Regards _Sugesh
> -----Original Message----- > From: Olivier Matz [mailto:olivier.matz at 6wind.com] > Sent: Friday, June 3, 2016 1:43 PM > To: Chandran, Sugesh <sugesh.chandran at intel.com>; Ananyev, Konstantin > <konstantin.ananyev at intel.com>; Stephen Hemminger > <stephen at networkplumber.org> > Cc: Yuanhan Liu <yuanhan.liu at linux.intel.com>; dev at dpdk.org; Richardson, > Bruce <bruce.richardson at intel.com>; Adrien Mazarguil > <adrien.mazarguil at 6wind.com>; Tan, Jianfeng <jianfeng.tan at intel.com> > Subject: Re: [dpdk-dev] about rx checksum flags > > Hi, > > On 06/02/2016 09:42 AM, Chandran, Sugesh wrote: > >>>> Do you also suggest to drop IP checksum flags? > >>> > > > >>> > > IP checksum offload is mostly useless. If application needs to > >>> > > look at IP, it can do whole checksum in very few instructions, > >>> > > the whole header is in the same cache line as src/dst so the HW > >>> > > offload is really no > >> > help. > >>> > > > > [Sugesh] The checksum offload can boost the tunneling performance in > OVS. > > I guess the IP checksum also important as L4. In some cases, UDP > > checksum is zero and no need to validate it. But Ip checksum is > > present on all the packets and that must be validated all the time. > > At higher packet rate, the ip checksum offload can offer slight performance > improvement. What do you think?? > > > > Agree, in some situations (and this is even more true with packet types / > smartnics), the application could process without accessing the packet data if > we keep the IP cksum flags. [Sugesh] True, If that's the case, Will you considering to implement IP checksum flags as well along with L4? As you said , this will be useful when we offload packet lookup itself into the NICs(May be when using Flow director) ? > > Regards, > Olivier
