From patchwork Tue Jan 14 20:41:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Celeste Liu X-Patchwork-Id: 13939503 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 6C48220E005; Tue, 14 Jan 2025 20:42:06 +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=1736887328; cv=none; b=T4y9FVm2iOsd2cHJGrVIu5DrZF7CEoOeLo756sTqWdtDyYTakCvp0xBHpYajM1XG+HERPPGRZnkiZDoW3qz7tVHTVKq8rPiiGju5f24svEw6fiYTjIT2aQc7ZhKa9dUoG5QOqyns0j5iEsFuGdekWDa+h/EOp/I4h3DefceiMTM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887328; c=relaxed/simple; bh=WkvIObUchYpAilmJK89a2+ds4ehlRbbV+Uqcck4hmYI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qFlvdutAbOPTQKmayrDAkSpEx+oyhYMDM+I3CkAI4aWOUnthXSZdlGhR3clxpGufeqPot86I+JWOzi9wBR7acIAIksIw6/9+gBFuu5cn+/PtzVyljQ4LfOMS1ygnnq5uFAvFEFx7sX9LxytIx6p6fv0dHvyr63Qr1qdlj2JpeWw= 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=YH57aj+O; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=UdI02B+9; 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="YH57aj+O"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="UdI02B+9" Received: from phl-compute-06.internal (phl-compute-06.phl.internal [10.202.2.46]) by mailfout.stl.internal (Postfix) with ESMTP id D475411400CB; Tue, 14 Jan 2025 15:42:04 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-06.internal (MEProxy); Tue, 14 Jan 2025 15:42:05 -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 :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm3; t=1736887324; x=1736973724; bh=G+TEiYNlY0 62v675yUdgWXwYQfH2PLhBA2LiyUaadgQ=; b=YH57aj+O9WFA8KiXGhA56PD/El vs4vYkqg7DqvUCa4QySoCLF6fJKn5ea+yGjGIrt1kWUs6z4buWBIpDmlZr1Bdbxb Ub5DxUiheG/vg0ALwk0RGxm3aLc3xwJirIwg+MEq9IYCsGeNMw0r9PWNCVivNCu/ ZS/zo2g8pha4mSOj/5zdFLRsqDCoCAK0jaRtcvhJd+LRDe/5pOVq2h5/vdtdcDAl jQ8AMClnfWTAaHjaV5HqLwVadK1ptSb+199bFbRw0+h3CeRJhmX2Sl90V9dp/To1 2YssGh8+PguoDlSnkFKQh03gMyYOAmWbLKF8HhUbfqAfW+tQRyHLsItQJACw== 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:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1736887324; x= 1736973724; bh=G+TEiYNlY062v675yUdgWXwYQfH2PLhBA2LiyUaadgQ=; b=U dI02B+9OgXBAO8VPZlBm+qO13y2UuJ5WxSOIw/vUR3XD6JD9YMopBUKGSmJ1BR13 jY1uISp4uhco6wQlC2rXiSb9qGe1ge5c+FZN/+uhWHiHIjKj4KDEwC916ZSGZX1r SCfot0KxGRu6Ux+0hgbx9CLeAivvthda5nnYnp1E07v2wczK78+3DNM/rqj1Yg67 pIadtl3ul7QNq9p/Zs9STu0psK0LzFM5ShleTLcV84xt/6xunCHmra0NfgeNOxA4 FqyBHslHpEYBHxqW8kzIbmdkBf1lQbVE9eEDSOi8Es3L8iu5Jgff+b6FlREC9d9r r6cmdEbBTH7PXRnKnyNvQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrudehiedgudeflecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredt jeenucfhrhhomhepvegvlhgvshhtvgcunfhiuhcuoehufihusegtohgvlhgrtggrnhhthh hushdrnhgrmhgvqeenucggtffrrghtthgvrhhnpeegfeekfeelteeufeekleeukeegffef keetveffffethfevheevjeektdelueegteenucffohhmrghinhepghhithhhuhgsrdgtoh hmpdhrvgguhhgrthdrtghomhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhep mhgrihhlfhhrohhmpehufihusegtohgvlhgrtggrnhhthhhushdrnhgrmhgvpdhnsggprh gtphhtthhopeefgedpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepghhlrghusghi thiisehphhihshhikhdrfhhuqdgsvghrlhhinhdruggvpdhrtghpthhtohepuhifuhestg hovghlrggtrghnthhhuhhsrdhnrghmvgdprhgtphhtthhopehjohhnrghthhgrnhhhsehn vhhiughirgdrtghomhdprhgtphhtthhopehflhhorhhirghnrdhfrghinhgvlhhlihessg hrohgruggtohhmrdgtohhmpdhrtghpthhtohephhgvihhnrhhitghhrdhstghhuhgthhgr rhguthestggrnhhonhhitggrlhdrtghomhdprhgtphhtthhopehtohhnhiesrghtohhmih guvgdrtghomhdprhgtphhtthhopehlihhnuhigqdhrihhstghvsehlihhsthhsrdhinhhf rhgruggvrggurdhorhhgpdhrtghpthhtoheprghnuhhpsegsrhgrihhnfhgruhhlthdroh hrghdprhgtphhtthhopegthhgvnhhhuhgrtggriheskhgvrhhnvghlrdhorhhg X-ME-Proxy: Feedback-ID: i95c648bc:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 14 Jan 2025 15:42:02 -0500 (EST) From: Celeste Liu Date: Wed, 15 Jan 2025 04:41:20 +0800 Subject: [PATCH v4 1/4] riscv: defconfig: drop RT_GROUP_SCHED=y Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fix-riscv-rt_group_sched-v4-1-607606fe73a5@coelacanthus.name> References: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> In-Reply-To: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> 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 X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1987; i=uwu@coelacanthus.name; h=from:subject:message-id; bh=WkvIObUchYpAilmJK89a2+ds4ehlRbbV+Uqcck4hmYI=; b=owJ4nJvAy8zAJeafov85RWVtBeNptSSG9LYz7JZzu3m/esxYasXrc/3aJMUnP55MOzQjsTiBq Seg9WqipkpHKQuDGBeDrJgiS14Jy0/OS2e793Zs74KZw8oEMoSBi1MAJpLfz/BXtuPp5Qf6PQtd TGe9Tzi5LWZZ3vVca522z6+Y+d6kPv8RyMjw+ofpP9fk2b+37mTferiEddNnkwnxn94lXNFfr20 fd2kKMwBcoU0m X-Developer-Key: i=uwu@coelacanthus.name; a=openpgp; fpr=892EBC7DC392DFF9C9C03F1D15F4180E73787863 Commit ba6cfef057e1 ("riscv: enable Docker requirements in defconfig") introduced it because of Docker, but Docker has removed this requirement since [1] (2023-04-19). 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.[2] 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.[3] [1]: https://github.com/moby/moby/commit/005150ed69c540fb0b5323e0f2208608c1204536 [2]: https://bugzilla.redhat.com/show_bug.cgi?id=1229700 [3]: https://github.com/systemd/systemd/issues/13781#issuecomment-549164383 Acked-by: Heinrich Schuchardt Acked-by: Charlie Jenkins Signed-off-by: Celeste Liu --- arch/riscv/configs/defconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig index b4a37345703eb35757419aa5a2b057c82ed22fda..46b8fb30726858a945a24097773174961c2f4d10 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -10,7 +10,6 @@ CONFIG_MEMCG=y CONFIG_BLK_CGROUP=y CONFIG_CGROUP_SCHED=y CONFIG_CFS_BANDWIDTH=y -CONFIG_RT_GROUP_SCHED=y CONFIG_CGROUP_PIDS=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_HUGETLB=y From patchwork Tue Jan 14 20:41:21 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Celeste Liu X-Patchwork-Id: 13939504 Received: from fhigh-b5-smtp.messagingengine.com (fhigh-b5-smtp.messagingengine.com [202.12.124.156]) (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 E49F220CCEB; Tue, 14 Jan 2025 20:42:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.156 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887334; cv=none; b=el4cR2rkflJtK9bI3UFf26aEllOqRv4M1oSb4+QUDm48sIpQguzr5UFuGI+RHrdX0GUqS8zEJDd0fn/Di4uRM4nwCC/SWaghk46BEEyopvca0SRcqY/322JLD6il8NMMZ8Z5mdaKAgXvovtTanAg0pedE1ueLd7qphU4lwThEJI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887334; c=relaxed/simple; bh=faYQjbUe+IZ6IbLVoFWLES94wJ4yKdbIyLHK1P3reTU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=iUukpBKixbBq/92Q2NbtMpaW39QCBOh2CwOq9c1go1/L+4WW19OciOve+jZsEQQLoTNVz2436NNwL6VWyioQ1sEiHKMw6evAsncs4v4jVJ1IujsYHGQMqex2LnhUReXL0fGjL+aXYahcraIU9VUUCLrlCvp8+fHrejnwyAxVzdU= 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=IAKGZc3a; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=IiUpBfIS; arc=none smtp.client-ip=202.12.124.156 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="IAKGZc3a"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="IiUpBfIS" Received: from phl-compute-02.internal (phl-compute-02.phl.internal [10.202.2.42]) by mailfhigh.stl.internal (Postfix) with ESMTP id 3E80D25400FF; Tue, 14 Jan 2025 15:42:11 -0500 (EST) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-02.internal (MEProxy); Tue, 14 Jan 2025 15:42:12 -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 :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm3; t=1736887331; x=1736973731; bh=SoZljfqV8Y 76xmxQUUDqkab4/v2p6BHdmrbK5iG/0+g=; b=IAKGZc3athbt3hkSGEEWqMY7ze mRmr7xsvi+z5vfd4Dyr0vRzQ2GGlYCcw84PUlMvxW8DaNNmw3wBRor1f0F53qaQd tHeAPBUuBZcY6Y6STHHI/kGkIAgzqTorwThm7bTMErrdXttKRKmafSTbyk/nl6py FBoaTwMT584P+XAj9Q5jdiiaRhcVU1i18N4MMf+sh1G68koVQop8MIe7fhJe9MEk OzlMBI2QDety9Jrwp17pPArOswDD6duSaRN2bzUVOima8JIx7fjsbH5mVT8vQCeX dB8cW7+ZHZIqPoxRL8CZshzdpehthwupK+h67nIAag0mRbyhtW8PWsuTosGQ== 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:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1736887331; x= 1736973731; bh=SoZljfqV8Y76xmxQUUDqkab4/v2p6BHdmrbK5iG/0+g=; b=I iUpBfISPzKBT9yT6zKuwlNp0GG58m7pSzuKPBqLqZajDBABVXrnH5Ej7rfNVibxS pTdzrR0R0sdoKDWOiNUXhAq9KWKByoCFXzsp9+y9lQ/zIqsZoeNQ7nCesgLzfjba DdzMIThDLkz5tzQzl2M0TqL/SVBVLCG5EmqDC9XdOhD7YgnMeSVA4MecxFIyP3md 5sHqSjtVuO+22UKXeUlmSTU2R1MwetSUHCLv6A/dWNrZGQQT3BRsFrBcOGMn7i5/ +0/vM1GFLMlc7rGJ0G4J5WxgFAIfCPWOp+Ya9pkHS5R3ZpjUFoJVi/hXD7ypKipx lfQbCq/pVe2nDY9sO9DSQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrudehiedgudefkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredt jeenucfhrhhomhepvegvlhgvshhtvgcunfhiuhcuoehufihusegtohgvlhgrtggrnhhthh hushdrnhgrmhgvqeenucggtffrrghtthgvrhhnpefgkefhjeeiueekgfffuedvheegffdt hffghfetveejtdetffeugeejkeduieehveenucffohhmrghinheprhgvughhrghtrdgtoh hmpdhgihhthhhusgdrtghomhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhep mhgrihhlfhhrohhmpehufihusegtohgvlhgrtggrnhhthhhushdrnhgrmhgvpdhnsggprh gtphhtthhopeefgedpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepghhlrghusghi thiisehphhihshhikhdrfhhuqdgsvghrlhhinhdruggvpdhrtghpthhtohepuhifuhestg hovghlrggtrghnthhhuhhsrdhnrghmvgdprhgtphhtthhopehjohhnrghthhgrnhhhsehn vhhiughirgdrtghomhdprhgtphhtthhopehflhhorhhirghnrdhfrghinhgvlhhlihessg hrohgruggtohhmrdgtohhmpdhrtghpthhtohephhgvihhnrhhitghhrdhstghhuhgthhgr rhguthestggrnhhonhhitggrlhdrtghomhdprhgtphhtthhopehtohhnhiesrghtohhmih guvgdrtghomhdprhgtphhtthhopehlihhnuhigqdhrihhstghvsehlihhsthhsrdhinhhf rhgruggvrggurdhorhhgpdhrtghpthhtoheprghnuhhpsegsrhgrihhnfhgruhhlthdroh hrghdprhgtphhtthhopegthhgvnhhhuhgrtggriheskhgvrhhnvghlrdhorhhg X-ME-Proxy: Feedback-ID: i95c648bc:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 14 Jan 2025 15:42:09 -0500 (EST) From: Celeste Liu Date: Wed, 15 Jan 2025 04:41:21 +0800 Subject: [PATCH v4 2/4] loongarch: defconfig: drop RT_GROUP_SCHED=y Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fix-riscv-rt_group_sched-v4-2-607606fe73a5@coelacanthus.name> References: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> In-Reply-To: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> 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, Xi Ruoyao , Celeste Liu X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1728; i=uwu@coelacanthus.name; h=from:subject:message-id; bh=faYQjbUe+IZ6IbLVoFWLES94wJ4yKdbIyLHK1P3reTU=; b=owJ4nJvAy8zAJeafov85RWVtBeNptSSG9LYzHNpGz3RdNkcq+138urdnco6HmLJOMKeQx8/dB x+9M/n57GhHKQuDGBeDrJgiS14Jy0/OS2e793Zs74KZw8oEMoSBi1MAJnIth5HhTFFkrOksz5Be jqCyI7OyWK2EubUnagjfyV8kYSe7ROMtw3+f+83SDSq+R6Y+//vmimFTUov/35ffOJ3jLvsv+PF vwT8+AA0oSNQ= 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 Reviewed-by: Xi Ruoyao Signed-off-by: Celeste Liu --- arch/loongarch/configs/loongson3_defconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index 4dffc90192f7816074c3bd4b55c12159d5757676..4387bcec8f484173e5367456a69f6a7f03595d46 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -24,7 +24,6 @@ CONFIG_NUMA_BALANCING=y CONFIG_MEMCG=y CONFIG_BLK_CGROUP=y CONFIG_CFS_BANDWIDTH=y -CONFIG_RT_GROUP_SCHED=y CONFIG_CGROUP_PIDS=y CONFIG_CGROUP_RDMA=y CONFIG_CGROUP_FREEZER=y From patchwork Tue Jan 14 20:41:22 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Celeste Liu X-Patchwork-Id: 13939505 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 8148F212B34; Tue, 14 Jan 2025 20:42:18 +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=1736887340; cv=none; b=tg5ITLsRI3nDPyjJY6LxLgDyuqqf4s91gm43sYlxhrBjNEAkv91KOA9p7DWYgCLOl/HzqAtWZoy/FA8QxczgJwODn+Ry0SSWIViwonPFJzH0CCshwui8EohwQCygSJxcdF9mZn4xWhT5CVGYxlhI2CH2Qz/s3XxomU5MbsbKS2k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887340; c=relaxed/simple; bh=BhZXBD4LrwRi3kBTuqWLXE3VKHJ0GCDQScQEjxdA+cU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=JPPBXZmD7XzL+sIRd806b+C6nXA8MwoQqIbsSvrnsSceCWFFHFPYoM/QG8KDB+GRLno5PCyMIQzvgFngbQVDwErWKSKxF+8jqi6ubZLjYhCNW+9zMPeVR+MQnr4QaGlfMt0PtBb287P0Jp5zTWD+y9pU0HOurQEJRRxiGrIJ+zg= 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=L8UK+qNt; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=Tj/+nmxT; 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="L8UK+qNt"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="Tj/+nmxT" Received: from phl-compute-12.internal (phl-compute-12.phl.internal [10.202.2.52]) by mailfout.stl.internal (Postfix) with ESMTP id D7F9611400D1; Tue, 14 Jan 2025 15:42:16 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-12.internal (MEProxy); Tue, 14 Jan 2025 15:42:17 -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 :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm3; t=1736887336; x=1736973736; bh=l/AGE8pJh7 GgNRDEtM0gaQGj3X0ZPhDFL8vEdG1DJNQ=; b=L8UK+qNtsmAFZQ+3hTNYAXZIpB Qr13KJDajs03XLtUJ5I+ZEH0mOVmXZ3rsNRiNEWx+547dJ8K30+6aOuZYIoPAofL VXNFcJEUV/fPhXRue16Yqgb+VhoM8VJXH3JovgIFMPL0Mg6euHE6Pog9n8jt8Vtm DO1sLrPvlNBFeXEWZ5HnPzd/ZjjAtQBMRaOfBfS9lNLtG53P3uKB2ur4rXTOKn6X qrdjomrCEeY0zr9E5TB9wNEFjEW3CTWE2fUZWHXlj8SREE9Uhnt9JrJEdR/Yc8DQ 1FXmCuryCrUZTv4NbBmVFP728Vht4AwZ6pcOfuJYckNrpFhpHy2Bz8sBXl+A== 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:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1736887336; x= 1736973736; bh=l/AGE8pJh7GgNRDEtM0gaQGj3X0ZPhDFL8vEdG1DJNQ=; b=T j/+nmxTF/xg51kX7Zt5H8xXFAixMs0vIuoGDDzf0bNzFF6QfwPx+wyhEPb8qBqKk 3YnAbrOPq6rK5uSYl7oCtB6bcPSvYdPf8L8ooOYw4PwkM8WkVhrdo2qElr1ieXIQ hrWUWrbBLyjeqyrqhf6zQVG703aUCfLIrR5yLC/rq7suim71bS5nuB+wLT3KL7En QnhgBBgDLBXugDc4uX2KFSZXk73Slme9IVDBdrj01GJcFy4NtzExpdcR+LnAPZ0r 0ZoQWHyegmG8vP1dXTDxG9kUw/jFQiWJvP4h/MQ10mc2XO5UXIPeeT1W7fJ//EWx gYSxKSBmJzRmxTfMSFyOw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrudehiedgudefkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredt jeenucfhrhhomhepvegvlhgvshhtvgcunfhiuhcuoehufihusegtohgvlhgrtggrnhhthh hushdrnhgrmhgvqeenucggtffrrghtthgvrhhnpefgkefhjeeiueekgfffuedvheegffdt hffghfetveejtdetffeugeejkeduieehveenucffohhmrghinheprhgvughhrghtrdgtoh hmpdhgihhthhhusgdrtghomhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhep mhgrihhlfhhrohhmpehufihusegtohgvlhgrtggrnhhthhhushdrnhgrmhgvpdhnsggprh gtphhtthhopeeffedpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepghhlrghusghi thiisehphhihshhikhdrfhhuqdgsvghrlhhinhdruggvpdhrtghpthhtohepuhifuhestg hovghlrggtrghnthhhuhhsrdhnrghmvgdprhgtphhtthhopehjohhnrghthhgrnhhhsehn vhhiughirgdrtghomhdprhgtphhtthhopehflhhorhhirghnrdhfrghinhgvlhhlihessg hrohgruggtohhmrdgtohhmpdhrtghpthhtohephhgvihhnrhhitghhrdhstghhuhgthhgr rhguthestggrnhhonhhitggrlhdrtghomhdprhgtphhtthhopehtohhnhiesrghtohhmih guvgdrtghomhdprhgtphhtthhopehlihhnuhigqdhrihhstghvsehlihhsthhsrdhinhhf rhgruggvrggurdhorhhgpdhrtghpthhtoheprghnuhhpsegsrhgrihhnfhgruhhlthdroh hrghdprhgtphhtthhopegthhgvnhhhuhgrtggriheskhgvrhhnvghlrdhorhhg X-ME-Proxy: Feedback-ID: i95c648bc:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 14 Jan 2025 15:42:14 -0500 (EST) From: Celeste Liu Date: Wed, 15 Jan 2025 04:41:22 +0800 Subject: [PATCH v4 3/4] sh: defconfig: drop RT_GROUP_SCHED=y from sdk7786/urquell Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fix-riscv-rt_group_sched-v4-3-607606fe73a5@coelacanthus.name> References: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> In-Reply-To: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> 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, Celeste Liu X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2139; i=uwu@coelacanthus.name; h=from:subject:message-id; bh=BhZXBD4LrwRi3kBTuqWLXE3VKHJ0GCDQScQEjxdA+cU=; b=owJ4nJvAy8zAJeafov85RWVtBeNptSSG9LYznD2fd8RwHNpoculb9K0DbSGum9JK0po6eNP3r XvhzbsqR62jlIVBjItBVkyRJa+E5SfnpbPdezu2d8HMYWUCGcLAxSkAE4mXYPjFdGNfLecKz3NZ c/l+va5WTKo7y3prwpVfJ46wr578m4stjOGf0c+3AjpK3ydda3l2lrmxVG7ynlsv1Z/xT9xxwKV oxbfTPACIpk1T 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 Signed-off-by: Celeste Liu --- arch/sh/configs/sdk7786_defconfig | 1 - arch/sh/configs/urquell_defconfig | 1 - 2 files changed, 2 deletions(-) diff --git a/arch/sh/configs/sdk7786_defconfig b/arch/sh/configs/sdk7786_defconfig index 07894f13441ef622c3af8d8f4b5770c2ab66bcd8..7a6efd5b4a62463381005072a679a8ce022a2ef9 100644 --- a/arch/sh/configs/sdk7786_defconfig +++ b/arch/sh/configs/sdk7786_defconfig @@ -17,7 +17,6 @@ CONFIG_CPUSETS=y CONFIG_CGROUP_CPUACCT=y CONFIG_CGROUP_MEMCG=y CONFIG_CGROUP_SCHED=y -CONFIG_RT_GROUP_SCHED=y CONFIG_BLK_CGROUP=y CONFIG_RELAY=y CONFIG_NAMESPACES=y diff --git a/arch/sh/configs/urquell_defconfig b/arch/sh/configs/urquell_defconfig index 00ef62133b04ded8d0b4221f11e0adafde99d386..9cf4a719001ea5ef4b031c1bbbf8098e8af5a2b2 100644 --- a/arch/sh/configs/urquell_defconfig +++ b/arch/sh/configs/urquell_defconfig @@ -15,7 +15,6 @@ CONFIG_CPUSETS=y CONFIG_CGROUP_CPUACCT=y CONFIG_CGROUP_MEMCG=y CONFIG_CGROUP_SCHED=y -CONFIG_RT_GROUP_SCHED=y CONFIG_BLK_DEV_INITRD=y CONFIG_PROFILING=y CONFIG_MODULES=y From patchwork Tue Jan 14 20:41:23 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Celeste Liu X-Patchwork-Id: 13939506 Received: from fhigh-b5-smtp.messagingengine.com (fhigh-b5-smtp.messagingengine.com [202.12.124.156]) (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 87A2C20DD79; Tue, 14 Jan 2025 20:42:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.156 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887346; cv=none; b=XpXWOn6WqlYdOhqVpYpnXKEBIHnUCzi1Ajd4ax8lQbA1eP5ckodNMXXqAmqVd44ui/U9bRUcodKQujudIVMGiGBHhpKxdEtDx6jI0LkqtYz/5ScMId733DB5cRFgwsrSg0HQmjc0M2YA1qpDF0GdNx7vYDlk712xRcOMVKhfwwU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736887346; c=relaxed/simple; bh=FD1/1Qa4M60bWS/VL5WGmaGZ5+Z9xkiSLJsG1Uy3KWw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=sMP9bVqz0FysUC/FS0cPLm6K2Yfk3neUGWel1yGMPsBlCJ8vqLT4kz1FQeG3rOaJJiBGPeJExwAgnD26E2m0Chd4v8r+OOHw9WhFZzw0vHw4Ic5J4IheoUc0XtkivBhpl2np3h+Qso98wUEmebPoFLWNFciP6Tkk5eIMiaL97s4= 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=QZ6xuLkN; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=a8OTIr7E; arc=none smtp.client-ip=202.12.124.156 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="QZ6xuLkN"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="a8OTIr7E" Received: from phl-compute-02.internal (phl-compute-02.phl.internal [10.202.2.42]) by mailfhigh.stl.internal (Postfix) with ESMTP id E302325400D3; Tue, 14 Jan 2025 15:42:21 -0500 (EST) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-02.internal (MEProxy); Tue, 14 Jan 2025 15:42:22 -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 :in-reply-to:message-id:mime-version:references:reply-to:subject :subject:to:to; s=fm3; t=1736887341; x=1736973741; bh=0iZWF2p7Dd Tt4UZs/drcsgp85LST9ju/nBZkrLmrFzQ=; b=QZ6xuLkN5pAT1+cm6wn4ZjfgK3 UcJKqYc//8mwUoEKYybP4yc3M0ybRXdRyzfZE9EdygfzSlmC9XERU531YCz/jtVR bJnjScooSlL+FEnTpuyc4AqUISgDLwxfF3fkMhSM8e6Df4hwNPg4YFx2lcjrhoMA MHwgG0gGf5BQWFQ/PqdjoUb+ZlEbYZ2j1x4HV392HkT6xG764FjdBfULRFPHcUjA jV+x0iXjY8LCQxBxM7dGeC1qRu1/+hMZVKYqw9EAgDMHIp7+Rl1XzfldAQlymh6S FhrnjzSyZ/tD0l5CV9x/euilBRAU3BzJJLiyWOS1lRodC162G6pgo41ipGbQ== 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:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1736887341; x= 1736973741; bh=0iZWF2p7DdTt4UZs/drcsgp85LST9ju/nBZkrLmrFzQ=; b=a 8OTIr7E7G+oQlzNO5rrrZuEG1cg66538u+UhaLh3M7zG3axbN3rD8j4UvpLnY09C H/sHWpt1f1PeucUUU5zFLMf8PZsY2liCwXjWGjHyhzxXkhf10w6ui6sqp/Fk8tWf y6WgNfif6rXUZDJHBhbU1/g0W0ztcrf3ulcTQTRB0fHjy5drfGK0YOPhiag23YrR ewR9kBZE0NAZNu2zTWgl/gIuXNxnNv6ydm6G5bajT0C/Dj3xUQv/3NLpvVoyjU6D 6YOeMsFgq6RsTkacxLS06QQSJNBdFMjIXcFCIK7PdSqOItXG+3c28G482i5eC0eq drroWxZqPJzHfvsyyJ0HQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrudehiedgudefkecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdp uffrtefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivg hnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredt jeenucfhrhhomhepvegvlhgvshhtvgcunfhiuhcuoehufihusegtohgvlhgrtggrnhhthh hushdrnhgrmhgvqeenucggtffrrghtthgvrhhnpeegfeekfeelteeufeekleeukeegffef keetveffffethfevheevjeektdelueegteenucffohhmrghinhepghhithhhuhgsrdgtoh hmpdhrvgguhhgrthdrtghomhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhep mhgrihhlfhhrohhmpehufihusegtohgvlhgrtggrnhhthhhushdrnhgrmhgvpdhnsggprh gtphhtthhopeefhedpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepghhlrghusghi thiisehphhihshhikhdrfhhuqdgsvghrlhhinhdruggvpdhrtghpthhtohepuhifuhestg hovghlrggtrghnthhhuhhsrdhnrghmvgdprhgtphhtthhopehjohhnrghthhgrnhhhsehn vhhiughirgdrtghomhdprhgtphhtthhopehflhhorhhirghnrdhfrghinhgvlhhlihessg hrohgruggtohhmrdgtohhmpdhrtghpthhtohephhgvihhnrhhitghhrdhstghhuhgthhgr rhguthestggrnhhonhhitggrlhdrtghomhdprhgtphhtthhopehtohhnhiesrghtohhmih guvgdrtghomhdprhgtphhtthhopehlihhnuhigqdhrihhstghvsehlihhsthhsrdhinhhf rhgruggvrggurdhorhhgpdhrtghpthhtohepthhrvgguihhnghesnhhvihguihgrrdgtoh hmpdhrtghpthhtoheprghnuhhpsegsrhgrihhnfhgruhhlthdrohhrgh X-ME-Proxy: Feedback-ID: i95c648bc:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 14 Jan 2025 15:42:20 -0500 (EST) From: Celeste Liu Date: Wed, 15 Jan 2025 04:41:23 +0800 Subject: [PATCH v4 4/4] arm: defconfig: drop RT_GROUP_SCHED=y from bcm2835/tegra/omap2plus Precedence: bulk X-Mailing-List: linux-omap@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fix-riscv-rt_group_sched-v4-4-607606fe73a5@coelacanthus.name> References: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> In-Reply-To: <20250115-fix-riscv-rt_group_sched-v4-0-607606fe73a5@coelacanthus.name> 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, Stefan Wahren , Thierry Reding , Celeste Liu X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=3034; i=uwu@coelacanthus.name; h=from:subject:message-id; bh=FD1/1Qa4M60bWS/VL5WGmaGZ5+Z9xkiSLJsG1Uy3KWw=; b=owJ4nJvAy8zAJeafov85RWVtBeNptSSG9LYzXHLFi27K+J2ZHz412+f0Dang54s+PZiXrRvfZ Mzq7eFZld5RysIgxsUgK6bIklfC8pPz0tnuvR3bu2DmsDKBDGHg4hSAiZwKYPgftqP47j7Xd8HJ nxstvriK7bd9n/3oW4KK9qknWza/vBH1hOF/NJsix3WlLcsedN04JFMQH3F0/rRIpYj0J/MeWk4 6tv8qCwAph01E X-Developer-Key: i=uwu@coelacanthus.name; a=openpgp; fpr=892EBC7DC392DFF9C9C03F1D15F4180E73787863 Commit 673ce00c5d6c ("ARM: omap2plus_defconfig: Add support for distros with systemd") said it's because of recommendation from systemd. But systemd changed their recommendation later.[1] 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.[2] 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. [1]: https://github.com/systemd/systemd/commit/f4e74be1856b3ac058acbf1be321c31d5299f69f [2]: https://bugzilla.redhat.com/show_bug.cgi?id=1229700 Tested-by: Stefan Wahren Acked-by: Kevin Hilman Acked-by: Thierry Reding Signed-off-by: Celeste Liu --- arch/arm/configs/bcm2835_defconfig | 1 - arch/arm/configs/omap2plus_defconfig | 1 - arch/arm/configs/tegra_defconfig | 1 - 3 files changed, 3 deletions(-) diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig index b5f0bd8dd536990a0726e73a6855d25c1286a768..27dc3bf6b124c2012b7a1a768f2f900f49903cd1 100644 --- a/arch/arm/configs/bcm2835_defconfig +++ b/arch/arm/configs/bcm2835_defconfig @@ -7,7 +7,6 @@ CONFIG_BSD_PROCESS_ACCT=y CONFIG_BSD_PROCESS_ACCT_V3=y CONFIG_LOG_BUF_SHIFT=18 CONFIG_CFS_BANDWIDTH=y -CONFIG_RT_GROUP_SCHED=y CONFIG_CGROUP_FREEZER=y CONFIG_CPUSETS=y CONFIG_CGROUP_DEVICE=y diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig index 3a166c2f02bd80634fee3bd8c4579fdbad84ccfa..9cb265c8d4144ea9a41f02640dbc8a06b710323b 100644 --- a/arch/arm/configs/omap2plus_defconfig +++ b/arch/arm/configs/omap2plus_defconfig @@ -13,7 +13,6 @@ CONFIG_MEMCG=y CONFIG_BLK_CGROUP=y CONFIG_CGROUP_SCHED=y CONFIG_CFS_BANDWIDTH=y -CONFIG_RT_GROUP_SCHED=y CONFIG_CGROUP_FREEZER=y CONFIG_CPUSETS=y CONFIG_CGROUP_DEVICE=y diff --git a/arch/arm/configs/tegra_defconfig b/arch/arm/configs/tegra_defconfig index d2a094ad360cefefbc3bd35226c5d23eadce42c1..3a9bda2bf422b14085c60b39a2c3df86fe0994bb 100644 --- a/arch/arm/configs/tegra_defconfig +++ b/arch/arm/configs/tegra_defconfig @@ -6,7 +6,6 @@ CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_CGROUPS=y CONFIG_CGROUP_SCHED=y -CONFIG_RT_GROUP_SCHED=y CONFIG_CGROUP_FREEZER=y CONFIG_CGROUP_CPUACCT=y CONFIG_CGROUP_DEBUG=y