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authorYonghong Song <yhs@fb.com>2017-10-05 09:19:22 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-07 23:05:57 +0100
commit4bebdc7a85aa400c0222b5329861e4ad9252f1e5 (patch)
tree59151679b652bacaf545664158a85b0a4c7c75fe /include
parent020a32d9581ac824d038b0b4e24e977e3cc8589f (diff)
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')
-rw-r--r--include/uapi/linux/bpf.h10
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