[openib-general] [PATCH ] RFC IB/cm do not track remote QPN in timewait state

[Michael S. Tsirkin]

Quoting r. Sean Hefty <mshefty at ichips.intel.com>:
> Subject: Re: [PATCH ] RFC IB/cm do not track remote QPN in timewait state
> 
> Michael S. Tsirkin wrote:
> > Hmm. But you need timewait already after you get to RTR, right?
> 
> The active side looks fine.  The passive side can enter timewait without moving 
> through RTS if it gets an RTU timeout.  I'm not sure how much going into 
> timewait really helps in this case though.
> 
> If we completely ignore timewait, what conditions are required to have a problem 
> occur?

Outstanding packets with PSNs and QP numbers coinside between the 2 connections.
Look for "Stale packet" in IB spec.

> And, can we meet those conditions if we connect over the IB CM, given 
> the CMs three-way handshake?

Hmm. We can ask user not to post sends if he rejects the REP.
Then there won't be stale packets. But is there anything in spec that
forbids this?

Maybe an extra call is better than assuming things beyond spec
requirements?

-- 
MST