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From: Brendan Jackman <jackmanb@google.com>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	KP Singh <kpsingh@chromium.org>,
	Florent Revest <revest@chromium.org>,
	linux-kernel@vger.kernel.org,
	Brendan Jackman <jackmanb@google.com>
Subject: [PATCH bpf-next v2] libbpf: Expose libbpf ringbufer epoll_fd
Date: Tue, 15 Dec 2020 12:18:06 +0000
Message-ID: <20201215121816.1048557-3-jackmanb@google.com> (raw)
In-Reply-To: <20201215121816.1048557-1-jackmanb@google.com>

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>
---
Difference from v1: Added entry to libbpf.map.

 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..cde07f64771e 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(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..7be850271be6 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -348,4 +348,5 @@ LIBBPF_0.3.0 {
 		btf__new_split;
 		xsk_setup_xdp_prog;
 		xsk_socket__update_xskmap;
+                ring_buffer__epoll_fd;
 } LIBBPF_0.2.0;
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c
index 5c6522c89af1..45a36648b403 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(struct ring_buffer *rb)
+{
+	return rb->epoll_fd;
+}

base-commit: b4fe9fec51ef48011f11c2da4099f0b530449c92
--
2.29.2.576.ga3fc446d84-goog


  parent reply index

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-15 12:18 [PATCH bpf-next v4 00/11] Atomics for eBPF Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 01/11] bpf: x86: Factor out emission of ModR/M for *(reg + off) Brendan Jackman
2020-12-15 12:18 ` Brendan Jackman [this message]
2020-12-15 18:35   ` [PATCH bpf-next v2] libbpf: Expose libbpf ringbufer epoll_fd Andrii Nakryiko
2020-12-15 12:18 ` [PATCH bpf-next v5 02/11] bpf: x86: Factor out emission of REX byte Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 03/11] bpf: x86: Factor out a lookup table for some ALU opcodes Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 04/11] bpf: Rename BPF_XADD and prepare to encode other atomics in .imm Brendan Jackman
2020-12-15 14:05   ` Björn Töpel
2020-12-15 12:18 ` [PATCH bpf-next v5 05/11] bpf: Move BPF_STX reserved field check into BPF_STX verifier code Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 06/11] bpf: Add BPF_FETCH field / create atomic_fetch_add instruction Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 07/11] bpf: Add instructions for atomic_[cmp]xchg Brendan Jackman
2020-12-16  6:47   ` Yonghong Song
2020-12-15 12:18 ` [PATCH bpf-next v5 08/11] bpf: Pull out a macro for interpreting atomic ALU operations Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 09/11] bpf: Add bitwise atomic instructions Brendan Jackman
2020-12-16  6:53   ` Yonghong Song
2020-12-15 12:18 ` [PATCH bpf-next v5 10/11] bpf: Add tests for new BPF atomic operations Brendan Jackman
2020-12-15 12:18 ` [PATCH bpf-next v5 11/11] bpf: Document new atomic instructions Brendan Jackman
2020-12-16  7:08   ` Yonghong Song
2020-12-16 11:44     ` Brendan Jackman
2020-12-16 15:25       ` Yonghong Song
  -- strict thread matches above, loose matches on Subject: below --
2020-12-14 11:38 [PATCH bpf-next v2] libbpf: Expose libbpf ringbufer epoll_fd Brendan Jackman
2020-12-14 20:46 ` Daniel Borkmann
2020-12-15 10:25   ` Brendan Jackman

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