From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) (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 6BD3A15A843 for ; Tue, 9 Jul 2024 12:45:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720529152; cv=none; b=cj2qM80qOnkNvhs9BffQBPgsliIP8RvuRiU4LYD9TmdF3g2DDEnSu8C3Tj7jy9GtL3Iub1Q0pc8snL9ZNjAQ23oNN7CITv+im3HgInmD5NuLNXjSc7EzrIQdTg/OU1b8D4eVW7i3YLV4GXBMaXzjf1/lvTi94Rt3KMopkMA6Clw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720529152; c=relaxed/simple; bh=O9QjD7xyf7LdxqfElfMDNMZgFewgPFqt+hOvv1SP8XI=; h=From:Message-ID:Date:MIME-Version:Subject:To:Cc:References: In-Reply-To:Content-Type; b=OtY/plGUApt6O/OeZFvTDUJHmHgx2Navn5u8nhPYzfYCoZaSOGfyPP/D4SQ3v8hYi//OZvdtMiU2PgYxVJQiSDEddfS7ltEWKVlLApEq+j3OyLMdpBptNDXThZComdjiFhBCa3l9j/ilOoKB1t53D66NH8O5f+yUzMR+Jjvs8FQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Lk9zInG7; arc=none smtp.client-ip=209.85.214.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Lk9zInG7" Received: by mail-pl1-f195.google.com with SMTP id d9443c01a7336-1fb3037b47dso32823695ad.2 for ; Tue, 09 Jul 2024 05:45:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720529151; x=1721133951; darn=lists.linux.dev; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from:from:to :cc:subject:date:message-id:reply-to; bh=PTkMABYzGdhSQd9C4loTDYzycJLf8ODZaPM06fmE3pI=; b=Lk9zInG7I64D6YmsG6FChB5RY9ThTDBVLM9KQFcKTOZr9wIBVk3qAR0iM9FBQabnWv WdBNnyyVHJgxqxN/CHWR6BmJMzHUY4I5rm2Om/6zuAMzNN/UHP7iBWKRPBybmiwMJZQv uDLY9iqKqTCz+TKApwX1NdlosHXZ3zjYMuMVaglnTHXVXP+2u9js61dHPHPI5EU4umBb Ag/IMT0A+ClGt3sbX4z3x8QLQCCxsL8x7ic/V1RwuFWSIQPBi72TnH9CLN5MYd4z/xRP p7wncHqzD9j9ACCS1AlLUVdQDYycBN7Uqf3gFvEo1Z9EroqpzfaY/aNLRCqgYcfvDUex 6MRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720529151; x=1721133951; h=content-transfer-encoding:in-reply-to:content-language:references :cc:to:subject:user-agent:mime-version:date:message-id:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=PTkMABYzGdhSQd9C4loTDYzycJLf8ODZaPM06fmE3pI=; b=T6ajl5C8tk9vv3+1JEkvS42d0BdD8DBFstewW3+G4CrT/fzIX9MYn8t9ll08vejHPT re0BhjsBYIPG3/PUXLUnPelpSOGs8UBBpsmsXuquwhooax3wDuFGcx/T78ia+dG2+mv+ 8hxYcOgHkJL2QSY5SaVkjvbrr5egRa/wwcJcq8DK8aFwMK+G3SLmRoHyfgPp5rB9+tE8 69j0Z8LvG5dV08PgbnHDnwYDI8Seux76Svo34I/QZf6dcR2rtkAMiPYR92YuVb3km8MS rexvWeTxvf0u0SeYgt9bOJhB9lTLfNdu35KJgL9kD/Ml3w7pFeiJwXU8eV4+4b7GoRyo hIwQ== X-Forwarded-Encrypted: i=1; AJvYcCVlwtpDKGNuWRBNyn7Fyhg06j7fn2FGRIQdPZCI/HJACjEpr+AlrdCeecn91U7XSTXXwwHVdfRO/qkUKJ1pNjn33sp/B+1LXW4G X-Gm-Message-State: AOJu0YyllCDTYqzVS0LC8IWGIgpc3N4cjUqFeOlZFR3bTu4Mz9b++nxI hm67EzyjfimS4ufKTmJxT4KeXPAYp3Ipnu52jnV8SqHEWyRHEJos X-Google-Smtp-Source: AGHT+IFOaJNRaCw0x5duAR8ySF29N2zLhsw5jMvf8ySrYnWHRx3vmy5Ah54KY0oG4A60mrkmNodEQw== X-Received: by 2002:a05:6a20:734b:b0:1be:caf6:66e5 with SMTP id adf61e73a8af0-1c29820d407mr2618980637.6.1720529150564; Tue, 09 Jul 2024 05:45:50 -0700 (PDT) Received: from [127.0.0.1] ([103.156.242.195]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fbb6acf9a3sm15241475ad.255.2024.07.09.05.45.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Jul 2024 05:45:49 -0700 (PDT) From: Celeste Liu X-Google-Original-From: Celeste Liu Message-ID: <44535d2d-c95d-4673-b845-032669cf7abf@gmail.com> Date: Tue, 9 Jul 2024 20:45:38 +0800 Precedence: bulk X-Mailing-List: loongarch@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 6/6] arm: defconfig: drop RT_GROUP_SCHED=y from bcm2855/tegra/omap2plus To: Stefan Wahren , Kevin Hilman , Vladimir Kondratiev , Florian Fainelli , Ray Jui , Scott Branden Cc: linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Lennart Poettering , Icenowy Zheng , =?UTF-8?Q?Th=C3=A9o_Lebrun?= , Gregory CLEMENT , Michael Ellerman , "Naveen N . Rao" , Sven Joachim , Huacai Chen , Heinrich Schuchardt , Anup Patel , Nicholas Piggin , Thomas Bogendoerfer , Jonathan Hunter , Christophe Leroy , Broadcom internal kernel review list , Rich Felker , Russell King , Tony Lindgren , Guo Ren , linux-tegra@vger.kernel.org, Thierry Reding , linux-riscv@lists.infradead.org, Arnd Bergmann , linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, Palmer Dabbelt , linux-sh@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, loongarch@lists.linux.dev, Mykola Lysenko , Yoshinori Sato , Paul Walmsley , John Paul Adrian Glaubitz , linux-rpi-kernel@lists.infradead.org, WANG Xuerui References: <20240530111947.549474-8-CoelacanthusHex@gmail.com> <20240530111947.549474-14-CoelacanthusHex@gmail.com> <7hv81f78cy.fsf@baylibre.com> <6b7cfe69-4f72-490f-8e86-5343bd244a2d@gmx.net> Content-Language: en-GB-large In-Reply-To: <6b7cfe69-4f72-490f-8e86-5343bd244a2d@gmx.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 2024-07-09 20:26, Stefan Wahren wrote: > Hi Celeste, > > there is a typo in the subject line > > s/bcm2855/bcm2835 Will be included in next version. > > Am 09.07.24 um 01:49 schrieb Kevin Hilman: >> Celeste Liu writes: >> >>> 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 >>> >>> Signed-off-by: Celeste Liu >>> --- >>>   arch/arm/configs/bcm2835_defconfig   | 1 - >>>   arch/arm/configs/omap2plus_defconfig | 1 - >>>   arch/arm/configs/tegra_defconfig     | 1 - >> For omap2plus_defconfig: >> >> Acked-by: Kevin Hilman >> >> > For bcm2835_defconfig: > > Tested-by: Stefan Wahren