On Wed, 10 Jul 2024 at 12:07, Srivats P <pstavirs@xxxxxxxxx> wrote: > > > > What is the expected performance for AF_XDP txpnly in zero-copy and copy modes? > > > > > > With Kernel 6.5.0 and the same ixgbe driver, this is what we see - > > > > > > ZC mode: 4.3Mpps > > > Copy mode: 3.3Mpps > > > > > > This doesn't seem right. Shouldn't the zero copy performance be MUCH higher? > > > > Zero-copy performance should be line rate for the ixgbe card, so > > somewhere around 15Mpps. SKB mode seems in the correct ballpark. Try > > pinning the app to a core the driver does not run on, or use busy-poll > > mode "-B". If you are running on a NUMA system, make sure you are > > running both driver and app on the NUMA node you have plugged your NIC > > into. > > I had forced zero-copy mode (-z) and copy mode (-c) to get the above > results. So the xsk creation would have failed if it were not zero > copy mode. Just to avoid any confusion: copy mode = skb mode for Tx. The 3Mpps seems about correct for that mode. > This is not a NUMA system - just one CPU with 8 cores, HT > disabled. Nothing else taking up CPU on the system, so I don't think > the app and the softirq would have been sharing a core. I would ask them so that this is not the case. It happens. > Unfortunately, this is at a customer - so I have asked them to try > taskset or use -B. Will update when I hear back from them. Sounds good. > Thanks Magnus! > > Srivats
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