Subject: Re: [PATCH net-next v5 2/9] xen-netback: Change TX path from grant copy to mapping

From: Zoltan Kiss <[email-masked]>
Date: Mon, 24 Feb 2014 16:56:05 +0000

On 22/02/14 22:33, Zoltan Kiss wrote:
> On 18/02/14 17:40, Ian Campbell wrote:
>> +     */
>>> +    skb->pfmemalloc    = false;
>>>   }
>>>
>>>   static int xenvif_get_extras(struct xenvif *vif,
>>> @@ -1372,7 +1341,7 @@ static bool tx_credit_exceeded(struct xenvif 
>>> *vif, unsigned size)
>>
>>> @@ -1581,7 +1535,11 @@ static int xenvif_tx_submit(struct xenvif *vif)
>>>           else if (txp->flags & XEN_NETTXF_data_validated)
>>>               skb->ip_summed = CHECKSUM_UNNECESSARY;
>>>
>>> -        xenvif_fill_frags(vif, skb);
>>> +        xenvif_fill_frags(vif,
>>> +                  skb,
>>> +                  skb_shinfo(skb)->destructor_arg ?
>>> +                  pending_idx :
>>> +                  INVALID_PENDING_IDX
>>
>> Couldn't xenvif_fill_frags calculate the 3rd argument itself given that
>> it has skb in hand.
> We still have to pass pending_idx, as it is no longer in skb->data. I 
> have plans (I've already prototyped it, actually) to move that 
> pending_idx from skb->data to skb->cb, if that happens, this won't be 
> necessary.
> On the other hand, it makes more sense just to just pass pending_idx, 
> and in fill_frags we can decide based on destructor_arg whether do we 
> need it or not.
Actually, I've just moved the skb->cb patch to the beginning of this 
series, so we can completely omit that new parameter from fill_frags.

Zoli