Re: [External] Re: [PATCH v2] sched: RT bandwidth interface for cgroup unified hierarchy

[Michal Koutný]

On Thu, Jun 23, 2022 at 10:23:26AM +0800, Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> wrote:
> I don't know why v2 differ from v1 in the RT bandwidth control.. Is there
> some links of explanation? (CFS bandwidth control can work on v2 now.)

You can see some ideas in [1] (the v1 API allows configurations that are
not implemented).
And I'd also say more generally, that applying throttling to an RT task
is already a lost game (either it's a runaway meaning there's a bug
elsewhere or the RT task won't have sufficient runtime which defeats its
RTness).

> If the problem can't be solved, we have to unset CONFIG_RT_GROUP_SCHED.

AFAICT, this was enough so far (but RT group scheduling can still be
(re)worked).

HTH,
Michal

[1] https://www.kernel.org/doc/html/latest/scheduler/sched-rt-group.html