linux-kernel - Re: [RFC PATCH v4 18/28] sched/rt: Remove support for cgroups-v1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aXCzuSD7uXjfkxTU@jlelli-thinkpadt14gen4.remote.csb>
Date: Wed, 21 Jan 2026 12:08:41 +0100
From: Juri Lelli <juri.lelli@...hat.com>
To: Yuri Andriaccio <yurand2000@...il.com>
Cc: Ingo Molnar <mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Dietmar Eggemann <dietmar.eggemann@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
	Valentin Schneider <vschneid@...hat.com>,
	linux-kernel@...r.kernel.org,
	Luca Abeni <luca.abeni@...tannapisa.it>,
	Yuri Andriaccio <yuri.andriaccio@...tannapisa.it>
Subject: Re: [RFC PATCH v4 18/28] sched/rt: Remove support for cgroups-v1

Hello,

On 01/12/25 13:41, Yuri Andriaccio wrote:
> Disable control files for cgroups-v1, and allow only cgroups-v2. This
> should simplify maintaining the code, also because cgroups-v1 are
> deprecated.

I still wonder if we want/need to be a little more verbose about why we
think this is good, as it is quite a change. But, I'll let Peter and
others to chime in.

> Set the default rt-cgroups runtime to zero, otherwise a cgroup-v1 kernel
> will not be able to start SCHED_DEADLINE tasks. The bandwidth for
> rt-cgroups must then be manually assigned after the kernel boots.
> 
> Signed-off-by: Yuri Andriaccio <yurand2000@...il.com>
> ---

...

>  static int __init cpu_rt_group_init(void)
>  {
> -	if (!rt_group_sched_enabled())
> -		return 0;
> -
> -	WARN_ON(cgroup_add_legacy_cftypes(&cpu_cgrp_subsys, rt_group_files));
>  	return 0;
>  }
>  subsys_initcall(cpu_rt_group_init);

Looks like the whole function can be removed?

Thanks,
Juri