Re: [PATCH v2 01/17] ibmvfc: add vhost fields and defaults for MQ enablement
From: Tyrel Datwyler <tyreld@linux.ibm.com>
Date: 2020-12-02 17:28:18
Also in:
linux-scsi, lkml
On 12/2/20 7:14 AM, Brian King wrote:
On 12/1/20 6:53 PM, Tyrel Datwyler wrote:quoted
Introduce several new vhost fields for managing MQ state of the adapter as well as initial defaults for MQ enablement. Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> --- drivers/scsi/ibmvscsi/ibmvfc.c | 9 ++++++++- drivers/scsi/ibmvscsi/ibmvfc.h | 13 +++++++++++-- 2 files changed, 19 insertions(+), 3 deletions(-)diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index 42e4d35e0d35..f1d677a7423d 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c@@ -5161,12 +5161,13 @@ static int ibmvfc_probe(struct vio_dev *vdev, const struct vio_device_id *id) } shost->transportt = ibmvfc_transport_template; - shost->can_queue = max_requests; + shost->can_queue = (max_requests / IBMVFC_SCSI_HW_QUEUES);This doesn't look right. can_queue is the SCSI host queue depth, not the MQ queue depth.
Our max_requests is the total number commands allowed across all queues. From
what I understand is can_queue is the total number of commands in flight allowed
for each hw queue.
/*
* In scsi-mq mode, the number of hardware queues supported by the LLD.
*
* Note: it is assumed that each hardware queue has a queue depth of
* can_queue. In other words, the total queue depth per host
* is nr_hw_queues * can_queue. However, for when host_tagset is set,
* the total queue depth is can_queue.
*/
We currently don't use the host wide shared tagset.
-Tyrel
quoted
shost->max_lun = max_lun; shost->max_id = max_targets; shost->max_sectors = IBMVFC_MAX_SECTORS; shost->max_cmd_len = IBMVFC_MAX_CDB_LEN; shost->unique_id = shost->host_no; + shost->nr_hw_queues = IBMVFC_SCSI_HW_QUEUES; vhost = shost_priv(shost); INIT_LIST_HEAD(&vhost->sent);