[ewg] Changing min_rnr_timer and timeout attributes of QP

Hefty, Sean sean.hefty at intel.com
Wed Feb 6 22:42:04 PST 2013


> > I am trying to change min_rnr_timer and timeout attribute of QP from the
> Linux
> > kernel (RHEL6.3). The QP is created using rdma_create_qp() of rdma_cm
> moduleand
> > not ib_create_qp() as I want a generic code to work over IB as well as ROCEE.
> 
> These cannot be changed directly.  The min_rnr_timeout is set to 0, which is
> the maximum.  The timeout value is determined based on the packet lifetime
> reported by the SA.  You may be able to configure the SM to set a higher/lower
> packet lifetime.

Actually... from the kernel, I think calling ib_create_qp() works with IB and RoCE, but not iWarp.  You can still use the rdma_cm to connect, but transition the QPs yourself using rdma_init_qp_attr() and ib_modify_qp().

- Sean



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