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

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 7/18/2022 1:19 PM, Peter Zijlstra wrote:
> 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@nvidia.com>
>> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
>> ---
>>   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.

I'll fix.

> 
> 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?

Yes, it's good enough, at least as a first phase and basic functionality.
Later we might introduce whatever enhancements we find necessary.


Thanks,
Tariq