Re: [PATCH v2 net-next 4/4] tcp: implement coalescing on backlog queue

[Eric Dumazet]

On 11/27/2018 01:58 PM, Neal Cardwell wrote:

> I wonder if technically perhaps the logic should skip coalescing if
> the tail or skb has the TCP_FLAG_URG bit set? It seems if skbs are
> coalesced, and some have urgent data and some do not, then the
> TCP_FLAG_URG bit will be accumulated into the tail header, but there
> will be no way to ensure the correct urgent offsets for the one or
> more skbs with urgent data are passed along.

Yes, I guess I need to fix that, thanks.

I will simply make sure both thtail->urg and th->urg are not set.

I could only test thtail->urg, but that would require copying th->urg_ptr and 
th->urg,
and quite frankly we should not spend cycles on URG stuff.