[ofa-general] Re: IPoIB NETIF_F_SG flag for GSO

[Michael S. Tsirkin]

> Quoting Shirley Ma <xma at us.ibm.com>:
> Subject: IPoIB NETIF_F_SG flag for GSO
> 
> Hello Roland, Michael,
> 
> I tried GSO for IPoIB last year, I didn't see much BW for UD rather than some
> cpu utilization decreasement. I looked the GSO patch carefully then I found
> there are additional skb copies in skb segment. If the device supports SG, then
> the copies can be avoided. IPoIB does support SG, I am planning to enable it to
> test GSO again. I would like to know whether you have tried this before? Any
> possible issue you can think of?
> 
> Thanks
> Shirley Ma

Yes. SG currently needs csum offloading, and IPoIB does not
support that.

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MST