From a4d2a7ad86834092b327082004ead755d2603376 Mon Sep 17 00:00:00 2001 From: Brendan Jackman Date: Mon, 14 Dec 2020 11:38:12 +0000 Subject: libbpf: Expose libbpf ring_buffer epoll_fd This provides a convenient perf ringbuf -> libbpf ringbuf migration path for users of external polling systems. It is analogous to perf_buffer__epoll_fd. Signed-off-by: Brendan Jackman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201214113812.305274-1-jackmanb@google.com --- tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/ringbuf.c | 6 ++++++ 3 files changed, 8 insertions(+) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 6909ee81113a..3c35eb401931 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -536,6 +536,7 @@ LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, ring_buffer_sample_fn sample_cb, void *ctx); LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); +LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); /* Perf buffer APIs */ struct perf_buffer; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 7c4126542e2b..1c0fd2dd233a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -346,6 +346,7 @@ LIBBPF_0.3.0 { btf__parse_split; btf__new_empty_split; btf__new_split; + ring_buffer__epoll_fd; xsk_setup_xdp_prog; xsk_socket__update_xskmap; } LIBBPF_0.2.0; diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c index 5c6522c89af1..a8f997d47adf 100644 --- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c @@ -282,3 +282,9 @@ int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms) } return cnt < 0 ? -errno : res; } + +/* Get an fd that can be used to sleep until data is available in the ring(s) */ +int ring_buffer__epoll_fd(const struct ring_buffer *rb) +{ + return rb->epoll_fd; +} -- cgit v1.2.3