Hello, I'm trying to get some additional performance out of XDP on the i40e driver (under kernel 5.0.7, Fedora 28) by adjusting the queues to be one per desired core. I have several cores isolated for network traffic, so I'm adjusting the queues to be one per isolated core (with IRQ adjustments to match) as opposed to the default of one per online core. I've noticed that when I adjust the number of queues down, I see packet loss proportional to the number of queues missing. For example, if I drop the queues from the default of 36 down to 34, I see ~6% packet loss. Using the trace_pipe, I've managed to confirm that my program is successfully calling bpf_redirect_map() for all of the packet (no losst). I found the xdp_monitor tutorial[1] and ran it, and it shows the loss showing up as XDP_REDIRECT errors (which I believe means the raw_tracepoint xdp:xdp_redirect_map_err). At this point, I'm a bit stuck on how to proceed further to determine what is causing the redirect error and where the packet is being dropped. Any help in pointing me in the right direction for debugging techniques would be greatly appreciated. Thanks! --Zvi [1]: https://github.com/xdp-project/xdp-tutorial/blob/master/tracing02-xdp-monitor
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