Re: [PATCH V5 0/9] nvme: pci: fix & improve timeout handling

jianchao.wang
2018-05-15T09:56:14Z

Hi ming

On 05/15/2018 08:33 AM, Ming Lei wrote:
> We still have to quiesce admin queue before canceling request, so looks
> the following patch is better, so please ignore the above patch and try
> the following one and see if your hang can be addressed:
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index f509d37b2fb8..c2adc76472a8 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1741,8 +1741,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
> dev->ctrl.admin_q = NULL;
> return -ENODEV;
> }
> - } else
> - blk_mq_unquiesce_queue(dev->ctrl.admin_q);
> + }
>
> return 0;
> }
> @@ -2520,6 +2519,12 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown, bool
> */
> if (shutdown)
> nvme_start_queues(&dev->ctrl);
> +
> + /*
> + * Avoid to suck reset because timeout may happen during reset and
> + * reset may hang forever if admin queue is kept as quiesced
> + */
> + blk_mq_unquiesce_queue(dev->ctrl.admin_q);
> mutex_unlock(&dev->shutdown_lock);
> }

w/ patch above and patch below, both the warning and io hung issue didn't reproduce till now.

@@ -1450,6 +1648,7 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
{
struct nvme_dev *dev = nvmeq->dev;
int result;
+ int cq_vector;

if (dev->cmb && use_cmb_sqes && (dev->cmbsz & NVME_CMBSZ_SQS)) {
unsigned offset = (qid - 1) * roundup(SQ_SIZE(nvmeq->q_depth),
@@ -1462,15 +1661,16 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
* A queue's vector matches the queue identifier unless the controller
* has only one vector available.
*/
- nvmeq->cq_vector = dev->num_vecs == 1 ? 0 : qid;
- result = adapter_alloc_cq(dev, qid, nvmeq);
+ cq_vector = dev->num_vecs == 1 ? 0 : qid;
+ result = adapter_alloc_cq(dev, qid, nvmeq, cq_vector);
if (result < 0)
- goto release_vector;
+ goto out;

result = adapter_alloc_sq(dev, qid, nvmeq);
if (result < 0)
goto release_cq;
-
+
+ nvmeq->cq_vector = cq_vector;
nvme_init_queue(nvmeq, qid);
result = queue_request_irq(nvmeq);
if (result < 0)
@@ -1479,12 +1679,12 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
return result;

release_sq:
+ nvmeq->cq_vector = -1;
dev->online_queues--;
adapter_delete_sq(dev, qid);
release_cq:
adapter_delete_cq(dev, qid);
- release_vector:
- nvmeq->cq_vector = -1;
+ out:
return result;
}

Thanks
Jianchao