From nobody Sun Feb 8 13:46:57 2026 Received: from mail-ej1-f44.google.com (mail-ej1-f44.google.com [209.85.218.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8134B1CA84 for ; Mon, 10 Feb 2025 15:13:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739200383; cv=none; b=Hv1CgA85HtJ8edAZP+Mo+pj05y++uqWmkE3e5yWogax7twKa9rLZ5cgLfwHlTIJuMrdvXh8r3qkJ5UACTjEenIPy1daXknbgAywFGIMWPPGvczcNQROBbfATja9NX7egNHnWu0rk0mFXPASqACs1kxX5sjrpIuxnyMNheHRAbwQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739200383; c=relaxed/simple; bh=NEXQa8SMxoUZIhEM2LZtR5hPu3GN/muNBmbxrg6/Pks=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PhJmYoxvKK05uCZN2ols/tNsxQp1V6SPZ4ByokAwMOqMKFstZHFG4nvSV2eiV00/OMbwDaPJOPM7QDakjfd+x4Y4wSr4tKxzB5c3E6oY/j9vt+1slek4TREjdAsNLWMNH/a26MXsyxxkC8/GdQtVyY99+KHWkbwa1dBp/QxBkgo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=XR/xLSMG; arc=none smtp.client-ip=209.85.218.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="XR/xLSMG" Received: by mail-ej1-f44.google.com with SMTP id a640c23a62f3a-aaec111762bso1086868066b.2 for ; Mon, 10 Feb 2025 07:13:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1739200379; x=1739805179; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=HcDctnJZ8SS/Sh/C+IjYe92Zf0/KDo0yTr6Uc7WvnrA=; b=XR/xLSMGiZHIg/MK+pj/LhzN6/y515tyAMHM3+D99T5oQdWbivvYEyT8cZ3HEY5mKl 6CGIQkxK9Uo+31Kg253/noB3nuTf5O+8nLTZ2KDwQN1DQIVB0xF1A9T4JxTI11BQ0AsG TjO/jB7bOPkAvEqIeVE9nlDsXhpIYDpEeVQEuL8YZcOVd/9bwtPilYUV13K1q5R7bOAq laLQHW0Gv/R1tlvyJ6ZPhRRm5tr2bz5oG11Kdy7dPIvSYGzTclqKKgaiwYpBPPSsBu6P j6BMJDGRNvKYDypUOxAjGkgT1CTBa5qJK4YwMeYzZ79u1hG/bc7wfkMk1q33qtclfSub aP5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739200379; x=1739805179; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=HcDctnJZ8SS/Sh/C+IjYe92Zf0/KDo0yTr6Uc7WvnrA=; b=GmEqgrSftu/br/GS5evPibfFVLs+qdpUsLkXgi7Y7pthWcVqAPVbwHqDsY5jltFZPh +20V2VkgndSApUtCFzDSNs6YscAxxr9TyasmRCr0/KK10oz7UWRmrcBH2Cpu0JP3XWMk CNK9VpZ/2LLYIkme5p9d2dOGzYqwX0eCY+kEVrSzJ06WINYh1ctDeB+NxuD3iHSH2nVb tQoMgTJZi0PP97Offi9Q2I7Ex0+WY4BYDh9v7un/SjI6xog87ZJQi1jQqUZJphbyMqcj jiSKmmr8OZsYNDrES1BADoa+jTli+fZrDQnTRhLiA3KIknn2a99KVWLZPHCRU2HIsTCP k+hA== X-Forwarded-Encrypted: i=1; AJvYcCVwlgavf7H/tRzcxYGvzlBmGQ6MAaXvKscF/nUVmmSyhqq6cwMbgrItRx766w7OcLX+sJPiKbCh3/4yfuU=@vger.kernel.org X-Gm-Message-State: AOJu0Yyz0eeQoQVn9md3UVLY3zvm0KxJGoM1vQ2EUwJfs4AwtbWsiDeM cztz2KRUzFOK/6picuonVXPeTIC0s7vqgq5uq78wzUUDyGIGcxrZJjSc5+Ol+5I= X-Gm-Gg: ASbGncuT0y+F3emoyzPoWNnTY8xs166YFGg+qYffXgMcyOwy7p3lclsu6v3hVliRkrR ykp1yz06hsSa1Rz89eLAMjbpojSureVwIzf63CqK5+4cgnvyqqW/V4D2rbP/Oc6zI1EJ1CW00j/ 17KFOey44hTlozrQdxZ37wPHV4DmNJ4/hYKS29IKBj9svhIXLasGQ4Z665dgnhbNdoWMuc+ei2s 6g1IC5Hu1HkiedhjVokw1xgLY7oX3Bs18lpGB88cUiDYGAo4NLrk02vkaM2FTaJ/QyEbwTR0KSh +HeSLJ822akXd3xhqg== X-Google-Smtp-Source: AGHT+IHquCmS/Ws+N8ETp6qk1W23JXufqv87KorQqO19dV0bfSzpED9DtUd1td8zYliKuvNKqQEfZw== X-Received: by 2002:a17:906:110c:b0:ab7:c3c9:2ab1 with SMTP id a640c23a62f3a-ab7c3c92cd1mr379092866b.50.1739200378588; Mon, 10 Feb 2025 07:12:58 -0800 (PST) Received: from blackdock.suse.cz ([193.86.92.181]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ab773339e82sm895192866b.143.2025.02.10.07.12.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Feb 2025 07:12:58 -0800 (PST) From: =?UTF-8?q?Michal=20Koutn=C3=BD?= To: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Frederic Weisbecker Subject: [PATCH 6/9] sched: Bypass bandwitdh checks with runtime disabled RT_GROUP_SCHED Date: Mon, 10 Feb 2025 16:12:36 +0100 Message-ID: <20250210151239.50055-7-mkoutny@suse.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250210151239.50055-1-mkoutny@suse.com> References: <20250210151239.50055-1-mkoutny@suse.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable When RT_GROUPs are compiled but not exposed, their bandwidth cannot be configured (and it is not initialized for non-root task_groups neither). Therefore bypass any checks of task vs task_group bandwidth. This will achieve behavior very similar to setups that have !CONFIG_RT_GROUP_SCHED and attach cpu controller to cgroup v2 hierarchy. (On a related note, this may allow having RT tasks with CONFIG_RT_GROUP_SCHED and cgroup v2 hierarchy.) Signed-off-by: Michal Koutn=C3=BD --- kernel/sched/core.c | 6 +++++- kernel/sched/rt.c | 2 +- kernel/sched/syscalls.c | 3 ++- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5b67b4704a5ed..a418e7bc6a123 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9166,11 +9166,15 @@ static int cpu_cgroup_can_attach(struct cgroup_task= set *tset) struct task_struct *task; struct cgroup_subsys_state *css; =20 + if (!rt_group_sched_enabled()) + goto scx_check; + cgroup_taskset_for_each(task, css, tset) { if (!sched_rt_can_attach(css_tg(css), task)) return -EINVAL; } -#endif +scx_check: +#endif /* CONFIG_RT_GROUP_SCHED */ return scx_cgroup_can_attach(tset); } =20 diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index a427c3f560b71..f25fe2862a7df 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2866,7 +2866,7 @@ static int sched_rt_global_constraints(void) int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) { /* Don't accept real-time tasks when there is no way for them to run */ - if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime =3D=3D 0) + if (rt_group_sched_enabled() && rt_task(tsk) && tg->rt_bandwidth.rt_runti= me =3D=3D 0) return 0; =20 return 1; diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index 8629a87628ebf..7b1689af9ff1e 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -634,7 +634,8 @@ int __sched_setscheduler(struct task_struct *p, * Do not allow real-time tasks into groups that have no runtime * assigned. */ - if (rt_bandwidth_enabled() && rt_policy(policy) && + if (rt_group_sched_enabled() && + rt_bandwidth_enabled() && rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime =3D=3D 0 && !task_group_is_autogroup(task_group(p))) { retval =3D -EPERM; --=20 2.48.1