diff options
| author | Yonghong Song <yhs@fb.com> | 2017-10-05 19:19:22 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-08 01:05:57 +0300 |
| commit | 4bebdc7a85aa400c0222b5329861e4ad9252f1e5 (patch) | |
| tree | 59151679b652bacaf545664158a85b0a4c7c75fe /include/uapi | |
| parent | 020a32d9581ac824d038b0b4e24e977e3cc8589f (diff) | |
| download | linux-4bebdc7a85aa400c0222b5329861e4ad9252f1e5.tar.xz | |
bpf: add helper bpf_perf_prog_read_value
This patch adds helper bpf_perf_prog_read_cvalue for perf event based bpf
programs, to read event counter and enabled/running time.
The enabled/running time is accumulated since the perf event open.
The typical use case for perf event based bpf program is to attach itself
to a single event. In such cases, if it is desirable to get scaling factor
between two bpf invocations, users can can save the time values in a map,
and use the value from the map and the current value to calculate
the scaling factor.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/bpf.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7b57a212c7d7..5bbbec17aa5a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -649,6 +649,13 @@ union bpf_attr { * @buf: buf to fill * @buf_size: size of the buf * Return: 0 on success or negative error code + * + * int bpf_perf_prog_read_value(ctx, buf, buf_size) + * read perf prog attached perf event counter and enabled/running time + * @ctx: pointer to ctx + * @buf: buf to fill + * @buf_size: size of the buf + * Return : 0 on success or negative error code */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -706,7 +713,8 @@ union bpf_attr { FN(sk_redirect_map), \ FN(sock_map_update), \ FN(xdp_adjust_meta), \ - FN(perf_event_read_value), + FN(perf_event_read_value), \ + FN(perf_prog_read_value), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call |