On Tue, Aug 23, 2022 at 11:50:05PM +0900, Suwan Kim wrote:
quoted hunk ↗ jump to hunk
@@ -409,6 +409,8 @@ static bool virtblk_add_req_batch(struct virtio_blk_vq *vq,
virtblk_unmap_data(req, vbr);
virtblk_cleanup_cmd(req);
rq_list_add(requeue_list, req);
+ } else {
+ blk_mq_start_request(req);
}
The device may see new requests as soon as virtblk_add_req() is called
above. Therefore the device may complete the request before
blk_mq_start_request() is called.
rq->io_start_time_ns = ktime_get_ns() will be after the request was
actually submitted.
I think blk_mq_start_request() needs to be called before
virtblk_add_req().
Stefan