From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Leonid Grossman" Subject: RE: [PATCH] TSO Reloaded Date: Fri, 6 May 2005 07:09:17 -0700 Message-ID: <200505061409.j46E9HVG020066@guinness.s2io.com> References: <20050505203052.059125eb.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Return-path: To: "'David S. Miller'" In-Reply-To: <20050505203052.059125eb.davem@davemloft.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org > -----Original Message----- > From: David S. Miller [mailto:davem@davemloft.net] > Sent: Thursday, May 05, 2005 8:31 PM > To: Leonid Grossman > Cc: netdev@oss.sgi.com > Subject: Re: [PATCH] TSO Reloaded > > On Thu, 5 May 2005 20:20:56 -0700 > "Leonid Grossman" wrote: > > > We will be testing on 10GbE NICs in the next couple weeks; will let you > > know. > > BTW - any plans for IPv6 support? > > What exactly does your NIC expect? Do you use the > NETIF_F_HW_CSUM flag to indicate generic checksumming support? > Otherwise, there is no other way to support ipv6 checksum offload > at the moment, and that is a requirement for ipv6 TSO. > > For TSO, the ipv6 header handling seems very non-trivial. > What is supposed to happen in cases where certain optional > extension headers should be present in some of the frames > but not the others? Our ASIC supports ipv6 CSUM and TSO (and header splitting) even if extension headers are present, but I suspect the majority ipv6-capable NICs will not implement this; the stack needs to query NIC header-processing capabilities (for both CSUM and TSO) and act accordingly. > > A specification of how your NIC support ipv6 TSO is necessary > in order for support to be written, see? We are planning to release the ASIC programming manual to the community fairly soon, this will provide a better view on IPv6 LSO and some other features. >Seems like you are > the most qualified person to write the support, therefore :-) > Really, it isn't that hard and you have something on which > to test whatever you write, whereas I don't. We will probably get to it sometime down the road; at the moment support for UDP LSO and receive side offloads are much higher on our list. Getting a vanilla (no support for extension headers) implementation from someone who knows the stack better than we do would be a good thing :-), I suspect this should be useful for more than one NIC vendor. Leonid