On Tue, Jul 04, 2017 at 10:55:08AM +0300, Sagi Grimberg wrote:
> unlike blk_mq_stop_hw_queues and blk_mq_start_stopped_hw_queues
> quiescing/unquiescing respects the submission path rcu grace.
>
> Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
> ---
> drivers/nvme/host/pci.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index eb729ff70e7d..df7c8a355075 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1125,7 +1125,7 @@ static int nvme_suspend_queue(struct nvme_queue *nvmeq)
> spin_unlock_irq(&nvmeq->q_lock);
>
> if (!nvmeq->qid && nvmeq->dev->ctrl.admin_q)
> - blk_mq_stop_hw_queues(nvmeq->dev->ctrl.admin_q);
> + blk_mq_quiesce_queue(nvmeq->dev->ctrl.admin_q);
>
> pci_free_irq(to_pci_dev(nvmeq->dev->dev), vector, nvmeq);
>
> @@ -1315,7 +1315,7 @@ static void nvme_dev_remove_admin(struct nvme_dev *dev)
> * user requests may be waiting on a stopped queue. Start the
> * queue to flush these to completion.
> */
> - blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
> + blk_mq_unquiesce_queue(dev->ctrl.admin_q);
> blk_cleanup_queue(dev->ctrl.admin_q);
> blk_mq_free_tag_set(&dev->admin_tagset);
> }
> @@ -1351,8 +1351,10 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
> dev->ctrl.admin_q = NULL;
> return -ENODEV;
> }
> - } else
> - blk_mq_start_stopped_hw_queues(dev->ctrl.admin_q, true);
> + } else {
> + blk_mq_unquiesce_queue(dev->ctrl.admin_q);
> + blk_mq_kick_requeue_list(dev->ctrl.admin_q);
Again, blk_mq_kick_requeue_list() may not be required.
--
Ming
