[PATCH 1/1] blk-mq: map all HWQ also in hyperthreaded system

[Max Gurtovoy]

On 6/28/2017 5:58 PM, Sagi Grimberg wrote:
>
>> +static int cpu_to_queue_index(unsigned int nr_queues, const int cpu,
>> +                  const struct cpumask *online_mask)
>>   {
>> -    return cpu * nr_queues / nr_cpus;
>> +    /*
>> +     * Non online CPU will be mapped to queue index 0.
>> +     */
>> +    if (!cpumask_test_cpu(cpu, online_mask))
>> +        return 0;
>
> Why not map offline cpus to what they would've map to if they were
> online?

I didn't change logic for offline cpu's.
Should it be done in this patch ?

>
>> +        if (cpu < nr_queues) {
>> +            map[cpu] = cpu_to_queue_index(nr_queues, cpu, online_mask);
>> +        } else {
>> +            first_sibling = get_first_sibling(cpu);
>> +            if (first_sibling == cpu)
>> +                map[cpu] = cpu_to_queue_index(nr_queues, cpu,
>> online_mask);
>
> This seems to be the only reference to online_mask left (on each side of
> the if statement. I think you can just not pass it and use
> cpu_online_mask in cpu_to_queue_index.

Another user of cpu_to_queue_index may want to send different mask.
Currently it's a static function so I guess we can do it.