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

[Michael S. Tsirkin]

Quoting r. Ralph Campbell <ralphc at pathscale.com>:
> Subject: [PATCH] change Mellanox SDP workaround to a moduleparameter
> 
> This patch changes the hardwired MTU limit of 1024 in SDP
> into a module parameter so it can be disabled for HCAs
> without the RC performance problem.
> 
> Signed-off-by: Ralph Campbell <ralphc at pathscale.com>

I thought about it some more: what happens if nodes with different
max MTU values try to connect?

My understanding of the spec:

- passive side should send REJ indicating error and passing the
  maximum MTU it supports
- active side should retry the connection with a lower MTU

Right?
By the way, this handling seems to be missing in CMA.

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies