blk-mq: bump max tag depth to 10K tags
For some scsi-mq cases, the tag map can be huge. So increase the
max number of tags we support.
Additionally, don't fail with EINVAL if a user requests too many
tags. Warn that the tag depth has been adjusted down, and store
the new value inside the tag_set passed in.
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4e4cd62..a6ee74e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1967,13 +1967,19 @@
return NOTIFY_OK;
}
+/*
+ * Alloc a tag set to be associated with one or more request queues.
+ * May fail with EINVAL for various error conditions. May adjust the
+ * requested depth down, if if it too large. In that case, the set
+ * value will be stored in set->queue_depth.
+ */
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
{
int i;
if (!set->nr_hw_queues)
return -EINVAL;
- if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH)
+ if (!set->queue_depth)
return -EINVAL;
if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
return -EINVAL;
@@ -1981,6 +1987,11 @@
if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue)
return -EINVAL;
+ if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
+ pr_info("blk-mq: reduced tag depth to %u\n",
+ BLK_MQ_MAX_DEPTH);
+ set->queue_depth = BLK_MQ_MAX_DEPTH;
+ }
set->tags = kmalloc_node(set->nr_hw_queues *
sizeof(struct blk_mq_tags *),
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 0feedeb..a002cf1 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -135,7 +135,7 @@
BLK_MQ_S_STOPPED = 0,
BLK_MQ_S_TAG_ACTIVE = 1,
- BLK_MQ_MAX_DEPTH = 2048,
+ BLK_MQ_MAX_DEPTH = 10240,
BLK_MQ_CPU_WORK_BATCH = 8,
};