1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 // Copyright (c) 2021 Google
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
7 // This should be in sync with "util/ftrace.h"
11 __uint(type, BPF_MAP_TYPE_HASH);
12 __uint(key_size, sizeof(__u64));
13 __uint(value_size, sizeof(__u64));
14 __uint(max_entries, 10000);
15 } functime SEC(".maps");
18 __uint(type, BPF_MAP_TYPE_HASH);
19 __uint(key_size, sizeof(__u32));
20 __uint(value_size, sizeof(__u8));
21 __uint(max_entries, 1);
22 } cpu_filter SEC(".maps");
25 __uint(type, BPF_MAP_TYPE_HASH);
26 __uint(key_size, sizeof(__u32));
27 __uint(value_size, sizeof(__u8));
28 __uint(max_entries, 1);
29 } task_filter SEC(".maps");
32 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
33 __uint(key_size, sizeof(__u32));
34 __uint(value_size, sizeof(__u64));
35 __uint(max_entries, NUM_BUCKET);
36 } latency SEC(".maps");
45 int BPF_PROG(func_begin)
52 key = bpf_get_current_pid_tgid();
55 __u32 cpu = bpf_get_smp_processor_id();
58 ok = bpf_map_lookup_elem(&cpu_filter, &cpu);
64 __u32 pid = key & 0xffffffff;
67 ok = bpf_map_lookup_elem(&task_filter, &pid);
72 now = bpf_ktime_get_ns();
74 // overwrite timestamp for nested functions
75 bpf_map_update_elem(&functime, &key, &now, BPF_ANY);
80 int BPF_PROG(func_end)
84 __u64 cmp_base = use_nsec ? 1 : 1000;
89 tid = bpf_get_current_pid_tgid();
91 start = bpf_map_lookup_elem(&functime, &tid);
93 __s64 delta = bpf_ktime_get_ns() - *start;
97 bpf_map_delete_elem(&functime, &tid);
102 // calculate index using delta
103 for (key = 0; key < (NUM_BUCKET - 1); key++) {
104 if (delta < (cmp_base << key))
108 hist = bpf_map_lookup_elem(&latency, &key);