Re: [RFC] RT throttling, DL/ fair server, RT_GROUP_SCHED and everything

[Tejun Heo]

Hello, Sebastian.

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.

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@xxxxxxxxx/

The effort seems to have stalled.

Thanks.

--
tejun