[openib-general] uverbs ibv_reg_mr return same lkey value

[ardavis]

Roland Dreier wrote:

>    ardavis> I noticed ibv_reg_mr always returns the same lkey of 0
>    ardavis> (per device) which presents a problem with udapl since
>    ardavis> the lkey is used as the context in the lmr hash table to
>    ardavis> avoid re-use. Is there a reason that you choose not to
>    ardavis> make this unique?
>
>I'm not sure I follow the question.  On my system ibv_reg_mr() returns
>a different, non-zero L_Key for each region that is registered.  The
>L_Key is guaranteed to be unique among all the memory regions
>currently registered with a given device.  I don't see how it's
>possible to get L_Key 0 for any memory region (since that L_Key is
>reserved by Mellanox HCA firmware), and I'm actually not sure what you
>mean by "0 (per device)."
>
>If you are seeing mr->lkey == 0 after a call to ibv_reg_mr(), then
>something is going wrong either in your code or in libibverbs or
>libmthca.  Can you post your code where you see that happen?
>
>If uDAPL is assuming that L_Keys are globally unique even with
>multiple HCAs, then uDAPL needs to be fixed, since a completely
>compliant verbs implementation may not satisfy that condition.
>
> - R.
>
>  
>
the only assumption is a unique lkey across the device. In my case, I am 
seeing a lkey of 0 returned for every memory region created on this 
device, however the rkey is changing. 

mr_register: lkey=0x0, rkey=0x5 ln=72 priv=1

pingpong looks ok...

  "ibv_reg_mr: mr 0x506ea0 mr->lkey a002c mr->rkey a002c"
  local address:  LID 0x0012, QPN 0x010406, PSN 0xdd3db0

so nevermind...my bad! .I will dig a little deeper.

    -arlin