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 <jackmanb@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201214113812.305274-1-jackmanb@google.com
This commit is contained in:
Brendan Jackman 2020-12-14 11:38:12 +00:00 committed by Andrii Nakryiko
parent 2e33f831fc
commit a4d2a7ad86
3 changed files with 8 additions and 0 deletions

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@ -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;

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@ -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;

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@ -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;
}