[openib-general] APM support in openib stack

[Venkatesh Babu]

  I tried this patch and it is working fine. Now if I remove the both 
the cables connected to the destination, the IB_WC_RETRY_EXC_ERR on the 
first outstanding WR on a CQ as expected.

 With this patch I think all my APM related isses were resolved.

 Dotan, you can check this fix into the OFED svn. Thanks for providing 
the fix.

 VBabu

>
> I checked the code of the file cm.c (if OFED 1.1) and the attribute 
> alt_timeout is not mentioned anywhere in this code.
> I believe that the value of this attribute is set to zero, which means 
> that the QP will wait infinite time to the answer (that will never come).
>
> Venkatesh, can you check this issue by querying the QP attributes 
> after the path was migrated?
> I think that you will find that the value of the timeout attribute is 
> zero.
>
> Sean, i don't familiar with the cm.c code, but i believe that the 
> following patch will solve this issue:
>
> Index: last_stable/drivers/infiniband/core/cm.c
> ===================================================================
> --- last_stable.orig/drivers/infiniband/core/cm.c       2006-10-29 
> 16:58:08.000000000 +0200
> +++ last_stable/drivers/infiniband/core/cm.c    2006-10-29 
> 17:31:57.000000000 +0200
> @@ -3221,6 +3221,7 @@ static int cm_init_qp_rtr_attr(struct cm
>                if (cm_id_priv->alt_av.ah_attr.dlid) {
>                        *qp_attr_mask |= IB_QP_ALT_PATH;
>                        qp_attr->alt_port_num = 
> cm_id_priv->alt_av.port->port_num;
> +                       qp_attr->alt_timeout = 
> cm_id_priv->alt_av.packet_life_time;
>                        qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
>                }
>                ret = 0;
>
>
> thanks
> Dotan