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 | |