[openib-general] Re: Questions about mad_test

[Hal Rosenstock]

Hi Pradeep,

On Fri, 2005-10-07 at 15:19, Pradeep Satyanarayana wrote:
> I am hoping some one will be able to help me out with a few answers
> saving me some debug time, or having to expend effort on something
> that is already known.
> I was trying to execute mad_test and found that it errors out.

What is your command invocation ? Can you send the output of
ibnetdiscover ?

>  For some reason it does not like the DR Path that I gave it.
> 
> 1. I ran ibnetdiscover and got the set of LIDs that I use is DR Path.
> Is that correct way to go about it?
> It always errors out with something like: hop 0 != 0 or hop 1 !=
> dev_port

It's telling you the DR path you specified is invalid.

LIDs go "direct" and are hardware forwarded (via LID routing). DR is
uses a list of next hop (switch) ports (and not LIDs) and is firmware or
software forwarded usually although that is more an implementation than
architectural. See IBA 1.2 14.2.2 p.797 on for more on DR SMPs (MADs).

> 2. Also there is an expectation of there being a device
> /dev/infiniband/mthca0/ports/1/mad (using all defaults in this case)
> -is that correct? Any specific major and minor numbers I must use?

No. It just accesses those and some /sys/class/infiniband infiniband_mad
files.

> 3. Anything else that I am missing?
> 
> I am using this from trunk 3675 on 2.6.13 kernel.
> 
> Thanks in advance for all the help!
> 
> Pradeep
> pradeep at us.ibm.com