Re: [PATCH v4 bpf-next 0/5] BPF ring buffer

[Daniel Borkmann <daniel@iogearbox.net>]

On Fri, May 29, 2020 at 12:54:19AM -0700, Andrii Nakryiko wrote:
> Implement a new BPF ring buffer, as presented at BPF virtual conference ([0]).
> It presents an alternative to perf buffer, following its semantics closely,
> but allowing sharing same instance of ring buffer across multiple CPUs
> efficiently.
> 
> Most patches have extensive commentary explaining various aspects, so I'll
> keep cover letter short. Overall structure of the patch set:
> - patch #1 adds BPF ring buffer implementation to kernel and necessary
>   verifier support;
> - patch #2 adds libbpf consumer implementation for BPF ringbuf;
> - patch #3 adds selftest, both for single BPF ring buf use case, as well as
>   using it with array/hash of maps;
> - patch #4 adds extensive benchmarks and provide some analysis in commit
>   message, it builds upon selftests/bpf's bench runner.
> - patch #5 adds most of patch #1 commit message as a doc under
>   Documentation/bpf/ringbuf.rst.
> 
> Litmus tests, validating consumer/producer protocols and memory orderings,
> were moved out as discussed in [1] and are going to be posted against -rcu
> tree and put under Documentation/litmus-tests/bpf-rb.
> 
>   [0] https://docs.google.com/presentation/d/18ITdg77Bj6YDOH2LghxrnFxiPWe0fAqcmJY95t_qr0w
>   [1] https://lkml.org/lkml/2020/5/22/1011
> 
> v3->v4:
> - fix ringbuf freeing (vunmap, __free_page); verified with a trivial loop
>   creating and closing ringbuf map endlessly (Daniel);

Applied, thanks!