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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Test backward bit in event attribute, read ring buffer from end to
* beginning
*/
#include <evlist.h>
#include <sys/prctl.h>
#include "record.h"
#include "tests.h"
#include "debug.h"
#include "parse-events.h"
#include "util/mmap.h"
#include <errno.h>
#include <linux/string.h>
#include <perf/mmap.h>
#define NR_ITERS 111
static void testcase(void)
{
int i;
for (i = 0; i < NR_ITERS; i++) {
char proc_name[15];
snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
prctl(PR_SET_NAME, proc_name);
}
}
static int count_samples(struct evlist *evlist, int *sample_count,
int *comm_count)
{
int i;
for (i = 0; i < evlist->core.nr_mmaps; i++) {
struct mmap *map = &evlist->overwrite_mmap[i];
union perf_event *event;
perf_mmap__read_init(&map->core);
while ((event = perf_mmap__read_event(&map->core)) != NULL) {
const u32 type = event->header.type;
switch (type) {
case PERF_RECORD_SAMPLE:
(*sample_count)++;
break;
case PERF_RECORD_COMM:
(*comm_count)++;
break;
default:
pr_err("Unexpected record of type %d\n", type);
return TEST_FAIL;
}
}
perf_mmap__read_done(&map->core);
}
return TEST_OK;
}
static int do_test(struct evlist *evlist, int mmap_pages,
int *sample_count, int *comm_count)
{
int err;
char sbuf[STRERR_BUFSIZE];
err = evlist__mmap(evlist, mmap_pages);
if (err < 0) {
pr_debug("evlist__mmap: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
return TEST_FAIL;
}
evlist__enable(evlist);
testcase();
evlist__disable(evlist);
err = count_samples(evlist, sample_count, comm_count);
evlist__munmap(evlist);
return err;
}
static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
char pid[16], sbuf[STRERR_BUFSIZE];
struct evlist *evlist;
struct evsel *evsel __maybe_unused;
struct parse_events_error parse_error;
struct record_opts opts = {
.target = {
.uid = UINT_MAX,
.uses_mmap = true,
},
.freq = 0,
.mmap_pages = 256,
.default_interval = 1,
};
snprintf(pid, sizeof(pid), "%d", getpid());
pid[sizeof(pid) - 1] = '\0';
opts.target.tid = opts.target.pid = pid;
evlist = evlist__new();
if (!evlist) {
pr_debug("Not enough memory to create evlist\n");
return TEST_FAIL;
}
err = evlist__create_maps(evlist, &opts.target);
if (err < 0) {
pr_debug("Not enough memory to create thread/cpu maps\n");
goto out_delete_evlist;
}
parse_events_error__init(&parse_error);
/*
* Set backward bit, ring buffer should be writing from end. Record
* it in aux evlist
*/
err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
parse_events_error__exit(&parse_error);
if (err) {
pr_debug("Failed to parse tracepoint event, try use root\n");
ret = TEST_SKIP;
goto out_delete_evlist;
}
evlist__config(evlist, &opts, NULL);
err = evlist__open(evlist);
if (err < 0) {
pr_debug("perf_evlist__open: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
ret = TEST_FAIL;
err = do_test(evlist, opts.mmap_pages, &sample_count,
&comm_count);
if (err != TEST_OK)
goto out_delete_evlist;
if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
sample_count, comm_count);
goto out_delete_evlist;
}
evlist__close(evlist);
err = evlist__open(evlist);
if (err < 0) {
pr_debug("perf_evlist__open: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
err = do_test(evlist, 1, &sample_count, &comm_count);
if (err != TEST_OK)
goto out_delete_evlist;
ret = TEST_OK;
out_delete_evlist:
evlist__delete(evlist);
return ret;
}
DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer);
|
