Re: [PATCH RFC v4 2/3] sched: Avoid placing RT threads on cores handling long softirqs

[Alexander Gordeev]

On Sat, Oct 22, 2022 at 06:34:37PM +0000, Joel Fernandes wrote:
> > In my reading of your approach if you find a way to additionally
> > indicate long softirqs being handled by the remote ksoftirqd, it
> > would cover all obvious/not-corner cases.
> 
> How will that help? The long softirq executing inside ksoftirqd will disable
> preemption and prevent any RT task from executing.

Right. So the check to deem a remote CPU unfit would (logically) look like this:

(active | pending | ksoftirqd) & LONG_SOFTIRQ_MASK

> Did I miss something?

Or me :)

> thanks,
> 
>  - Joel
>