Add requests to the tail of the list instead of the front so that they are queued up in submission order. Remove the re-reordering in blk_mq_dispatch_plug_list, virtio_queue_rqs and nvme_queue_rqs now that the list is ordered as expected. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- block/blk-mq.c | 4 ++-- drivers/block/virtio_blk.c | 2 +- drivers/nvme/host/pci.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index ff0b819e35fc..270cfd9fc6b0 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1392,7 +1392,7 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) */ if (!plug->has_elevator && (rq->rq_flags & RQF_SCHED_TAGS)) plug->has_elevator = true; - rq_list_add_head(&plug->mq_list, rq); + rq_list_add_tail(&plug->mq_list, rq); plug->rq_count++; } @@ -2844,7 +2844,7 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) rq_list_add_tail(&requeue_list, rq); continue; } - list_add(&rq->queuelist, &list); + list_add_tail(&rq->queuelist, &list); depth++; } while (!rq_list_empty(&plug->mq_list)); diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index a19f24c19140..c0cdba71f436 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -514,7 +514,7 @@ static void virtio_queue_rqs(struct rq_list *rqlist) vq = this_vq; if (virtblk_prep_rq_batch(req)) - rq_list_add_head(&submit_list, req); /* reverse order */ + rq_list_add_tail(&submit_list, req); else rq_list_add_tail(&requeue_list, req); } diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index c3a00a13946d..39ba1d0c287d 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -943,7 +943,7 @@ static void nvme_queue_rqs(struct rq_list *rqlist) nvmeq = req->mq_hctx->driver_data; if (nvme_prep_rq_batch(nvmeq, req)) - rq_list_add_head(&submit_list, req); /* reverse order */ + rq_list_add_tail(&submit_list, req); else rq_list_add_tail(&requeue_list, req); } -- 2.45.2
