Daniel Borkmann <daniel@xxxxxxxxxxxxx> writes: > On 7/28/21 6:55 PM, Kumar Kartikeya Dwivedi wrote: >> This file implements some common helpers to consolidate differences in >> features and functionality between the various XDP samples and give them >> a consistent look, feel, and reporting capabilities. >> >> Some of the key features are: >> * A concise output format accompanied by helpful text explaining its >> fields. >> * An elaborate output format building upon the concise one, and folding >> out details in case of errors and staying out of view otherwise. >> * Extended reporting of redirect errors by capturing hits for each >> errno and displaying them inline (ENETDOWN, EINVAL, ENOSPC, etc.) >> to aid debugging. >> * Reporting of each xdp_exception action for all samples that use these >> helpers (XDP_ABORTED, etc.) to aid debugging. >> * Capturing per ifindex pair devmap_xmit counts for decomposing the >> total TX count per devmap redirection. >> * Ability to jump to source locations invoking tracepoints. >> * Faster retrieval of stats per polling interval using mmap'd eBPF >> array map (through .bss). >> * Printing driver names for devices redirecting packets. >> * Printing summarized total statistics for the entire session. >> * Ability to dynamically switch between concise and verbose mode, using >> SIGQUIT (Ctrl + \). >> >> The goal is sharing these helpers that most of the XDP samples implement >> in some form but differently for each, lacking in some respect compared >> to one another. >> >> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> > > Overall I think it's okay to try to streamline the individual XDP tools, but I > also tend to wonder whether we keep going beyond the original purpose of kernel > samples where the main goal is to provide small, easy to hack & stand-alone code > snippets (like in samples/seccomp ... no doubt we have it more complex in BPF > land, but still); things people can take away and extend for their purpose. A big > portion of the samples are still better off in selftests so they can be run in CI, > and those that are not should generally be simplified for developers to rip out, > modify, experiment, and build actual applications on top. FWIW the idea of improving the samples came from Jesper and myself; we've come to rely on them quite a bit for benchmarking, and our QE folks run them for testing as well. And I've lost count of the number of times I had to redo tests because something wasn't working correctly and I didn't notice that the numbers were off. Kumar took the "improve the XDP samples" idea and ran with it, and I think the result is much improved; having it be immediately obvious when something is off is a huge benefit! So while I do share your concern about expanding the samples code too much, in this instance I think it's an improvement. I've toyed with the idea of also distributing some of the XDP samples with xdp-tools so they are easier to install as standalone utilities, but I think that is a secondary concern for later. -Toke
