Re: [PATCH 5/8] virtio_blk: implement mq_ops->commit_rqs() hook
From: Ming Lei <hidden>
Date: 2018-11-28 02:10:42
Also in:
linux-nvme
On Mon, Nov 26, 2018 at 09:35:53AM -0700, Jens Axboe wrote:
quoted hunk ↗ jump to hunk
We need this for blk-mq to kick things into gear, if we told it that we had more IO coming, but then failed to deliver on that promise. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- drivers/block/virtio_blk.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6e869d05f91e..b49c57e77780 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c@@ -214,6 +214,20 @@ static void virtblk_done(struct virtqueue *vq) spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); } +static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) +{ + struct virtio_blk *vblk = hctx->queue->queuedata; + int qid = hctx->queue_num; + bool kick; + + spin_lock_irq(&vblk->vqs[qid].lock); + kick = virtqueue_kick_prepare(vblk->vqs[qid].vq); + spin_unlock_irq(&vblk->vqs[qid].lock); + + if (kick) + virtqueue_notify(vblk->vqs[qid].vq); +} + static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) {@@ -638,6 +652,7 @@ static void virtblk_initialize_rq(struct request *req) static const struct blk_mq_ops virtio_mq_ops = { .queue_rq = virtio_queue_rq, + .commit_rqs = virtio_commit_rqs, .complete = virtblk_request_done, .init_request = virtblk_init_request, #ifdef CONFIG_VIRTIO_BLK_SCSI-- 2.17.1
If .commit_rqs() is implemented, virtqueue_notify() in virtio_queue_rq() should have been removed for saving the world switch per .queue_rq() thanks, Ming