[openib-general] Re: Re: Re: [PATCH] change Mellanox SDP workaround toa moduleparameter

[Michael S. Tsirkin]

Quoting r. Sean Hefty <mshefty at ichips.intel.com>:
> >>I didn't follow what changes are necessary to improve the connection 
> >>rate.  Can you clarify?
> >
> >
> >Changes in the CM protocol so that a 3 way handshake can occur so that
> >for example a lower MTU connection can be accepted with one REQ/REP/RTU
> >sequence without REQ/REJ then REQ/REP/RTU.
> 
> Okay - this is what I thought.  Personally, I don't think that it makes 
> sense to change the architecture to optimize for hardware that happens to 
> perform poorly under a given condition.

Okay, but then we need to implement the REJ/retry sequence.
I think it affects at least CMA and maybe CM.

> What would happen if the hardware simply reported that it only supported a 
> smaller MTU?

To SM? IPoIB wont work - in requires 2K MTU.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies