From nobody Sun Jun 21 02:30:14 2026 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 D01C3387344; Wed, 8 Apr 2026 11:20:11 +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=1775647216; cv=none; b=QG5P54gBIxc4WEUmPkKZqVfSWsuPrp92vM3q7uDld5pbmzbX8R6DqJkmBBTatw58VkmvfhLUN6xyRBrCpK41NGImW3Q16GX3/UszVQSdnNtVHh7a9RS4aQ2h41BtHzyYntAJ9cCCiheGq6QXNAmD8sa3YKqBoNRHYXYMaoabNN4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775647216; c=relaxed/simple; bh=5wg50Ai98pkvbFBFsWwao8e4ieGyjYKDweimipKoqDk=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=PSuc9szg4zzYZCU+IdNYQzP8xym4Dpg45QtBryzB2ZJ++42hd1tpt6GAcFN8azgIC/RAomY/zTkhVZ+63Ycm2vUBuXN8FDX6zZpt97ByeaAZgN/nvHzDJDH/we65Rg8X0bRGIdx1wgbYq1Q2a4b3ICVBYEpd+Q8s/fKDor8+sWQ= 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=zjAZBBNR; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=py+B9tkN; 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="zjAZBBNR"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="py+B9tkN" Date: Wed, 08 Apr 2026 11:20:08 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1775647209; 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=ISmfEU+qzbONwe31vNKQxoIyhTxX1y/5xUXPu4lotNA=; b=zjAZBBNRcnzdYofUkapUBQD8fM53+hcxRj0bZU/6UZGlf66y5mNd0EXa3OUTt2pFWifbIX ep/s8L/HeCHX2AnE5d0P5A4sRxjr0QXatMTiEMLIoR/YGXq+C55aXZ26k/MECp6dZEHLaK 3wOlqoZCqWduHdksXibFsx/Zahp/nnnoDF4sjooguFbOMvsFQ0j/dVEPvZ4xCATjr6e5DH Z6Yi7/TSvJxFPW/4lVSY97g5CDUGSnSPHzwIyvDDqcaRYmq0W1wr9D0qPc0Dcr0qMW/E3G 2Op1qPk9IUIERbXBcvzVQst7a4kUMopz9xGY6PUtnV+vDtOVS0bhuz1Zax+Iig== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1775647209; 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=ISmfEU+qzbONwe31vNKQxoIyhTxX1y/5xUXPu4lotNA=; b=py+B9tkNI6IzEcap3ure1XYT4meuLH9DyxpTtkunzMh1WWI5kuhwVMUx+hYzxNlTfYE9Ts eSFKX3X40Rb0VnBw== From: tip-bot2 for Michal =?utf-8?q?Koutn=C3=BD?= Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/rt: Skip group schedulable check with rt_group_sched=0 Cc: mkoutny@suse.com, "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20260323-sched-rert_groups-v3-1-1e7d5ed6b249@suse.com> References: <20260323-sched-rert_groups-v3-1-1e7d5ed6b249@suse.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177564720855.801717.2170924895837940091.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: 8b016dcec9365675be81d26be88f2c09cf983bd4 Gitweb: https://git.kernel.org/tip/8b016dcec9365675be81d26be88f2c09c= f983bd4 Author: Michal Koutn=C3=BD AuthorDate: Mon, 23 Mar 2026 13:39:37 +01:00 Committer: Peter Zijlstra CommitterDate: Wed, 08 Apr 2026 13:11:44 +02:00 sched/rt: Skip group schedulable check with rt_group_sched=3D0 The warning from the commit 87f1fb77d87a6 ("sched: Add RT_GROUP WARN checks for non-root task_groups") is wrong -- it assumes that only task_groups with rt_rq are traversed, however, the schedulability check would iterate all task_groups even when rt_group_sched=3D0 is disabled at boot time but some non-root task_groups exist. The schedulability check is supposed to validate: a) that children don't overcommit its parent, b) no RT task group overcommits global RT limit. but with rt_group_sched=3D0 there is no (non-trivial) hierarchy of RT group= s, therefore skip the validation altogether. Otherwise, writes to the global sched_rt_runtime_us knob will be rejected with incorrect validation error. This fix is immaterial with CONFIG_RT_GROUP_SCHED=3Dn. Fixes: 87f1fb77d87a6 ("sched: Add RT_GROUP WARN checks for non-root task_gr= oups") Signed-off-by: Michal Koutn=C3=BD Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260323-sched-rert_groups-v3-1-1e7d5ed6b249= @suse.com --- kernel/sched/rt.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index a48e867..893e54d 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2690,9 +2690,6 @@ static int tg_rt_schedulable(struct task_group *tg, v= oid *data) tg->rt_bandwidth.rt_runtime && tg_has_rt_tasks(tg)) return -EBUSY; =20 - if (WARN_ON(!rt_group_sched_enabled() && tg !=3D &root_task_group)) - return -EBUSY; - total =3D to_ratio(period, runtime); =20 /* @@ -2836,6 +2833,8 @@ long sched_group_rt_period(struct task_group *tg) static int sched_rt_global_constraints(void) { int ret =3D 0; + if (!rt_group_sched_enabled()) + return ret; =20 mutex_lock(&rt_constraints_mutex); ret =3D __rt_schedulable(NULL, 0, 0);