Re: [PATCH v2] RDMA/cma: Make CM response timeout and # CM retries configurable

From: Bart Van Assche
Date: Thu Jun 13 2019 - 11:33:38 EST


On 6/13/19 7:25 AM, Doug Ledford wrote:
So, to revive this patch, what I'd like to see is some attempt to
actually quantify a reasonable timeout for the default backlog depth,
then the patch should actually change the default to that reasonable
timeout, and then put in the ability to adjust the timeout with some
sort of doc guidance on how to calculate a reasonable timeout based on
configured backlog depth.

How about following the approach of the SRP initiator driver? It derives the CM timeout from the subnet manager timeout. The assumption behind this is that in large networks the subnet manager timeout has to be set higher than its default to make communication work. See also srp_get_subnet_timeout().

Bart.