Re: [PATCH v2] RDMA/CMA: fix iWARP adapter TCP port space usage

Steve Wise
2010-06-11T21:13:12Z

Tung, Chien Tin wrote:
>> > This patch resolves the issue by allocating a kernel socket consuming
>> > the TCP port for the iWARP connection upon connection creation and
>> > freeing the socket once the iWARP connection is destroyed.
>>
>> Hasn't this exact approach been explicitly NAK'ed by David Miller?
>>
>
> Yes but this approach still is the simplest and cleanest way to solve this
> problem that I am aware of.
>
> I do want to make clear on the network resource usage. For example, if
> you run an MPI job over host TCP stack and the job creates 4 connections
> thus consuming 4 sockets. With this patch, the same job over iWARP will
> consume 4 sockets. This patch has zero impact on non-iWARP applications
> and only consumes equal amount of network resources.
>
> I would like this patch to be reconsidered for inclusion into the kernel.
>
> Chien
>
>

You can peruse this thread from 2007:

http://lkml.org/lkml/2007/8/15/174

In that thread David Miller said he would NAK this solution and even NAK
a solution where we expose the low level port allocation services and
allow RDMA/iWARP and TCP to share the port space. Thus I see no way to
resolve this issue with Dave's ACK, and maybe the RDMA contributors and
maintainers should move forward without it?

My 2 cents.