Reserved requests are internal to the driver and we wouldn't know
if and how they should be merged.
So disable the elevator for reserved tags.
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
block/blk-mq.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 08a6248d8536..f6711a61ba3b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -368,17 +368,18 @@ static struct request *blk_mq_get_request(struct request_queue *q,
if (data->cmd_flags & REQ_NOWAIT)
data->flags |= BLK_MQ_REQ_NOWAIT;
+ if (data->flags & BLK_MQ_REQ_RESERVED)
+ e = NULL;
+
if (e) {
data->flags |= BLK_MQ_REQ_INTERNAL;
/*
* Flush requests are special and go directly to the
- * dispatch list. Don't include reserved tags in the
- * limiting, as it isn't useful.
+ * dispatch list.
*/
if (!op_is_flush(data->cmd_flags) &&
- e->type->ops.limit_depth &&
- !(data->flags & BLK_MQ_REQ_RESERVED))
+ e->type->ops.limit_depth)
e->type->ops.limit_depth(data->cmd_flags, data);
} else {
blk_mq_tag_busy(data->hctx);
--
2.16.4
