> Il giorno 21 nov 2022, alle ore 02:01, Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> ha scritto:
>
...
>
>> }
>>
>> static bool bfq_bio_merge(struct request_queue *q, struct bio *bio,
>> @@ -7144,6 +7159,8 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
>> {
>> struct bfq_data *bfqd;
>> struct elevator_queue *eq;
>> + unsigned int i;
>> + struct blk_independent_access_ranges *ia_ranges = q->disk->ia_ranges;
>>
>> eq = elevator_alloc(q, e);
>> if (!eq)
>> @@ -7187,10 +7204,31 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
>> bfqd->queue = q;
>>
>> /*
>> - * Multi-actuator support not complete yet, default to single
>> - * actuator for the moment.
>> + * If the disk supports multiple actuators, we copy the independent
>> + * access ranges from the request queue structure.
>> */
>> - bfqd->num_actuators = 1;
>> + spin_lock_irq(&q->queue_lock);
>> + if (ia_ranges) {
>> + /*
>> + * Check if the disk ia_ranges size exceeds the current bfq
>> + * actuator limit.
>> + */
>> + if (ia_ranges->nr_ia_ranges > BFQ_MAX_ACTUATORS) {
>> + pr_crit("nr_ia_ranges higher than act limit: iars=%d, max=%d.\n",
>> + ia_ranges->nr_ia_ranges, BFQ_MAX_ACTUATORS);
>> + pr_crit("Falling back to single actuator mode.\n");
>> + bfqd->num_actuators = 0;
>> + } else {
>> + bfqd->num_actuators = ia_ranges->nr_ia_ranges;
>> +
>> + for (i = 0; i < bfqd->num_actuators; i++)
>> + bfqd->ia_ranges[i] = ia_ranges->ia_range[i];
>> + }
>> + } else {
>> + bfqd->num_actuators = 0;
>
> That is very weird. The default should be 1 actuator.
> ia_ranges->nr_ia_ranges is 0 when the disk does not provide any range
> information, meaning it is a regular disk with a single actuator.
Actually, IIUC this assignment to 0 seems to be done exactly when you
say that it should be done, i.e., when the disk does not provide any
range information (ia_ranges is NULL). Am I missing something else?
Once again, all other suggestions applied. I'm about to submit a V7.
Thanks,
Paolo
