Re: [PATCH net-next 1/2] sched/topology: Expose sched_numa_find_closest

From: Peter Zijlstra
Date: Mon Jul 18 2022 - 06:19:56 EST


On Sun, Jul 17, 2022 at 08:23:00AM +0300, Tariq Toukan wrote:
> This logic can help device drivers prefer some remote cpus
> over others, according to the NUMA distance metrics.
>
> Reviewed-by: Gal Pressman <gal@xxxxxxxxxx>
> Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
> ---
> include/linux/sched/topology.h | 2 ++
> kernel/sched/topology.c | 1 +
> 2 files changed, 3 insertions(+)
>
> diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
> index 56cffe42abbc..d467c30bdbb9 100644
> --- a/include/linux/sched/topology.h
> +++ b/include/linux/sched/topology.h
> @@ -61,6 +61,8 @@ static inline int cpu_numa_flags(void)
> {
> return SD_NUMA;
> }
> +
> +int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
> #endif
>
> extern int arch_asym_cpu_priority(int cpu);
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index 05b6c2ad90b9..688334ac4980 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -2066,6 +2066,7 @@ int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
>
> return found;
> }
> +EXPORT_SYMBOL(sched_numa_find_closest);

EXPORT_SYMBOL_GPL() if anything.

Also, this thing will be subject to sched_domains, that means that if
someone uses cpusets or other means to partition the machine, that
effects the result.

Is that what you want?