This avoids having to deal with the nr_hw_queues = 1 case in the various
queue mapping helpers by special casing it in the blk-mq core.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Shaohua Li <shli@xxxxxxxxxx>
---
block/blk-mq.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 041f7b7fa0d6..50d1f069d83b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2458,9 +2458,20 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
return 0;
}
+static int blk_mq_map_single_queue(struct blk_mq_tag_set *set)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ set->mq_map[cpu] = 0;
+ return 0;
+}
+
static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
{
- if (set->ops->map_queues)
+ if (set->nr_hw_queues == 1)
+ return blk_mq_map_single_queue(set);
+ else if (set->ops->map_queues)
return set->ops->map_queues(set);
else
return blk_mq_map_queues(set);
--
2.11.0
