With multiple maps, nr_cpu_ids is no longer the maximum number of hardware queues we support on a given devices. The initializer of the tag_set can have set ->nr_hw_queues larger than the available number of CPUs, since we can exceed that with multiple queue maps.
Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Jens Axboe <[email protected]> --- block/blk-mq.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 0fab36372ace..60a951c4934c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2663,6 +2663,19 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, mutex_unlock(&q->sysfs_lock); } +/* + * Maximum number of queues we support. For single sets, we'll never have + * more than the CPUs (software queues). For multiple sets, the tag_set + * user may have set ->nr_hw_queues larger. + */ +static unsigned int nr_hw_queues(struct blk_mq_tag_set *set) +{ + if (set->nr_maps == 1) + return nr_cpu_ids; + + return max(set->nr_hw_queues, nr_cpu_ids); +} + struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, struct request_queue *q) { @@ -2682,7 +2695,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, /* init q->mq_kobj and sw queues' kobjects */ blk_mq_sysfs_init(q); - q->queue_hw_ctx = kcalloc_node(nr_cpu_ids, sizeof(*(q->queue_hw_ctx)), + q->nr_queues = nr_hw_queues(set); + q->queue_hw_ctx = kcalloc_node(q->nr_queues, sizeof(*(q->queue_hw_ctx)), GFP_KERNEL, set->numa_node); if (!q->queue_hw_ctx) goto err_percpu; @@ -2694,7 +2708,6 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, INIT_WORK(&q->timeout_work, blk_mq_timeout_work); blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); - q->nr_queues = nr_cpu_ids; q->tag_set = set; q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; @@ -2884,12 +2897,13 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) set->queue_depth = min(64U, set->queue_depth); } /* - * There is no use for more h/w queues than cpus. + * There is no use for more h/w queues than cpus if we just have + * a single map */ - if (set->nr_hw_queues > nr_cpu_ids) + if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) set->nr_hw_queues = nr_cpu_ids; - set->tags = kcalloc_node(nr_cpu_ids, sizeof(struct blk_mq_tags *), + set->tags = kcalloc_node(nr_hw_queues(set), sizeof(struct blk_mq_tags *), GFP_KERNEL, set->numa_node); if (!set->tags) return -ENOMEM; @@ -2932,7 +2946,7 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) { int i, j; - for (i = 0; i < nr_cpu_ids; i++) + for (i = 0; i < nr_hw_queues(set); i++) blk_mq_free_map_and_requests(set, i); for (j = 0; j < set->nr_maps; j++) { @@ -3064,7 +3078,7 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, lockdep_assert_held(&set->tag_list_lock); - if (nr_hw_queues > nr_cpu_ids) + if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids) nr_hw_queues = nr_cpu_ids; if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) return; -- 2.17.1
