From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (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 72F33155A25; Tue, 9 Jul 2024 12:27:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.22 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720528071; cv=none; b=nD9bvEJAotJsFppV+EXyLLZVtM/ezDG22Vj9RbwAd2LU8pLwj07zDnenaIH9mVTqZ5xswRBCq/cMCIymQRcOS6bOtgyJjuZm/dgzSLA3Ofq2KGk/jp1vzIfnsuY4SbpQPaGBCMxcf2N+W9fS1tfuK5NjNyGNcfMZxYbU6MzPY6A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720528071; c=relaxed/simple; bh=rddHFdPI15PpKIujuf5oEVmDeSmCYfLpJ11QyQ+fRY4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KjAKTB6HYRpKXoSsHgagJhAHjELkiG8BB2y0T9oZrWa/gH0SI5+fvRW4le8JL3BIawyl3te82GdzHxrhWvkvaLKXcsb6KO1GL1KYvUcUMQVedJDSIHgd9KHIJiGVr6lVGF4rAKFJYDyrzTBZKWAK36wApdKgFlGN17qvjeAagzA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net; spf=pass smtp.mailfrom=gmx.net; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b=iNEPb9BL; arc=none smtp.client-ip=212.227.17.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.net header.i=wahrenst@gmx.net header.b="iNEPb9BL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.net; s=s31663417; t=1720527976; x=1721132776; i=wahrenst@gmx.net; bh=cCtoGEQ65O0NQHMFrW3/EWkn5s4oTQM/d6IPIcz9pxI=; h=X-UI-Sender-Class:Message-ID:Date:MIME-Version:Subject:To:Cc: References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding:cc:content-transfer-encoding: content-type:date:from:message-id:mime-version:reply-to:subject: to; b=iNEPb9BLGGngXSVlaV2Y5yqu2HXBUZ6ee4wlyeD4jUnl2jxZ3ROfuIaToeyDEeaM ChamxzSRAioqbTQp8qQsUWRZx6LYO2U4TDkJ2WguyL4GeMnS/G2WPcVCWu60zPjyP Vh4/Emn2CN8ZA9ZeReLL81xDo9eDREYSO5sUWQ54kuTiOBFZDGu7jfGWwBGdQDeDh P0LxqK8Qz8LN6ipLHH2iWKLgibppHN4KyaWtS/AgeoRMD1HZazIRu9s+vhbCnSVFp ziqSVnQ3zw9fnW13Q/cp2MCcrQip9PwUViOvp5M446wjyEbd+U4sBFRiCJlvYbaYo HGiM5AnAtFWbi3GPFw== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.1.127] ([37.4.248.43]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MVN6t-1sqlVn12E3-00Oj39; Tue, 09 Jul 2024 14:26:16 +0200 Message-ID: <6b7cfe69-4f72-490f-8e86-5343bd244a2d@gmx.net> Date: Tue, 9 Jul 2024 14:26:08 +0200 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org 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: Kevin Hilman , Celeste Liu , 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> Content-Language: en-US From: Stefan Wahren In-Reply-To: <7hv81f78cy.fsf@baylibre.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:Ej+PAwp/ZJkhkceEoIwv6AInmRQiACjrvJFoir5Nuj9E1MJRvQA hCU1+y5KPH/WQUoUAj38tdnqg1TsI3WE3557l+L+5Zlw+pyx5u7oihbFKJ0II0kgo4eAkC9 Qtrhsw6GW7j6n1LaLGg2lE46GZtD/AMneN85Q7N1yqHtfnzmF3zlp8522hgdV6zM7JOCk4j tUDmMBQyL0KKRh3tZUkgw== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:CY3hoQ/VQPY=;5QGFpAHuDX4v0nW4bbrXMcvM2hK vYnqvDsWKbcvHPlHjyAu1B7NjXCCKdEydnIkCb02e/O9SFu11zoROqN2443E6DETn+pRJ/ATw uC75juahlmOdRef/GIWmgUOF89ZxlNpamUGSRJMbcc/7acV3tyktqOTmeJxlUGm/SM9VqT22Y KZP+hHsXJbOD66Y88uvexJJ/bXGM6qzGenJ/FFefNIFQvSg81Mdj0TsYkE44jjuXFP6HOzvR7 sfK3tUSSa+VOVUCpuVLM/CT9tqP1ebBVbGW8i2F2iJ7ZCF+Abffzz7W0YklTXbVDGZYVtqr6B wU4xb4LGpbV+YuwE/Z6CVBsgXktSUuccyUQNSue62AT4J9eibvy9Fg2PZvseBR0pFd8th3MdM uAJzeRXqbTBGFlDwJkm836FDmGIeSgXZqToBqD7eb9BKLbEvtEApMusg+8DNNanWvdGfsZqB/ c/331otTYafTSC5+1UB2wPRsM9VvslvEU1EfZiIJBv2wiWFvAvSrsHoi5ueZYYmqPhfLTCaxF IDCbOQZKrbP/vbwSNwJZjo5ew3oOyDqL/o6yn4+Zp6zOM7nXI1D3bvIrxJCrK5gBDnttyqe/E bmiYbnssNvUEE7+bNEQ/MPt7xIsDe1kHCOeyFM5/vQeRHncgpuJ10i2uKdpGevOSohr3ghao6 9oj5jIeHgymEcQEZGDQeesjnPjhwreNbaW2YOd8FW1J8+MQKDdmNUo+Lo/iNHgTBrMtuB3Qil xzpqw3ifkOFSoOTrRRPfJ7EZGae7oJ7+jq0FHgCMSeUnAXDBRyAAVyYmc+ks93Us7II8klNBI aa5PFxwJb0lP/7+bdAbJrFmCfqj7iq087cOKXyG81KDIw= Hi Celeste, there is a typo in the subject line s/bcm2855/bcm2835 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