From nobody Tue Oct 7 05:33:22 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 6493D243968; Mon, 14 Jul 2025 09:10:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752484248; cv=none; b=bQm/lkiQtKazZlK+B50RNFfb5e7tXxewgFVRxbDu9/QBw+WO6iKRivZz2oT2GS+u4z7VXBAxX9G0RBUNC+xxcwgBXnCYshYG5iiGNV5vrk67XY43gFOsV9aULHSDtzzLE5OekHtD7h4ntY9esWlBiUXSAIHfOQP1mkCZQg0UCQg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752484248; c=relaxed/simple; bh=C8pHY8tQC8gzi/NzuDfOnx5v8PL9stBfk3MAhdFVrdo=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=Jqp/H0GuzURThfIc8n0J6bJDXHhyjnebqobaFLh/0MWNH5fQMJDBFvXaiyfsqJsVWL7SliGq6+n/k/Aa+pmj6l5ocFXqksn1gyhPgq/+LxYuXcdwQW8jVBErhmj8mgnkMVF/A+3gu9AvV7pCB7rASh9RiI9nedCGGEjYrOkHaz0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=dXdO2GQl; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=v16ewYC3; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dXdO2GQl"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="v16ewYC3" Date: Mon, 14 Jul 2025 09:10:43 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1752484244; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mxeCeIvQrwV1zYihyuPeziQ2sZ+dX8OxMS3PaBSJnE8=; b=dXdO2GQlbXVei1uyuazrmN4PdyqcWEJMoFd8MjZNMFXVYyYSAfOFEnNlmmZma1q/7N3YDJ A7LQtStKCSVnNwFU6AeKjdkiCwN/mM6Qt/YYdw7SJHDUL3hMqw/jxdhuRrTB7XVeDQ0+/H qAxcrMasQmcXdzKYDGtC87CL9m7SsPEYhSKsBUjunDJYD662nc4b59HZka6y9a151GV2yG kNAl7sHeNurVBzcsDyqUjtAHQOFAMVhdDrnEwunyWx1eVtNO0F4iIdk24Oj91pJZsq3c1C kIE0wOmb5eywFSpQASCTCEpHEQwMdaTd4Ep8T41gQGZxR0XF9R4QTvofh4cQEQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1752484244; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mxeCeIvQrwV1zYihyuPeziQ2sZ+dX8OxMS3PaBSJnE8=; b=v16ewYC3dDFbIWrDx1WsqD2H4xwPUcRrpja+UQHz9r0rUOSjf8RXV2o+te4tpt0KQp4n9F Iv5wUv/RR2K/HVDg== From: "tip-bot2 for Juri Lelli" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/deadline: Initialize dl_servers after SMP Cc: Marcel Ziswiler , Juri Lelli , "Peter Zijlstra (Intel)" , Waiman Long , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250627115118.438797-2-juri.lelli@redhat.com> References: <20250627115118.438797-2-juri.lelli@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175248424304.406.9479462804989012657.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the sched/core branch of tip: Commit-ID: 9f239df55546ee1d28f0976130136ffd1cad0fd7 Gitweb: https://git.kernel.org/tip/9f239df55546ee1d28f0976130136ffd1= cad0fd7 Author: Juri Lelli AuthorDate: Fri, 27 Jun 2025 13:51:14 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 14 Jul 2025 10:59:32 +02:00 sched/deadline: Initialize dl_servers after SMP dl-servers are currently initialized too early at boot when CPUs are not fully up (only boot CPU is). This results in miscalculation of per runqueue DEADLINE variables like extra_bw (which needs a stable CPU count). Move initialization of dl-servers later on after SMP has been initialized and CPUs are all online, so that CPU count is stable and DEADLINE variables can be computed correctly. Fixes: d741f297bceaf ("sched/fair: Fair server interface") Reported-by: Marcel Ziswiler Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Tested-by: Marcel Ziswiler # nuc & rock5b Link: https://lore.kernel.org/r/20250627115118.438797-2-juri.lelli@redhat.c= om --- kernel/sched/core.c | 2 ++- kernel/sched/deadline.c | 48 +++++++++++++++++++++++++--------------- kernel/sched/sched.h | 1 +- 3 files changed, 33 insertions(+), 18 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2f8caa9..89b3ed6 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8371,6 +8371,8 @@ void __init sched_init_smp(void) init_sched_rt_class(); init_sched_dl_class(); =20 + sched_init_dl_servers(); + sched_smp_initialized =3D true; } =20 diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 23668fc..0d25553 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -761,6 +761,8 @@ static inline void setup_new_dl_entity(struct sched_dl_= entity *dl_se) struct dl_rq *dl_rq =3D dl_rq_of_se(dl_se); struct rq *rq =3D rq_of_dl_rq(dl_rq); =20 + update_rq_clock(rq); + WARN_ON(is_dl_boosted(dl_se)); WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline)); =20 @@ -1585,23 +1587,7 @@ void dl_server_start(struct sched_dl_entity *dl_se) { struct rq *rq =3D dl_se->rq; =20 - /* - * XXX: the apply do not work fine at the init phase for the - * fair server because things are not yet set. We need to improve - * this before getting generic. - */ - if (!dl_server(dl_se)) { - u64 runtime =3D 50 * NSEC_PER_MSEC; - u64 period =3D 1000 * NSEC_PER_MSEC; - - dl_server_apply_params(dl_se, runtime, period, 1); - - dl_se->dl_server =3D 1; - dl_se->dl_defer =3D 1; - setup_new_dl_entity(dl_se); - } - - if (!dl_se->dl_runtime || dl_se->dl_server_active) + if (!dl_server(dl_se) || dl_se->dl_server_active) return; =20 dl_se->dl_server_active =3D 1; @@ -1612,7 +1598,7 @@ void dl_server_start(struct sched_dl_entity *dl_se) =20 void dl_server_stop(struct sched_dl_entity *dl_se) { - if (!dl_se->dl_runtime) + if (!dl_server(dl_se) || !dl_server_active(dl_se)) return; =20 dequeue_dl_entity(dl_se, DEQUEUE_SLEEP); @@ -1645,6 +1631,32 @@ void dl_server_init(struct sched_dl_entity *dl_se, s= truct rq *rq, dl_se->server_pick_task =3D pick_task; } =20 +void sched_init_dl_servers(void) +{ + int cpu; + struct rq *rq; + struct sched_dl_entity *dl_se; + + for_each_online_cpu(cpu) { + u64 runtime =3D 50 * NSEC_PER_MSEC; + u64 period =3D 1000 * NSEC_PER_MSEC; + + rq =3D cpu_rq(cpu); + + guard(rq_lock_irq)(rq); + + dl_se =3D &rq->fair_server; + + WARN_ON(dl_server(dl_se)); + + dl_server_apply_params(dl_se, runtime, period, 1); + + dl_se->dl_server =3D 1; + dl_se->dl_defer =3D 1; + setup_new_dl_entity(dl_se); + } +} + void __dl_server_attach_root(struct sched_dl_entity *dl_se, struct rq *rq) { u64 new_bw =3D dl_se->dl_bw; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 105190b..3058fb6 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -385,6 +385,7 @@ extern void dl_server_stop(struct sched_dl_entity *dl_s= e); extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, dl_server_has_tasks_f has_tasks, dl_server_pick_f pick_task); +extern void sched_init_dl_servers(void); =20 extern void dl_server_update_idle_time(struct rq *rq, struct task_struct *p);