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
9 char _license[] SEC("license") = "GPL";
10
11 struct {
12 __uint(type, BPF_MAP_TYPE_RINGBUF);
13 } ringbuf SEC(".maps");
14
15 const volatile int batch_cnt = 0;
16 const volatile long use_output = 0;
17
18 long sample_val = 42;
19 long dropped __attribute__((aligned(128))) = 0;
20
21 const volatile long wakeup_data_size = 0;
22
23 static __always_inline long get_flags()
24 {
25 long sz;
26
27 if (!wakeup_data_size)
28 return 0;
29
30 sz = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA);
31 return sz >= wakeup_data_size ? BPF_RB_FORCE_WAKEUP : BPF_RB_NO_WAKEUP;
32 }
33
34 SEC("fentry/" SYS_PREFIX "sys_getpgid")
35 int bench_ringbuf(void *ctx)
36 {
37 long *sample, flags;
38 int i;
39
40 if (!use_output) {
41 for (i = 0; i < batch_cnt; i++) {
42 sample = bpf_ringbuf_reserve(&ringbuf,
43 sizeof(sample_val), 0);
44 if (!sample) {
45 __sync_add_and_fetch(&dropped, 1);
46 } else {
47 *sample = sample_val;
48 flags = get_flags();
49 bpf_ringbuf_submit(sample, flags);
50 }
51 }
52 } else {
53 for (i = 0; i < batch_cnt; i++) {
54 flags = get_flags();
55 if (bpf_ringbuf_output(&ringbuf, &sample_val,
56 sizeof(sample_val), flags))
57 __sync_add_and_fetch(&dropped, 1);
58 }
59 }
60 return 0;
61 }
62
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