags & SCX_TASK_QUEUED)) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 4b8e33c615b12..1ea272e4dae71 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1684,6 +1684,7 @@ static inline void set_next_task_rt(struct rq *rq, st= ruct task_struct *p, bool f p->se.exec_start =3D rq_clock_task(rq); if (on_rt_rq(&p->rt)) update_stats_wait_end_rt(rt_rq, rt_se); + p->se.prev_sum_exec_runtime =3D p->se.sum_exec_runtime; =20 /* The running task is never eligible for pushing */ dequeue_pushable_task(rq, p); --=20 2.48.1