[ofa-general] OFED-1.3beta IPoIB testing questions

[Tziporet Koren]

Shirley Ma wrote:
> I just touch tested ofed-1.3 beta IPoIB. And found there was a kernel 
> parameter hw_csum being added in IPoIB. I have several questions here:
> 1. Why not using ethtool to set up these HW_CSUM flags?
>   
This is experimental code - Dror explained it in OFED devcon (Or sent 
you the pointer)
> 2. I haven't looked at the detailed code yet, is that possible with this 
> flag, TCP/IP will not do CSUM for HCA which has no TCP/IP offload support? 
> If so, then these packets should be limited to be IB network. Routing to 
> ethernet network, the packets would be dropped. If not, I tested IPoIB-UD, 
> why I saw 30% improvement with hw_csum set in none connectX mthca SDR 
> environment?
>   
Arbel HCA also support checksum offload - so you will see improvement in 
this HCA too.
> 3. I saw switching between IPoIB-cm and IPoIB-ud corrupted interface IP 
> address (unicast address, subnet mask, broadcast address. Anybody saw the 
> same problem?
>   
Can you give more details? We change here between CM and UD mode all the 
time.
What is the exact scenario you run?

Tziporet