1 | #include <stdio.h> |
2 | #include <fcntl.h> |
3 | #include <stdint.h> |
4 | #include <stdlib.h> |
5 | |
6 | #include <linux/err.h> |
7 | |
8 | #include "util/ftrace.h" |
9 | #include "util/cpumap.h" |
10 | #include "util/thread_map.h" |
11 | #include "util/debug.h" |
12 | #include "util/evlist.h" |
13 | #include "util/bpf_counter.h" |
14 | |
15 | #include "util/bpf_skel/func_latency.skel.h" |
16 | |
17 | static struct func_latency_bpf *skel; |
18 | |
19 | int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace) |
20 | { |
21 | int fd, err; |
22 | int i, ncpus = 1, ntasks = 1; |
23 | struct filter_entry *func; |
24 | |
25 | if (!list_is_singular(&ftrace->filters)) { |
26 | pr_err("ERROR: %s target function(s).\n" , |
27 | list_empty(&ftrace->filters) ? "No" : "Too many" ); |
28 | return -1; |
29 | } |
30 | |
31 | func = list_first_entry(&ftrace->filters, struct filter_entry, list); |
32 | |
33 | skel = func_latency_bpf__open(); |
34 | if (!skel) { |
35 | pr_err("Failed to open func latency skeleton\n" ); |
36 | return -1; |
37 | } |
38 | |
39 | /* don't need to set cpu filter for system-wide mode */ |
40 | if (ftrace->target.cpu_list) { |
41 | ncpus = perf_cpu_map__nr(ftrace->evlist->core.user_requested_cpus); |
42 | bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus); |
43 | } |
44 | |
45 | if (target__has_task(&ftrace->target) || target__none(&ftrace->target)) { |
46 | ntasks = perf_thread_map__nr(ftrace->evlist->core.threads); |
47 | bpf_map__set_max_entries(skel->maps.task_filter, ntasks); |
48 | } |
49 | |
50 | set_max_rlimit(); |
51 | |
52 | err = func_latency_bpf__load(skel); |
53 | if (err) { |
54 | pr_err("Failed to load func latency skeleton\n" ); |
55 | goto out; |
56 | } |
57 | |
58 | if (ftrace->target.cpu_list) { |
59 | u32 cpu; |
60 | u8 val = 1; |
61 | |
62 | skel->bss->has_cpu = 1; |
63 | fd = bpf_map__fd(skel->maps.cpu_filter); |
64 | |
65 | for (i = 0; i < ncpus; i++) { |
66 | cpu = perf_cpu_map__cpu(ftrace->evlist->core.user_requested_cpus, i).cpu; |
67 | bpf_map_update_elem(fd, &cpu, &val, BPF_ANY); |
68 | } |
69 | } |
70 | |
71 | if (target__has_task(&ftrace->target) || target__none(&ftrace->target)) { |
72 | u32 pid; |
73 | u8 val = 1; |
74 | |
75 | skel->bss->has_task = 1; |
76 | fd = bpf_map__fd(skel->maps.task_filter); |
77 | |
78 | for (i = 0; i < ntasks; i++) { |
79 | pid = perf_thread_map__pid(ftrace->evlist->core.threads, i); |
80 | bpf_map_update_elem(fd, &pid, &val, BPF_ANY); |
81 | } |
82 | } |
83 | |
84 | skel->bss->use_nsec = ftrace->use_nsec; |
85 | |
86 | skel->links.func_begin = bpf_program__attach_kprobe(skel->progs.func_begin, |
87 | false, func->name); |
88 | if (IS_ERR(ptr: skel->links.func_begin)) { |
89 | pr_err("Failed to attach fentry program\n" ); |
90 | err = PTR_ERR(ptr: skel->links.func_begin); |
91 | goto out; |
92 | } |
93 | |
94 | skel->links.func_end = bpf_program__attach_kprobe(skel->progs.func_end, |
95 | true, func->name); |
96 | if (IS_ERR(ptr: skel->links.func_end)) { |
97 | pr_err("Failed to attach fexit program\n" ); |
98 | err = PTR_ERR(ptr: skel->links.func_end); |
99 | goto out; |
100 | } |
101 | |
102 | /* XXX: we don't actually use this fd - just for poll() */ |
103 | return open("/dev/null" , O_RDONLY); |
104 | |
105 | out: |
106 | return err; |
107 | } |
108 | |
109 | int perf_ftrace__latency_start_bpf(struct perf_ftrace *ftrace __maybe_unused) |
110 | { |
111 | skel->bss->enabled = 1; |
112 | return 0; |
113 | } |
114 | |
115 | int perf_ftrace__latency_stop_bpf(struct perf_ftrace *ftrace __maybe_unused) |
116 | { |
117 | skel->bss->enabled = 0; |
118 | return 0; |
119 | } |
120 | |
121 | int perf_ftrace__latency_read_bpf(struct perf_ftrace *ftrace __maybe_unused, |
122 | int buckets[]) |
123 | { |
124 | int i, fd, err; |
125 | u32 idx; |
126 | u64 *hist; |
127 | int ncpus = cpu__max_cpu().cpu; |
128 | |
129 | fd = bpf_map__fd(skel->maps.latency); |
130 | |
131 | hist = calloc(ncpus, sizeof(*hist)); |
132 | if (hist == NULL) |
133 | return -ENOMEM; |
134 | |
135 | for (idx = 0; idx < NUM_BUCKET; idx++) { |
136 | err = bpf_map_lookup_elem(fd, &idx, hist); |
137 | if (err) { |
138 | buckets[idx] = 0; |
139 | continue; |
140 | } |
141 | |
142 | for (i = 0; i < ncpus; i++) |
143 | buckets[idx] += hist[i]; |
144 | } |
145 | |
146 | free(hist); |
147 | return 0; |
148 | } |
149 | |
150 | int perf_ftrace__latency_cleanup_bpf(struct perf_ftrace *ftrace __maybe_unused) |
151 | { |
152 | func_latency_bpf__destroy(skel); |
153 | return 0; |
154 | } |
155 | |