[ofa-general] minimum sw components requirement for driver/opensm in a single unmanaged switch network

[Hal Rosenstock]

On Thu, Jul 10, 2008 at 7:47 PM, Yicheng Jia <YJia at tmriusa.com> wrote:
>
>> You would also need to walk the ports to active (via MADs) after setting
>> the LIDs as well as setup the switch forwarding table (LFT).
>
> Are these done by opensm?

Yes.

> Are these only two tasks that need to be done by
> opensm in a single unmanaged switch network?

No; I think another task was mentioned in Jim's minimalist approach
email and there are a few others. Just using OpenSM is much simpler
IMO unless you want to invest some work in learning what needs to be
done and how to do it.

-- Hal

> Best,
> Yicheng
>
>
>
> Hal Rosenstock <hrosenstock at xsigo.com>
>
> 07/10/2008 04:39 PM
>
> To
> Jim Mott <jim at mellanox.com>
> cc
> Yicheng Jia <YJia at tmriusa.com>, general at lists.openfabrics.org
> Subject
> RE: [ofa-general] minimum sw components requirement for        driver/opensm
> in a single unmanaged switch network
>
>
>
>
> On Thu, 2008-07-10 at 14:17 -0700, Jim Mott wrote:
>> If you want to avoid all the SM stuff, and are willing to program the
>> switches directly (a few mads),
>
> You would also need to walk the ports to active (via MADs) after setting
> the LIDs as well as setup the switch forwarding table (LFT).
>
> -- Hal
>
>> then I've used schemes like:
>>
>>
>>
>> Node LID=base + (switch port * constant) (base=0, constant = 1 works)
>>
>>
>>
>> Then to figure out QP connections, you just use a function of 3
>> parameters:
>>
>>   my_qp_num = fn_sqp(my_node, target_node, qp_num)
>>
>>   target_qp_num = fn_tqp(my_node, target_node, qp_num)
>>
>> Where qp_num is a small number between 0 and the maximum number of QPs
>> you need active between any 2 endpoints.
>>
>>
>>
>> With the above scheme, you know your node_id (switch port number),
>> your lid, the lid of the target node,  and the QPs on both sides.
>> From there on, it is clear sailing.  You don't even need to send MADs;
>> just transition the QP up and try and use it.  If it works, you are
>> done.  If not, reset, up, wait for him to connect and send something
>> to you.  A little timer to make sure everybody retries once in awhile
>> and what can go wrong?
>>
>>
>>
>> Jim
>>
>> From:general-bounces at lists.openfabrics.org [mailto:general-
>> bounces at lists.openfabrics.org] On Behalf Of Yicheng Jia
>> Sent: Thursday, July 10, 2008 2:59 PM
>> To: general at lists.openfabrics.org
>> Subject: [ofa-general] minimum sw components requirement for
>> driver/opensm in a single unmanaged switch network
>>
>>
>>
>>
>>
>> Hi Folks,
>>
>> I have a IB network which consists of only a single unmanaged switch,
>> all end nodes connecting with the switch only need to do RDMA
>> read/write operation with each other. My question is, what are the
>> indispensable modules in driver's core and opensm that make the
>> network up and run?
>>
>> I've been using only ib_mad module in driver's core with a managed
>> switch before, and the network works fine. So I assume that only the
>> ib_mad module in driver's core and SM in opensm are mandatory in my
>> network. The LIDs are assigned by them. The SA and CM modules are not
>> useful in my case. Am I right?
>>
>> I need to minimize driver and opensm to fit them in my network, the
>> HCA driver is mthca.
>>
>> Best,
>> Yicheng
>>
>> _____________________________________________________________________________
>> Scanned by IBM Email Security Management Services powered by
>> MessageLabs. For more information please visit http://www.ers.ibm.com
>>
>> _____________________________________________________________________________
>>
>>
>> _______________________________________________
>> general mailing list
>> general at lists.openfabrics.org
>> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general
>>
>> To unsubscribe, please visit
>> http://openib.org/mailman/listinfo/openib-general
>
>
> _____________________________________________________________________________
> Scanned by IBM Email Security Management Services powered by MessageLabs.
> For more information please visit http://www.ers.ibm.com
> _____________________________________________________________________________
>
>
> _____________________________________________________________________________
> Scanned by IBM Email Security Management Services powered by MessageLabs.
> For more information please visit http://www.ers.ibm.com
> _____________________________________________________________________________
>
> _______________________________________________
> general mailing list
> general at lists.openfabrics.org
> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general
>
> To unsubscribe, please visit
> http://openib.org/mailman/listinfo/openib-general
>