Re: [PATCH v2 4/7] sched/fair: Introduce sched_smt_siblings_idle()

[Chen Yu]

On 2022-12-23 at 21:28:50 -0800, Ricardo Neri wrote:
> On Thu, Dec 22, 2022 at 04:56:22PM +0000, Valentin Schneider wrote:
> > On 22/11/22 12:35, Ricardo Neri wrote:
> > > Architectures that implement arch_asym_cpu_priority() may need to know the
> > > idle state of the SMT siblings of a CPU. The scheduler has this information
> > > and functionality. Expose it.
> > >
> > > Move the existing functionality outside of the NUMA code.
> > >
> > 
> > test_idle_cores() does something similar without an iteration, did you
> > consider using that instead?
> 
> IIUC, test_idle_cores() returns true if there is at least one idle core in
> the package. In my case, I need to know the idle state of only the SMT
> siblings of a specific CPU. Am I missing something?
>
I guess a similar one is select_idle_core(), but it also consider the CPU with
SCHED_IDLE task as idle. Is CPU with SCHED_IDLE task a candidate in your
scenario?

thanks,
Chenyu
> Thanks and BR,
> Ricardo