[openib-general] [PATCHv4] IPoIB CM Experimental support

[Michael S. Tsirkin]

> Quoting Roland Dreier <rdreier at cisco.com>:
> Subject: Re: [PATCHv4] IPoIB CM Experimental support
> 
>  > - Using path MTU discovery, multicast and UDP traffic to UD mode now work,
>  >   only a small number of packets is dropped.
> 
> How does this work?  What happens if I set my MTU to 8K and send a
> 8000-byte UDP message to a node that doesn't implement CM?  What
> happens if I send an 8000-byte UDP multicast?
> 
> I didn't think UDP did path MTU discovery by default...

Before packet drop, we reduce the dst mtu, so linux will start splitting
following packets to this destination.

-- 
MST