From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ravinandan Arakali" Subject: RE: [PATCH]NET: Add ECN support for TSO Date: Tue, 11 Jul 2006 18:45:48 -0700 Message-ID: <002201c6a554$e6af4580$4710100a@pc.s2io.com> References: <20060708.133223.35527292.davem@davemloft.net> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: , Return-path: Received: from barracuda.s2io.com ([72.1.205.138]:13524 "EHLO barracuda.mail.s2io.com") by vger.kernel.org with ESMTP id S932066AbWGLBqZ (ORCPT ); Tue, 11 Jul 2006 21:46:25 -0400 To: "'David Miller'" , In-Reply-To: <20060708.133223.35527292.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Michael/David, Thanks for the comments on LRO. The current LRO code in S2io driver is not aware of ECN. While I was trying to fix this, the first thing I encountered was to check, in the driver, if ECN is enabled for current session. To do this, I try to get hold of the socket by doing something like: tk = tcp_sk(skb->sk); if (tk->ecn_flags & TCP_ECN_OK) /* Check CE, ECE, CWR etc */ I find that skb->sk is NULL. Is this the correct way to check the per-session ECN capability ? Why is skb->sk NULL ? Thanks, Ravi -----Original Message----- From: David Miller [mailto:davem@davemloft.net] Sent: Saturday, July 08, 2006 1:32 PM To: mchan@broadcom.com Cc: ravinandan.arakali@neterion.com; herbert@gondor.apana.org.au; netdev@vger.kernel.org Subject: Re: [PATCH]NET: Add ECN support for TSO From: "Michael Chan" Date: Fri, 7 Jul 2006 18:01:34 -0700 > However, Large Receive Offload will be a different story. If > packets are accumulated in the hardware and presented to the stack > as one large packet, the stack will not be able to calculate the > cumulative NS correctly. Unless the hardware calculates the partial > NS over the LRO packet and puts it in the SKB when handing over the > packet. This is correct, LRO hardware would need to do something to make sure the nonce parity works out.