On Fri, May 6, 2016 at 1:13 AM, Chandran, Sugesh <sugesh.chand...@intel.com> wrote: >> -----Original Message----- >> From: Jesse Gross [mailto:je...@kernel.org] >> Sent: Friday, May 6, 2016 1:58 AM >> To: Chandran, Sugesh <sugesh.chand...@intel.com> >> Cc: pravin shelar <pshe...@ovn.org>; ovs dev <dev@openvswitch.org> >> Subject: Re: [ovs-dev] [PATCH v2] tunneling: Improving tunneling >> performance using DPDK Rx checksum offloading feature. >> >> On Thu, May 5, 2016 at 1:26 AM, Chandran, Sugesh >> <sugesh.chand...@intel.com> wrote: >> >> -----Original Message----- >> >> From: Jesse Gross [mailto:je...@kernel.org] >> >> Sent: Wednesday, May 4, 2016 10:06 PM >> >> To: Chandran, Sugesh <sugesh.chand...@intel.com> >> >> Cc: pravin shelar <pshe...@ovn.org>; ovs dev <dev@openvswitch.org> >> >> Subject: Re: [ovs-dev] [PATCH v2] tunneling: Improving tunneling >> >> performance using DPDK Rx checksum offloading feature. >> >> >> >> On Wed, May 4, 2016 at 8:58 AM, Chandran, Sugesh >> >> <sugesh.chand...@intel.com> wrote: >> >> >> -----Original Message----- >> >> >> From: Jesse Gross [mailto:je...@kernel.org] >> >> >> Sent: Thursday, April 28, 2016 4:41 PM >> >> >> To: Chandran, Sugesh <sugesh.chand...@intel.com> >> >> >> Cc: pravin shelar <pshe...@ovn.org>; ovs dev >> <dev@openvswitch.org> >> >> >> Subject: Re: [ovs-dev] [PATCH v2] tunneling: Improving tunneling >> >> >> performance using DPDK Rx checksum offloading feature. >> >> > >> >> >> That sounds great, thanks for following up. In the meantime, do >> >> >> you have any plans for transmit side checksum offloading? >> >> > [Sugesh] The vectorization on Tx side is getting disabled when DPDK >> >> > Tx >> >> checksum offload is enabled. This causes performance drop in OVS. >> >> > However We don’t find any such impact when enabling Rx checksum >> >> offloading(though this disables Rx vectorization). >> >> >> >> OK, I see. Does the drop in throughput cause performance to go below >> >> the baseline even for UDP tunnels with checksum traffic? (I guess >> >> small and large packets might have different results here.) Or is it >> >> that it reduce performance for unrelated traffic? If it's the latter >> >> case, can we find a way to use offloading conditionally? >> > [Sugesh] We tested for 64 byte UDP packet stream and found that the >> > performance is better when the offloading is turned off. This is for any >> traffic through the port. >> > DPDK doesn’t support conditional offloading for now. >> > In other words DPDK can't do selective vector packet processing on a port. >> > As far as I know there are some technical difficulties to enable >> > offload + vectorization together in DPDK. >> >> My guess is the results might be different for larger packets since those >> cases >> will stress checksumming more and rx/tx routines less. >> >> In any case, I think this is an area that is worthwhile to continue >> investigating. >> My expectation is that tunneled packets with outer UDP checksums will be a >> use case that is hit increasingly frequently with OVS DPDK - for example, OVN >> will likely start exercising this soon. > [Sugesh]Totally agreed, I will do PHY-PHY, PHY-TUNNEL-PHY tests with > different size traffic > streams(64 Byte, 512, 1024, 1500) when checksum enabled/disabled and see the > impact. > Is there any other traffic pattern/tests that we have to consider?
I think that should cover it pretty well. Thanks a lot! _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
