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