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 
9 char _license[] SEC("license") = "GPL";
10 
11 struct {
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 */
21 u64 nr_entries;
22 u64 nr_loops;
23 u32 __attribute__((__aligned__(8))) key[NR_CPUS];
24 
25 /* Filled by us */
26 u64 __attribute__((__aligned__(256))) percpu_times_index[NR_CPUS];
27 u64 __attribute__((__aligned__(256))) percpu_times[NR_CPUS][NR_SLOTS];
28 
29 static 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 
39 static 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 
45 static int loop_lookup_callback(__u32 index, u32 *unused)
46 {
47 	return bpf_loop(nr_entries, lookup_callback, NULL, 0) ? 0 : 1;
48 }
49 
50 SEC("fentry/" SYS_PREFIX "sys_getpgid")
51 int 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