1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2020 Facebook
3
4#include <linux/bpf.h>
5#include <stdint.h>
6#include <bpf/bpf_helpers.h>
7#include "bpf_misc.h"
8
9char _license[] SEC("license") = "GPL";
10
11struct {
12 __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
13 __uint(value_size, sizeof(int));
14 __uint(key_size, sizeof(int));
15} perfbuf SEC(".maps");
16
17const volatile int batch_cnt = 0;
18
19long sample_val = 42;
20long dropped __attribute__((aligned(128))) = 0;
21
22SEC("fentry/" SYS_PREFIX "sys_getpgid")
23int bench_perfbuf(void *ctx)
24{
25 int i;
26
27 for (i = 0; i < batch_cnt; i++) {
28 if (bpf_perf_event_output(ctx, &perfbuf, BPF_F_CURRENT_CPU,
29 &sample_val, sizeof(sample_val)))
30 __sync_add_and_fetch(&dropped, 1);
31 }
32 return 0;
33}
34

source code of linux/tools/testing/selftests/bpf/progs/perfbuf_bench.c