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 litmus tests validating all the memory orderings and locking is correct; - patch #3 is an optional patch that generalizes verifier's reference tracking machinery to capture type of reference; - patch #4 adds libbpf consumer implementation for BPF ringbuf; - path #5 adds selftest, both for single BPF ring buf use case, as well as using it with array/hash of maps; - patch #6 adds extensive benchmarks and provide some analysis in commit message, it build upon selftests/bpf's bench runner. [0] https://docs.google.com/presentation/d/18ITdg77Bj6YDOH2LghxrnFxiPWe0fAqcmJY95t_qr0w Cc: Paul E. McKenney <paulmck@xxxxxxxxxx> Cc: Jonathan Lemon <jonathan.lemon@xxxxxxxxx> Andrii Nakryiko (6): bpf: implement BPF ring buffer and verifier support for it tools/memory-model: add BPF ringbuf MPSC litmus tests bpf: track reference type in verifier libbpf: add BPF ring buffer support selftests/bpf: add BPF ringbuf selftests bpf: add BPF ringbuf and perf buffer benchmarks include/linux/bpf.h | 12 + include/linux/bpf_types.h | 1 + include/linux/bpf_verifier.h | 12 + include/uapi/linux/bpf.h | 33 +- kernel/bpf/Makefile | 2 +- kernel/bpf/helpers.c | 8 + kernel/bpf/ringbuf.c | 409 ++++++++++++ kernel/bpf/syscall.c | 12 + kernel/bpf/verifier.c | 252 ++++++-- kernel/trace/bpf_trace.c | 8 + tools/include/uapi/linux/bpf.h | 33 +- tools/lib/bpf/Build | 2 +- tools/lib/bpf/libbpf.h | 20 + tools/lib/bpf/libbpf.map | 4 + tools/lib/bpf/libbpf_probes.c | 5 + tools/lib/bpf/ringbuf.c | 264 ++++++++ .../litmus-tests/mpsc-rb+1p1c+bounded.litmus | 92 +++ .../litmus-tests/mpsc-rb+1p1c+unbound.litmus | 83 +++ .../litmus-tests/mpsc-rb+2p1c+bounded.litmus | 152 +++++ .../litmus-tests/mpsc-rb+2p1c+unbound.litmus | 137 ++++ tools/testing/selftests/bpf/Makefile | 5 +- tools/testing/selftests/bpf/bench.c | 18 + .../selftests/bpf/benchs/bench_ringbufs.c | 593 ++++++++++++++++++ .../bpf/benchs/run_bench_ringbufs.sh | 61 ++ .../selftests/bpf/prog_tests/ringbuf.c | 101 +++ .../selftests/bpf/prog_tests/ringbuf_multi.c | 102 +++ .../selftests/bpf/progs/perfbuf_bench.c | 33 + .../selftests/bpf/progs/ringbuf_bench.c | 45 ++ .../selftests/bpf/progs/test_ringbuf.c | 63 ++ .../selftests/bpf/progs/test_ringbuf_multi.c | 77 +++ 30 files changed, 2584 insertions(+), 55 deletions(-) create mode 100644 kernel/bpf/ringbuf.c create mode 100644 tools/lib/bpf/ringbuf.c create mode 100644 tools/memory-model/litmus-tests/mpsc-rb+1p1c+bounded.litmus create mode 100644 tools/memory-model/litmus-tests/mpsc-rb+1p1c+unbound.litmus create mode 100644 tools/memory-model/litmus-tests/mpsc-rb+2p1c+bounded.litmus create mode 100644 tools/memory-model/litmus-tests/mpsc-rb+2p1c+unbound.litmus create mode 100644 tools/testing/selftests/bpf/benchs/bench_ringbufs.c create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh create mode 100644 tools/testing/selftests/bpf/prog_tests/ringbuf.c create mode 100644 tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c create mode 100644 tools/testing/selftests/bpf/progs/perfbuf_bench.c create mode 100644 tools/testing/selftests/bpf/progs/ringbuf_bench.c create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_multi.c -- 2.24.1
