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

[luca abeni]

Hi all,

On Fri, 23 Oct 2026 07:16:10 -1000
Tejun Heo <tj@xxxxxxxxxx> wrote:

> 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.

Yuri is working on an updated version of the patchset... If everything
goes well, a new RFC should arrive in few weeks :)


			Luca