From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=193.142.43.55 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792786072; b=2pn7LK1ObNpo4rmPJRb8q7DJHtBdQKvnu9gFLz54S6FTp4D2B9JN9mBb8abl12rnsp0h F7nXfuxVccGv0aI82/4dB3ChfMxcpk521ofjtSJ7zt8/DHH84rLFc1yTwC1sNAqxRt1hp s2lPkGjuccyxJOquGk4hjHTy0BSdMCqnBmiF3A/OyLVdFMl/VTq8A1Px14pspH3X5tRhr O93wDbS6LayNoKej89Px87Aje9Jlez3YqUcdt7uHvzTjcr0p/WuRgXMEbKwVr7lik4ppr /mp6hyZkmzXtvCdU9JCs9vXZPg6RSoJqAoZ0eRo96hoi15EE8DZVcam3LH7HjpIXICw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792786072; h=DMARC-Filter:Date:DKIM-Signature:DKIM-Signature:From:To:Cc:Subject: Message-ID:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To; bh=EuB51aRYMoB3ieHrj2HnljEvnH4sVtaaiFVu6E2r2rI=; b=qDXB3hEOSx+RmZzJZyPIKFPc5Gw8FGLanv9rPwkhzBUR37G/DHML+O2hGb73JV2TIq55 1WYV/6SrlxzYhpam4Ok8MbMr+9oDKGkMs8JqpwDGQHSnJMMIVhzu6520rKY/XsFFFpSCp 8lp9e71xOaZsHoFU+eyvNnLjOErYjVMVThc6PKI/Q70SGKw4nX9DAJ7W/bchXKQDQ6iDy atkZ8JofX31dMTiKCpJA3jrfMNeTpXrSqAFGPKHbmqWZMtfIK4ea/bkN4n5zazQ6LiM0b QsvS0aVRRfb7oX7zqBlca+Jegj4tx8iB1JxjgR9z6241XT3dHLU2MFfm+LV7sihjZsQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=HkSUsKbf; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b="/YMLS10H"; arc=none smtp.remote-ip=193.142.43.55 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56B8A606A31A; Fri, 23 Oct 2026 20:07:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 56B8A606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=HkSUsKbf; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=/YMLS10H Date: Fri, 23 Oct 2026 22:07:48 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1792786070; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=EuB51aRYMoB3ieHrj2HnljEvnH4sVtaaiFVu6E2r2rI=; b=HkSUsKbfuJQTn0aaj9vXHYfaR5vi75/PcqdXUYMySN2iIr91wW/mztEkKebDB94J+iA2fF LsA5wpYac5ZQRJm4Z1pMVNcUOabu1pjkSlgN4joSCQ2gv4ukBXb1t3kTibZKKvBnBzJHdW xMBRrUjYkBdL52PcIp3nFncCUPxd+5BFwbUXZLTDb3xbYw5KMpNBoAW6RQHt2TgH5sSnZ/ y7l8kT7Ct9Emgmeq58s5vJ+0OKVBbzTUqoa92hmVQSpHMvnuqWv+e2bk/qx3wFJFTajzpx IyKukRtXvCX23Le7W14HD3tpuiQLsWsuV2BOt5tXnA3+Q0bcL7fglkU4hXCMRw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1792786070; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=EuB51aRYMoB3ieHrj2HnljEvnH4sVtaaiFVu6E2r2rI=; b=/YMLS10HHiqlizs6HC1SdrWf4xHEd3TT3+P+2jr2SjCad/8NNgyMe33Ga74Py6hP5yeGhy 0ilMSvQDMfQPVcAQ== From: Sebastian Andrzej Siewior To: Tejun Heo Cc: linux-rt-devel@lists.linux.dev, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , K Prateek Nayak , Johannes Weiner , Michal =?utf-8?Q?Koutn=C3=BD?= , John Ogness , Shrikanth Hegde , Yuri Andriaccio , Yuri Andriaccio , Luca Abeni Subject: Re: [RFC] RT throttling, DL/ fair server, RT_GROUP_SCHED and everything Message-ID: <20261023200748.YZjSwZ48@linutronix.de> References: <20261023161348.t3lpPLQZ@linutronix.de> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On 2026-10-23 07:16:10 [-1000], Tejun Heo wrote: > Hello, Sebastian. Hi Tejun, > On Fri, Oct 23, 2026 at 06:13:48PM +0200, Sebastian Andrzej Siewior wrote: > > - Remove CONFIG_RT_GROUP_SCHED > > [ ] Yes [ ] No, because > > _____________________ > > RT_GROUP_SCHED in its current form isn't widely useful. No major distro > kernel enables it (Fedora, RHEL/CentOS Stream, Debian, Ubuntu, openSUSE, > Arch and the Android GKI defconfig, PREEMPT_RT flavors included). I have > no objection to removing it. Perfect. > There was an attempt to make it more useful: the Hierarchical Constant > Bandwidth Server (HCBS) patchset from Yuri Andriaccio and Luca Abeni. It > replaces RT_GROUP_SCHED with per-cgroup deadline servers and a cgroup2 > interface. The last posting was RFC v6 in June: > > https://lore.kernel.org/all/20260608121546.69910-1-yurand2000@gmail.com/ Yes, I am aware of this. It replaces RT_GROUP_SCHED and does not rely on it (as far as I remember). > The effort seems to have stalled. > > Thanks. Sebastian