Regards _Sugesh
> -----Original Message----- > From: Jesse Gross [mailto:je...@kernel.org] > Sent: Saturday, August 27, 2016 10:21 PM > To: Chandran, Sugesh <sugesh.chand...@intel.com> > Cc: ovs dev <dev@openvswitch.org> > Subject: Re: [RFC PATCHv6] netdev-dpdk: Enable Rx checksum offloading > feature on DPDK physical ports. > > On Sat, Aug 27, 2016 at 8:13 AM, Sugesh Chandran > <sugesh.chand...@intel.com> wrote: > > Add Rx checksum offloading feature support on DPDK physical ports. By > > default, the Rx checksum offloading is enabled if NIC supports. > > However, the checksum offloading can be turned OFF either while adding > > a new DPDK physical port to OVS or at runtime. > > > > The rx checksum offloading can be turned off by setting the parameter > > to 'false'. For eg: To disable the rx checksum offloading when adding > > a port, > > > > 'ovs-vsctl add-port br0 dpdk0 -- \ > > set Interface dpdk0 type=dpdk options:rx-checksum-offload=false' > > > > OR (to disable at run time after port is being added to OVS) > > > > 'ovs-vsctl set Interface dpdk0 options:rx-checksum-offload=false' > > > > Similarly to turn ON rx checksum offloading at run time, > > > > 'ovs-vsctl set Interface dpdk0 options:rx-checksum-offload=true' > > > > This is a RFC patch as the new checksum offload flags > 'PKT_RX_L4_CKSUM_GOOD' > > and 'PKT_RX_IP_CKSUM_GOOD' will be available only in DPDK 16.11 > > release. OVS must compile with DPDK 16.11 release to use the checksum > offloading feature. > > > > The Tx checksum offloading support is not implemented due to the > > following reasons. > > > > 1) Checksum offloading and vectorization are mutually exclusive in > > DPDK poll mode driver. Vector packet processing is turned OFF when > > checksum offloading is enabled which causes significant performance drop > at Tx side. > > > > 2) Normally, OVS generates checksum for tunnel packets in software at > > the 'tunnel push' operation, where the tunnel headers are created. > > However enabling Tx checksum offloading involves, > > > > *) Mark every packets for tx checksum offloading at 'tunnel_push' and > > recirculate. > > *) At the time of xmit, validate the same flag and instruct the NIC to do > the > > checksum calculation. In case NIC doesnt support Tx checksum offloading, > > the checksum calculation has to be done in software before sending out > the > > packets. > > > > No significant performance improvement noticed with Tx checksum > > offloading due to the e overhead of additional validations + non vector > packet processing. > > In some test scenarios, it introduces performance drop too. > > > > Rx checksum offloading still offers 8-9% of improvement on VxLAN > > tunneling decapsulation even though the SSE vector Rx function is > > disabled in DPDK poll mode driver. > > > > Signed-off-by: Sugesh Chandran <sugesh.chand...@intel.com> > > Thanks for all of the revisions! This one looks good to me. I'll look forward > to > seeing it again when the underlying DPDK support is available. > > If you want, you can include this on the patch when you send it out again > later: > Acked-by: Jesse Gross <je...@kernel.org> [Sugesh] Thanks Jesse. I will send out the patch with your ACK when DPDK support is available. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
