Re: [PATCH] sched/fair: Prevent cfs_rq from being unthrottled with zero runtime_remaining

[Hao Jia]

On 2025/10/15 10:51, Aaron Lu wrote:
> On Wed, Oct 15, 2025 at 09:43:20AM +0800, Hao Jia wrote:
> ... ...
> > Yes, I've already hit the cfs_rq->runtime_remaining < 0 condition in
> > tg_unthrottle_up().
> >
> > This morning, after applying your patch, I still get the same issue.
> > However, As before, because cfs_rq->curr isn't NULL,
> > check_enqueue_throttle() returns prematurely, preventing the triggering of
> > throttle_cfs_rq().
> >
> >
> > Some information to share with you.
>
> Can you also share your cgroup setup and related quota setting etc. and
> how to trigger it? Thanks.

I ran some internal workloads on my test machine with different quota 
settings, and added 10 sched messaging branchmark cgroups, setting their 
cpu.max to 1000 100000.

perf bench sched messaging -g 10 -t -l 50000 &

I'm not sure if the issue can be reproduced without these internal 
workloads.

Thanks,
Hao