On Thu, 7 Mar 2024 15:49:15 +0000 Haiyang Zhang wrote: > > > Extend 'ethtool -S' output for mana devices to include per-CPU packet > > > stats > > > > But why? You already have per queue stats. > Yes. But the q to cpu binding is dynamic, we also want the per-CPU stat > to analyze the CPU usage by counting the packets and bytes on each CPU. Dynamic is a bit of an exaggeration, right? On a well-configured system each CPU should use a single queue assigned thru XPS. And for manual debug bpftrace should serve the purpose quite well. Please note that you can't use num_present_cpus() to size stats in ethtool -S , you have to use possible_cpus(), because the retrieval of the stats is done in a multi-syscall fashion and there are no explicit lengths in the API. So you must always report all possible stats, not just currently active :(
