Re: [PATCH] tests/subnet_discover: discover test utility

Hal Rosenstock
2009-12-21T14:02:56Z

On Mon, Dec 21, 2009 at 2:35 AM, Sasha Khapyorsky <sashak-smomgflXvOZWk0Htik3J/w@public.gmane.org> wrote:
> Hi Ira,
>
> On 18:28 Sun 20 Dec     , Ira Weiny wrote:
>>
>> Yes, a similar mechanism would work in libibnetdisc.  However, it looks like you are doing a depth first search
>
> I wouldn't call it so, it is rather "parallel" than "first" depth or
> breath - discovery continues at first responding node doesn't matter how
> was it queried in depth or in breath.

Does anything limit the amount of parallelism ?

>
>> which I fear might exceed the path count limit in a DR path?
>
> Right, hops count should be limited. I will add this.
>
>> Is this how OpenSM works?
>
> I think so. The difference is that OpenSM has a limit of outstanding
> MADs on the wire and subnet_discover doesn't (and there could be a lot
> of MADs).

Isn't that dangerous in a real subnet ?

-- Hal

>
>> I was trying to do a breath first search like ibnetdiscover does.
>>
>> >
>> > Would you like to look at this?
>>
>> No problem, I have enclosed the output from a run on Hyperion.
>> There appears to be a lot of errors.  I am not sure what the issue is right off.  I have included an ibnetdiscover output for comparision.
>
> Thanks.
>
> An errors are response timeouts. I guess that most of them are due
> to switches' VL15 overflow (could be verified by VL15Dropped counter
> evaluation). Will look at this deeply.
>
> Sasha
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