Re: [PATCH 1/2] sched/topology: Don't enable EAS on SMT systems

[Quentin Perret]

On Wednesday 26 Feb 2020 at 16:41:17 (+0000), Valentin Schneider wrote:
> EAS already requires asymmetric CPU capacities to be enabled, and mixing
> this with SMT is an aberration, but better be safe than sorry.
> 
> Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx>

Acked-by: Quentin Perret <qperret@xxxxxxxxxx>

Thanks,
Quentin

> ---
>  kernel/sched/topology.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index 00911884b7e7..76cd0a370b9a 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -360,6 +360,10 @@ static bool build_perf_domains(const struct cpumask *cpu_map)
>  		goto free;
>  	}
>  
> +	/* EAS definitely does *not* handle SMT */
> +	if (sched_smt_active())
> +		goto free;
> +
>  	for_each_cpu(i, cpu_map) {
>  		/* Skip already covered CPUs. */
>  		if (find_pd(pd, i))
> -- 
> 2.24.0
>