[mvapich-discuss] configuring interfaces

[Hari Subramoni]

Hello David,

It is a warning, not an error which can cause execution to stop. However,
there are two caveats

1. As I mentioned in my previous e-mail this will not give you the best
performance at the network level. For instance, you may get much lower
bandwidth / much higher latency if you use the CH3 interface over QLogic
HCAs.

2. Please note that this is a combination that we do not test as it not
recommended by the vendor (QLogic). Hence, you *may* encounter errors while
running applications.

Regards,
Hari.


On Tue, Aug 19, 2014 at 1:08 PM, David Winslow <
david.winslow at serendipitynow.com> wrote:

> Thank you for the quick response. I have a follow up question. Can we run
> MVAPICH2 despite the message to use PSM (is it just a warning) or is it an
> error and the execution actually stops?
>
> The reason we are looking at using OFA-IB-CH3 is that the majority of
> options or configuration parameters offered by MVAPICH2 are not offered for
> the PSM interface such as MV2_USE_HUGEPAGES as well as many others. Is it
> accurate to assume that if the user guide (section 11) doesn't explicitly
> read that it supports PSM, then using the option has no impact on MVAPICH2
> at runtime?
>
> Thank you again.
> David
>
>
>
>
> On Tue, Aug 19, 2014 at 5:46 AM, Hari Subramoni <subramoni.1 at osu.edu>
> wrote:
>
>> Hello David,
>>
>> Yes, MVAPICH2 configured with the CH3 interface can run over QLogic
>> cards. However this may not lead to the best performance. The vendors of
>> QLogic HCAs say that for best performance, one needs to use the
>> PSM interface instead of the regular IB verbs interface with QLogic HCAs.
>> That is why MVAPICH2 gives the error message.
>>
>> You can configure MVAPICH2 for the nemesis interface and then load any
>> network module (netmod) you need. Please note that nemesis does not have
>> support for PSM interface currently. Please refer to the following section
>> of our userguide for more information on how to configure MVAPICH2 for the
>> nemesis interface.
>>
>>
>> http://mvapich.cse.ohio-state.edu/static/media/mvapich/mvapich2-2.0-userguide.html#x1-170004.9
>>
>> Regards,
>> Hari.
>>
>>
>> On Tue, Aug 19, 2014 at 12:32 AM, David Winslow <
>> david.winslow at serendipitynow.com> wrote:
>>
>>> Team,
>>> We are using Qlogic cards and MVAPICH 2.0 rc2.
>>>
>>> I have a couple of questions:
>>>
>>> 1. Can MVAPICH2 be configured to use CH3 interface even with QLogic
>>> cards without getting an error at runtime? We've done this and get a
>>> runtime error effectively saying we need to use PSM interface instead.
>>>
>>> 2. Can MVAPICH2 be configured with all of the interfaces and have the
>>> preferred interface chosen at runtime with a switch or parameter?
>>>
>>>
>>> Thank you
>>> David
>>>
>>>
>>> _______________________________________________
>>> mvapich-discuss mailing list
>>> mvapich-discuss at cse.ohio-state.edu
>>> http://mailman.cse.ohio-state.edu/mailman/listinfo/mvapich-discuss
>>>
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cse.ohio-state.edu/pipermail/mvapich-discuss/attachments/20140820/b8c60abd/attachment.html>