On 09/13/13 15:51, Jack Wang wrote:
On 09/13/2013 03:33 PM, Bart Van Assche wrote:
On 09/13/13 14:25, Jack Wang wrote:
I tried your srp-ha branch in github,
echo string
SRP2="id_ext=${THCA2_GUID},ioc_guid=${THCA2_GUID},dgid=${TGID_P2},pkey=${PKEY},service_id=${THCA2_GUID},can_queue=512"
to add_target failed with
ib_srp: unknown parameter or missing value 'can_queue=512
[ 122.405385] ' in target creation request
Do I miss something?
Hello Jack,
Have you already tried the same command with "echo -n" instead of "echo"
? If I remember correctly the SRP initiator doesn't like a newline at
the end of the string written into the sysfs add_target attribute.
Hope this helps,
Bart.
Thanks Bart,
You're right, that is the problem, with -n option I can set can_queue
successfully.
But cat /sys/class/scsi_host/hostx/can_queue still show 63
Looks like it cause by the logic below:
/*
1870 * Reserve credits for task management so we don't
1871 * bounce requests back to the SCSI mid-layer.
1872 */
1873 target->scsi_host->can_queue
1874 = min(target->req_lim - SRP_TSK_MGMT_SQ_SIZE,
1875 target->scsi_host->can_queue);
1876 target->scsi_host->cmd_per_lun
1877 = min_t(int, target->scsi_host->can_queue,
1878 target->scsi_host->cmd_per_lun);
Could you give some hint on this, why we need to update can_queue and
cmd_per_lun here?
Hello Jack,
What is the value of target->req_lim on your setup ? The initiator
limits the queue size to the target request limit because any attempt to
queue more commands would cause the target to reply with "BUSY" anyway.
Bart.
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