From patchwork Tue Jan 14 20:41:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Celeste Liu X-Patchwork-Id: 13939507 Received: from fout-b6-smtp.messagingengine.com (fout-b6-smtp.messagingengine.com [202.12.124.149]) (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 B27051459FD; Tue, 14 Jan 2025 20:42:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.149 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887322; cv=none; b=PgcFn4sbymovRGJIeVEDVpiu9a/XYgQfmYnGu5X4POQNtyCIlUK/gO+1SuryEuZiSNCKKJBCRs3zktQhfikOUdlxo1sMhQZ1oZCthfvAl/lPeoIMl6ohV7JYHTcAaki9n2aepBCY7jqf6p5fLO6fz9z39EuQpu2nErBuQjoecV8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887322; c=relaxed/simple; bh=cv3jA4lBt73juQxv0ekC6L4lkRU8HB1MI/gw7T+FRhc=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=OOZ2yso/gf/57N+e/U76xVGk/C1NfTNLnVr7/r9yUjCdgu2G/lBG0dBQEnZzTjpQ4SagwbA5PN+PPkoebGzPCeU5f/sQ7X49J6pvWV7stGrGaLsAqu3RHSKEeb1o3xQlnPXxKjwE6g0sywvX2GD4YBTIGrN7JlI4kbwDNADk9go= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=coelacanthus.name; spf=pass smtp.mailfrom=coelacanthus.name; dkim=pass (2048-bit key) header.d=coelacanthus.name header.i=@coelacanthus.name header.b=Teqv9Aqn; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=tf2j1Nh0; arc=none smtp.client-ip=202.12.124.149 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=coelacanthus.name Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=coelacanthus.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=coelacanthus.name header.i=@coelacanthus.name header.b="Teqv9Aqn"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="tf2j1Nh0" Received: from phl-compute-04.internal (phl-compute-04.phl.internal [10.202.2.44]) by mailfout.stl.internal (Postfix) with ESMTP id EB5D911400D1; Tue, 14 Jan 2025 15:41:58 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-04.internal (MEProxy); Tue, 14 Jan 2025 15:41:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= coelacanthus.name; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:from:from:in-reply-to :message-id:mime-version:reply-to:subject:subject:to:to; s=fm3; t=1736887318; x=1736973718; bh=x6wdS63I7iHxelb/E+SvOq6HbYS9Fkar ZVemmOHTtbY=; b=Teqv9AqnoHU2b/ZfHDmcu3QdSaoJxH8ugHPqnbyxIMBShcwv Lf2GEsXZukuS9aUclO3QhWHoKvIzbcij/syxWl/4aQI0ZhpNHWXobLO5hcW5ShK9 rVBWetAzpiHUUjUJoJuYWIMiTL/WY3l7LkgmZiTge+glzhlm89d/ygR/afLsnG7u SZIkx818drjhQOczxXPZRNjaunM5awjv2mwbxXjwBZp1CKFSF19tv6oHQnPmFRnu g4kWaBM0wy4tq7jyIY29KeVOLG8JPH5Nbz99b10I8yYvmhF7D62o6orTByR1ScZS Tba54HlxHnD+bqVmKjgr+OYMELe8rlbc+aTwVw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:message-id:mime-version:reply-to:subject :subject:to:to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; t=1736887318; x=1736973718; bh=x6wdS63I7iHxelb/E+SvOq6HbYS9 FkarZVemmOHTtbY=; b=tf2j1Nh0libscBgGxLeSHwVa4wSGqR3zyUOhelkXgYpn AM/zuLgmrSrQKhQ38X5yQz6/NXCTaKSFf/BuclcebU4us1a42zc4VSJ10ag2JF7r WK4YtF36eJyQH04oHPWkB4LfhhKOAjcYkEcjEzH9JT1iOszYi/b0/NeJOzDMZQKN EID4mYT2SW0ku4m6Lh/BwUGrjjiVI/wVFG7HR0aFaFcI4yLF83nTFooAAR+NO5yQ Gb7cX4mos/IHAOxzB13/ODi2QQdtsI5Fu5vYj3I4Gm39OIlXFxeXg6meYqJji4gB jPLwrgkICd/ju68HrS4i3QsyNIbniILAm3X+178SXg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrudehiedgudefkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpefhufffkfggtgfgvfevofesthejredtredtjeen ucfhrhhomhepvegvlhgvshhtvgcunfhiuhcuoehufihusegtohgvlhgrtggrnhhthhhush drnhgrmhgvqeenucggtffrrghtthgvrhhnpeefffevkeegffejheejfeefudehffdvleef gfelkeehgffgueejffektefhgeefvdenucffohhmrghinheprhgvughhrghtrdgtohhmpd hgihhthhhusgdrtghomhdpkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrhfuihiivgep tdenucfrrghrrghmpehmrghilhhfrhhomhepuhifuhestghovghlrggtrghnthhhuhhsrd hnrghmvgdpnhgspghrtghpthhtohepfeejpdhmohguvgepshhmthhpohhuthdprhgtphht thhopehglhgruhgsihhtiiesphhhhihsihhkrdhfuhdqsggvrhhlihhnrdguvgdprhgtph htthhopehufihusegtohgvlhgrtggrnhhthhhushdrnhgrmhgvpdhrtghpthhtohepjhho nhgrthhhrghnhhesnhhvihguihgrrdgtohhmpdhrtghpthhtohepfhhlohhrihgrnhdrfh grihhnvghllhhisegsrhhorggutghomhdrtghomhdprhgtphhtthhopehhvghinhhrihgt hhdrshgthhhutghhrghrughtsegtrghnohhnihgtrghlrdgtohhmpdhrtghpthhtohepth honhihsegrthhomhhiuggvrdgtohhmpdhrtghpthhtoheplhhinhhugidqrhhishgtvhes lhhishhtshdrihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopehtrhgvughinhhgse hnvhhiughirgdrtghomhdprhgtphhtthhopegrnhhuphessghrrghinhhfrghulhhtrdho rhhg X-ME-Proxy: Feedback-ID: i95c648bc:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 14 Jan 2025 15:41:54 -0500 (EST) From: Celeste Liu Subject: [PATCH v4 0/4] defconfig: drop RT_GROUP_SCHED=y Date: Wed, 15 Jan 2025 04:41:19 +0800 Message-Id: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> Precedence: bulk X-Mailing-List: linux-sh@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAO/LhmcC/33OTWrDMBAF4KsErTtBksc/6arQTe8QSlCksSWIr TByRELw3Suni2TTbgYezPt4d5GIAyXxvrkLphxSiFMJ+LYR1ptpIAiuZKGlRtnoFvpwBQ7JZuD 5MHC8nA/JenLgNEmFR8LOGVHqZ6by+6D33yX3HEeYPZN5gnUllVI7bLc1lovQwWekk7Fmmv0lf dH1YxhNOG1tHFfThzRHvj3WZr3Kv06nq7+HZQ0SCN3RkMa+JfVirsNy9YR2Sv4DVQXCrqG2ptp Q416hZVl+ALc/HAZNAQAA X-Change-ID: 20240627-fix-riscv-rt_group_sched-d2e014be48da To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , Anup Patel , Heinrich Schuchardt , Huacai Chen , WANG Xuerui , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , Russell King , Florian Fainelli , Broadcom internal kernel review list , Ray Jui , Scott Branden , Tony Lindgren , Thierry Reding , Jonathan Hunter , Aaro Koskinen , Andreas Kemnade , Kevin Hilman , Roger Quadros Cc: Palmer Dabbelt , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-sh@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org, Charlie Jenkins , Celeste Liu , Xi Ruoyao , Stefan Wahren , Thierry Reding X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2984; i=uwu@coelacanthus.name; h=from:subject:message-id; bh=cv3jA4lBt73juQxv0ekC6L4lkRU8HB1MI/gw7T+FRhc=; b=owJ4nJvAy8zAJeafov85RWVtBeNptSSG9LYzrF3Z/pe2qQhcyZn/MCV2WlTgnZb9bI6XGWaqv NWMu1li9KSjlIVBjItBVkyRJa+E5SfnpbPdezu2d8HMYWUCGcLAxSkAE2mMYPhnf5ezRCRmNU9M 8yb9HuNZh25tn7bKI/6ll/Gjnh18LKWmjAwHNHVXXoyo5D/R+kHNU/Jo6GH+5VxvjMNnC54TvJi 4v5EdAFPWRmA= X-Developer-Key: i=uwu@coelacanthus.name; a=openpgp; fpr=892EBC7DC392DFF9C9C03F1D15F4180E73787863 For cgroup v1, if turned on, and there's any cgroup in the "cpu" hierarchy it needs an RT budget assigned, otherwise the processes in it will not be able to get RT at all. The problem with RT group scheduling is that it requires the budget assigned but there's no way we could assign a default budget, since the values to assign are both upper and lower time limits, are absolute, and need to be sum up to < 1 for each individal cgroup. That means we cannot really come up with values that would work by default in the general case.[1] For cgroup v2, it's almost unusable as well. If it turned on, the cpu controller can only be enabled when all RT processes are in the root cgroup. But it will lose the benefits of cgroup v2 if all RT process were placed in the same cgroup. Red Hat, Gentoo, Arch Linux and Debian all disable it. systemd also doesn't support it.[2] [1]: https://bugzilla.redhat.com/show_bug.cgi?id=1229700 [2]: https://github.com/systemd/systemd/issues/13781#issuecomment-549164383 --- Changes in v4: - Update Acked-by - Link to v3: https://lore.kernel.org/r/20240910-fix-riscv-rt_group_sched-v3-0-486e75e5ae6d@gmail.com Changes in v3: - Remove Fixes: tag because of it's not suitable. - Link to v2: https://lore.kernel.org/r/20240823-fix-riscv-rt_group_sched-v2-0-e4dbae24f7e1@gmail.com Changes in v2: * Remove MIPS and PowerPC patch because of merged. * Link to v1: https://lore.kernel.org/lkml/20240530111947.549474-8-CoelacanthusHex@gmail.com/T Celeste Liu (6): riscv: defconfig: drop RT_GROUP_SCHED=y loongarch: defconfig: drop RT_GROUP_SCHED=y sh: defconfig: drop RT_GROUP_SCHED=y from sdk7786/urquell arm: defconfig: drop RT_GROUP_SCHED=y from bcm2855/tegra/omap2plus arch/arm/configs/bcm2835_defconfig | 1 - arch/arm/configs/omap2plus_defconfig | 1 - arch/arm/configs/tegra_defconfig | 1 - arch/loongarch/configs/loongson3_defconfig | 1 - arch/riscv/configs/defconfig | 1 - arch/sh/configs/sdk7786_defconfig | 1 - arch/sh/configs/urquell_defconfig | 1 - 7 files changed, 7 deletions(-) -- 2.45.1 --- Celeste Liu (4): riscv: defconfig: drop RT_GROUP_SCHED=y loongarch: defconfig: drop RT_GROUP_SCHED=y sh: defconfig: drop RT_GROUP_SCHED=y from sdk7786/urquell arm: defconfig: drop RT_GROUP_SCHED=y from bcm2835/tegra/omap2plus arch/arm/configs/bcm2835_defconfig | 1 - arch/arm/configs/omap2plus_defconfig | 1 - arch/arm/configs/tegra_defconfig | 1 - arch/loongarch/configs/loongson3_defconfig | 1 - arch/riscv/configs/defconfig | 1 - arch/sh/configs/sdk7786_defconfig | 1 - arch/sh/configs/urquell_defconfig | 1 - 7 files changed, 7 deletions(-) --- base-commit: 0e287d31b62bb53ad81d5e59778384a40f8b6f56 change-id: 20240627-fix-riscv-rt_group_sched-d2e014be48da Best regards,