Re: [PATCH v3 0/3] sched_ext: Improve exit-time diagnostics

[Cheng-Yang Chou]

Hi Tejun,

On Tue, Apr 28, 2026 at 10:57:27PM -1000, Tejun Heo wrote:
> A few things I noticed that might be worth a follow-up:
> 
> 1. scx_rcu_cpu_stall() takes no cpu, so the captured exit_cpu ends
>    up being the detector rather than the stalled one. We could
>    probably plumb it through from print_other_cpu_stall(), where
>    the stalled cpu is known.

Do you mean we should change the function signatures to pass the stalled
CPU through, e.g. panic_on_rcu_stall(int stalled_cpu) and
scx_rcu_cpu_stall(int stalled_cpu)?

> 
> 2. scx_hardlockup_irq_workfn() already has the hung cpu locally, so
>    passing it via __scx_exit() might be a bit more robust than
>    relying on irq_work routing.
> 
> 3. Minor: "on cpu N" (kernel) vs "on CPU N" (UEI) - the casing
>    could probably match.
> 

I have a draft patch and can send it out. If Changwoo or anyone else is
already working on this, pls let me know!

-- 
Cheers,
Cheng-Yang