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
8 char _license[] SEC("license") = "GPL";
9
10 struct {
11 __uint(type, BPF_MAP_TYPE_RINGBUF);
12 } ringbuf SEC(".maps");
13
14 const volatile int batch_cnt = 0;
15 const volatile long use_output = 0;
16
17 long sample_val = 42;
18 long dropped __attribute__((aligned(128))) = 0;
19
20 const volatile long wakeup_data_size = 0;
21
get_flags()22 static __always_inline long get_flags()
23 {
24 long sz;
25
26 if (!wakeup_data_size)
27 return 0;
28
29 sz = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA);
30 return sz >= wakeup_data_size ? BPF_RB_FORCE_WAKEUP : BPF_RB_NO_WAKEUP;
31 }
32
33 SEC("fentry/__x64_sys_getpgid")
bench_ringbuf(void * ctx)34 int bench_ringbuf(void *ctx)
35 {
36 long *sample, flags;
37 int i;
38
39 if (!use_output) {
40 for (i = 0; i < batch_cnt; i++) {
41 sample = bpf_ringbuf_reserve(&ringbuf,
42 sizeof(sample_val), 0);
43 if (!sample) {
44 __sync_add_and_fetch(&dropped, 1);
45 } else {
46 *sample = sample_val;
47 flags = get_flags();
48 bpf_ringbuf_submit(sample, flags);
49 }
50 }
51 } else {
52 for (i = 0; i < batch_cnt; i++) {
53 flags = get_flags();
54 if (bpf_ringbuf_output(&ringbuf, &sample_val,
55 sizeof(sample_val), flags))
56 __sync_add_and_fetch(&dropped, 1);
57 }
58 }
59 return 0;
60 }
61