On 08/14/2018 01:56 PM, jianchao.wang wrote:
> Hi Ming
>
> On 08/11/2018 03:12 PM, Ming Lei wrote:
>> +static blk_status_t scsi_admin_queue_rq(struct blk_mq_hw_ctx *hctx,
>> + const struct blk_mq_queue_data *bd)
>> +{
>> + struct scsi_device *sdev = scsi_req(bd->rq)->sdev;
>> +
>> + WARN_ON_ONCE(hctx->queue == sdev->request_queue);
>> +
>> + if (!__scsi_mq_get_budget(hctx, sdev))
>> + return BLK_STS_RESOURCE;
>> +
>> + return __scsi_queue_rq(hctx, bd, sdev);
>> +}
>
> Why does it return BLK_STS_RESOURCE here ?
>
> Do you want to use the following code branch in blk_mq_dispatch_rq_list to get the admin queue rerun ?
>
> else if (needs_restart && (ret == BLK_STS_RESOURCE))
> blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
>
> In theory, BLK_STS_DEV_RESOURCE should be returned here. However, I guess it will not work. Because
> the rr fashion loop restart has gone, the completion of normal queue will not restart the admin queue.
> If yes, please add some comment here to describe it. :)
>
Looks like the patch 10 could avoid the admin queue hung.
Thanks
Jianchao
