[ofw] What is the current support level for QoS in WinOF?

[Hal Rosenstock]

On Tue, Mar 24, 2009 at 3:34 AM, Diego Guella
<diego.guella at sircomtech.com> wrote:
> Hi Sean,
>
> ----- Original Message -----
>>
>> From: "Sean Hefty"
>> >Is QoS supported in WinOF?
>>
>> Definitely not to the extent supported by the Linux stack.
>>
>>> Is QoS supported in Mellanox WinOF?
>>> Alternatively, can I add a single Linux host to my fabric, just to run
>>> OFED
>>> (and opensm) on it to get full QoS support? Are there some
>>> incompatibilities
>>> between win-linux (about QoS)?
>>
>> I'm highly skeptical that the WinOF opensm supports QoS, but I don't know
>> for
>> certain.  Even using the OFED opensm, additional changes would still be
>> needed
>> to the WinOF host stack; for example, using new PathRecord fields.  There
>> shouldn't be any incompatibilities, but the WinOF stack won't provide the
>> SM
>> with enough information to support more advanced QoS partitioning.
>>
>> You may be able to use the OFED opensm to achieve some level of QoS,
>> depending
>> on how you want things separated.  If you can separate QoS based on HCA
>> ports,
>> you might have more success than trying to separate different applications
>> running on the same HCA port.
>
> I do have urgent time-sensitive traffic, and non-urgent traffic.
> The urgent traffic and the non-urgent traffic is generated from different
> hosts.
> I would like to differentiate them by using different SL, then configure QoS
> to give maximum priority to the urgent time-sensitive traffic, and minimum
> priority to the non-urgent traffic.

If you are expecting the SL to come from OpenSM, it would be best to
use the Linux OpenSM and likely the QoS Annex support but I don't know
enough about what you have in mind in terms of the end node Windows
ULPs and whether they use RDMA CM and/or CM or bypass them.

-- Hal

> Are you saying I can't do this in WinOF?
> And I can't do that even adding a Linux host that runs opensm (OFED
> version)?
>
> Traffic separation based on HCA port could be an option, but I need to think
> more about that.
> What can you do with that kind of QoS?
> Do you mark this HCA port as high-priority, that HCA port as low-priority,
> etc?
> What happens when a high-pri port sends traffic to a low-pri port? And
> vice-versa?
> What happens when a high-pri port sends traffic to a "normal" port (a port
> that is not marked as high-priority nor low-priority)?
> I'm using only RDMA Write with Imm in my system, although I'm interested in
> what happens on all types of traffic.
> If you know of a document that explains that, please let me know, I haven't
> found it by now.
>
>
> Thanks,
> Diego
>
> _______________________________________________
> ofw mailing list
> ofw at lists.openfabrics.org
> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ofw
>