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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
#include "evlist.h"
#include "evsel.h"
#include "cpumap.h"
#include "parse-events.h"
#include <api/fs/fs.h>
#include "util.h"
#include "cloexec.h"
typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
{
struct perf_evlist *evlist;
struct perf_evsel *evsel;
unsigned long flags = perf_event_open_cloexec_flag();
int err = -EAGAIN, fd;
static pid_t pid = -1;
evlist = perf_evlist__new();
if (!evlist)
return -ENOMEM;
if (parse_events(evlist, str))
goto out_delete;
evsel = perf_evlist__first(evlist);
while (1) {
fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
if (fd < 0) {
if (pid == -1 && errno == EACCES) {
pid = 0;
continue;
}
goto out_delete;
}
break;
}
close(fd);
fn(evsel);
fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
if (fd < 0) {
if (errno == EINVAL)
err = -EINVAL;
goto out_delete;
}
close(fd);
err = 0;
out_delete:
perf_evlist__delete(evlist);
return err;
}
static bool perf_probe_api(setup_probe_fn_t fn)
{
const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
struct cpu_map *cpus;
int cpu, ret, i = 0;
cpus = cpu_map__new(NULL);
if (!cpus)
return false;
cpu = cpus->map[0];
cpu_map__delete(cpus);
do {
ret = perf_do_probe_api(fn, cpu, try[i++]);
if (!ret)
return true;
} while (ret == -EAGAIN && try[i]);
return false;
}
static void perf_probe_sample_identifier(struct perf_evsel *evsel)
{
evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
}
static void perf_probe_comm_exec(struct perf_evsel *evsel)
{
evsel->attr.comm_exec = 1;
}
bool perf_can_sample_identifier(void)
{
return perf_probe_api(perf_probe_sample_identifier);
}
static bool perf_can_comm_exec(void)
{
return perf_probe_api(perf_probe_comm_exec);
}
void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
{
struct perf_evsel *evsel;
bool use_sample_identifier = false;
bool use_comm_exec;
/*
* Set the evsel leader links before we configure attributes,
* since some might depend on this info.
*/
if (opts->group)
perf_evlist__set_leader(evlist);
if (evlist->cpus->map[0] < 0)
opts->no_inherit = true;
use_comm_exec = perf_can_comm_exec();
evlist__for_each(evlist, evsel) {
perf_evsel__config(evsel, opts);
if (evsel->tracking && use_comm_exec)
evsel->attr.comm_exec = 1;
}
if (evlist->nr_entries > 1) {
struct perf_evsel *first = perf_evlist__first(evlist);
evlist__for_each(evlist, evsel) {
if (evsel->attr.sample_type == first->attr.sample_type)
continue;
use_sample_identifier = perf_can_sample_identifier();
break;
}
evlist__for_each(evlist, evsel)
perf_evsel__set_sample_id(evsel, use_sample_identifier);
}
perf_evlist__set_id_pos(evlist);
}
static int get_max_rate(unsigned int *rate)
{
char path[PATH_MAX];
const char *procfs = procfs__mountpoint();
if (!procfs)
return -1;
snprintf(path, PATH_MAX,
"%s/sys/kernel/perf_event_max_sample_rate", procfs);
return filename__read_int(path, (int *) rate);
}
static int record_opts__config_freq(struct record_opts *opts)
{
bool user_freq = opts->user_freq != UINT_MAX;
unsigned int max_rate;
if (opts->user_interval != ULLONG_MAX)
opts->default_interval = opts->user_interval;
if (user_freq)
opts->freq = opts->user_freq;
/*
* User specified count overrides default frequency.
*/
if (opts->default_interval)
opts->freq = 0;
else if (opts->freq) {
opts->default_interval = opts->freq;
} else {
pr_err("frequency and count are zero, aborting\n");
return -1;
}
if (get_max_rate(&max_rate))
return 0;
/*
* User specified frequency is over current maximum.
*/
if (user_freq && (max_rate < opts->freq)) {
pr_err("Maximum frequency rate (%u) reached.\n"
"Please use -F freq option with lower value or consider\n"
"tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
max_rate);
return -1;
}
/*
* Default frequency is over current maximum.
*/
if (max_rate < opts->freq) {
pr_warning("Lowering default frequency rate to %u.\n"
"Please consider tweaking "
"/proc/sys/kernel/perf_event_max_sample_rate.\n",
max_rate);
opts->freq = max_rate;
}
return 0;
}
int record_opts__config(struct record_opts *opts)
{
return record_opts__config_freq(opts);
}
bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
{
struct perf_evlist *temp_evlist;
struct perf_evsel *evsel;
int err, fd, cpu;
bool ret = false;
pid_t pid = -1;
temp_evlist = perf_evlist__new();
if (!temp_evlist)
return false;
err = parse_events(temp_evlist, str);
if (err)
goto out_delete;
evsel = perf_evlist__last(temp_evlist);
if (!evlist || cpu_map__empty(evlist->cpus)) {
struct cpu_map *cpus = cpu_map__new(NULL);
cpu = cpus ? cpus->map[0] : 0;
cpu_map__delete(cpus);
} else {
cpu = evlist->cpus->map[0];
}
while (1) {
fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
perf_event_open_cloexec_flag());
if (fd < 0) {
if (pid == -1 && errno == EACCES) {
pid = 0;
continue;
}
goto out_delete;
}
break;
}
close(fd);
ret = true;
out_delete:
perf_evlist__delete(temp_evlist);
return ret;
}
|
