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

[Sebastian Andrzej Siewior]

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@xxxxxxxxx/

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