Re: [PATCH v5] sched_ext: Introduce NUMA awareness to the default idle selection policy

[Tejun Heo]

On Tue, Oct 29, 2024 at 11:16:18AM +0100, Andrea Righi wrote:
> Similarly to commit dfa4ed29b18c ("sched_ext: Introduce LLC awareness to
> the default idle selection policy"), extend the built-in idle CPU
> selection policy to also prioritize CPUs within the same NUMA node.
> 
> With this change applied, the built-in CPU idle selection policy follows
> this logic:
>  - always prioritize CPUs from fully idle SMT cores,
>  - select the same CPU if possible,
>  - select a CPU within the same LLC domain,
>  - select a CPU within the same NUMA node.
> 
> Both NUMA and LLC awareness features are enabled only when the system
> has multiple NUMA nodes or multiple LLC domains.
> 
> In the future, we may want to improve the NUMA node selection to account
> the node distance from prev_cpu. Currently, the logic only tries to keep
> tasks running on the same NUMA node. If all CPUs within a node are busy,
> the next NUMA node is chosen randomly.
> 
> Signed-off-by: Andrea Righi <arighi@xxxxxxxxxx>

Applied to sched_ext/for-6.13.

Thanks.

-- 
tejun