From: Xu Kuohai <xukuo...@huawei.com> When the bpf ring buffer is full, new events can not be recorded util the consumer consumes some events to free space. This may cause critical events to be discarded, such as in fault diagnostic, where recent events are more critical than older ones.
So add ovewrite mode for bpf ring buffer. In this mode, the new event overwrites the oldest event when the buffer is full. Xu Kuohai (4): bpf: Add overwrite mode for bpf ring buffer libbpf: ringbuf: Add overwrite ring buffer process selftests/bpf: Add test for overwrite ring buffer selftests/bpf/benchs: Add overwrite mode bench for rb-libbpf include/uapi/linux/bpf.h | 4 + kernel/bpf/ringbuf.c | 159 +++++++++++++++--- tools/include/uapi/linux/bpf.h | 4 + tools/lib/bpf/ringbuf.c | 103 +++++++++++- tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/benchs/bench_ringbufs.c | 22 ++- .../bpf/benchs/run_bench_ringbufs.sh | 4 + .../selftests/bpf/prog_tests/ringbuf.c | 74 ++++++++ .../bpf/progs/test_ringbuf_overwrite.c | 98 +++++++++++ 9 files changed, 442 insertions(+), 29 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_overwrite.c -- 2.43.0
