[Xen-devel] RE: Question on sg in netback tx path

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

> > If I interpret the implications of that correctly, the 'size'
> > field in the first fragment of a packet should be the size of
> > the entire packet,
> 
>   Correct.
> 
> >but then how do I tell netback how long my
> > first fragment is?
> 
>   Look at the line following the code above:
>                 first->size -= txp->size;
> 
>   This line subtract each fragment size from the "size" field in the
first
> fragment.
>   When the loop ends you will have subtracted the size of all
fragments
> and first->size will now have the actual size of the first fragment.
> 

Thanks for the clarification - all makes sense now!

James

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