[openib-general] APM support in openib stack

[somenath]

Sean Hefty wrote:

> somenath wrote:
>
>> any idea when this stuff will get done?
>
>
> As a rough estimate, Q1, though I will try to get to it after adding 
> support for SA events, which likely would be near late November, early 
> December.  The framework in the ib_cm is there; I just need a way to 
> signal that failover has occurred.
>
>> another question: If one brings back the old path (after the first 
>> failure) and use the old path record
>> to do lap/apr then reenabling migration using LAP/APR should work, 
>> right?
>
>
> Yes.
>
>> next question is: which component is suppossed to change QP state to 
>> REARM? spec just says:
>> "based on a command from a management entity, the QP state is set to 
>> REARM" .
>
>
> The ib_cm does not perform any QP state transitions.  That is left up 
> to the user, since the CM is unaware of other actions related to the 
> QP that the user may be performing.


but this function

cm_init_qp_rts_attr(struct cm_id_private *cm_id_priv,
                   struct ib_qp_attr *qp_attr,
                   int *qp_attr_mask)

does perform the state transition using
if (cm_id_priv->alt_av.ah_attr.dlid) {
            *qp_attr_mask |= IB_QP_PATH_MIG_STATE;
            qp_attr->path_mig_state = IB_MIG_REARM;
        }

which works for me the first time I load path (using send REQ) and 
change state to RTS.

so, I am bit confused here. do you mean that CM will do the state 
transition first time and
not the next time?

thanks, som.


>
> - Sean