1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2023 Isovalent */
3
4#include "vmlinux.h"
5
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_HASH);
13} hash_map_bench SEC(".maps");
14
15/* The number of slots to store times */
16#define NR_SLOTS 32
17#define NR_CPUS 256
18#define CPU_MASK (NR_CPUS-1)
19
20/* Configured by userspace */
21u64 nr_entries;
22u64 nr_loops;
23u32 __attribute__((__aligned__(8))) key[NR_CPUS];
24
25/* Filled by us */
26u64 __attribute__((__aligned__(256))) percpu_times_index[NR_CPUS];
27u64 __attribute__((__aligned__(256))) percpu_times[NR_CPUS][NR_SLOTS];
28
29static inline void patch_key(u32 i)
30{
31#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
32	key[0] = i + 1;
33#else
34	key[0] = __builtin_bswap32(i + 1);
35#endif
36	/* the rest of key is random and is configured by userspace */
37}
38
39static int lookup_callback(__u32 index, u32 *unused)
40{
41	patch_key(index);
42	return bpf_map_lookup_elem(&hash_map_bench, key) ? 0 : 1;
43}
44
45static int loop_lookup_callback(__u32 index, u32 *unused)
46{
47	return bpf_loop(nr_entries, lookup_callback, NULL, 0) ? 0 : 1;
48}
49
50SEC("fentry/" SYS_PREFIX "sys_getpgid")
51int benchmark(void *ctx)
52{
53	u32 cpu = bpf_get_smp_processor_id();
54	u32 times_index;
55	u64 start_time;
56
57	times_index = percpu_times_index[cpu & CPU_MASK] % NR_SLOTS;
58	start_time = bpf_ktime_get_ns();
59	bpf_loop(nr_loops, loop_lookup_callback, NULL, 0);
60	percpu_times[cpu & CPU_MASK][times_index] = bpf_ktime_get_ns() - start_time;
61	percpu_times_index[cpu & CPU_MASK] += 1;
62	return 0;
63}
64