Re: sg_map failures when tuning SRP via ib_srp module parameters for maximum SG entries

Bart Van Assche
2016-03-13T01:29:02Z

On 03/12/16 16:58, Laurence Oberman wrote:
> Within srpt on the array I have options ib_srpt srp_max_req_size=4148
> On the client I also only have options ib_srpt srp_max_req_size=4148
>
> I have not tuned srp_sq_size as I was only aware of
>
> parm: srp_max_req_size:Maximum size of SRP request messages in bytes. (int)
> parm: srpt_srq_size:Shared receive queue (SRQ) size. (int)
> parm: srpt_service_guid:Using this value for ioc_guid, id_ext, and cm_listen_id instead of using the node_guid of the first HCA.
>
> Please explain what that does.

Hello Laurence,

The srp_sq_size parameter controls the send queue size per RDMA channel.
The default value of this parameter is 4096. I think this is the
parameter that has to be increased to avoid hitting "IB send queue full"
errors.