summaryrefslogtreecommitdiffstats
path: root/tools/perf/tests/sw-clock.c
blob: d88511f6072c2429f6c9956b83e3be803e780148 (plain)
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
#include <errno.h>
#include <inttypes.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/mman.h>

#include "tests.h"
#include "util/evsel.h"
#include "util/evlist.h"
#include "util/cpumap.h"
#include "util/thread_map.h"

#define NR_LOOPS  10000000

/*
 * This test will open software clock events (cpu-clock, task-clock)
 * then check their frequency -> period conversion has no artifact of
 * setting period to 1 forcefully.
 */
static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
{
	int i, err = -1;
	volatile int tmp = 0;
	u64 total_periods = 0;
	int nr_samples = 0;
	char sbuf[STRERR_BUFSIZE];
	union perf_event *event;
	struct perf_evsel *evsel;
	struct perf_evlist *evlist;
	struct perf_event_attr attr = {
		.type = PERF_TYPE_SOFTWARE,
		.config = clock_id,
		.sample_type = PERF_SAMPLE_PERIOD,
		.exclude_kernel = 1,
		.disabled = 1,
		.freq = 1,
	};
	struct cpu_map *cpus;
	struct thread_map *threads;

	attr.sample_freq = 500;

	evlist = perf_evlist__new();
	if (evlist == NULL) {
		pr_debug("perf_evlist__new\n");
		return -1;
	}

	evsel = perf_evsel__new(&attr);
	if (evsel == NULL) {
		pr_debug("perf_evsel__new\n");
		goto out_delete_evlist;
	}
	perf_evlist__add(evlist, evsel);

	cpus = cpu_map__dummy_new();
	threads = thread_map__new_by_tid(getpid());
	if (!cpus || !threads) {
		err = -ENOMEM;
		pr_debug("Not enough memory to create thread/cpu maps\n");
		goto out_free_maps;
	}

	perf_evlist__set_maps(evlist, cpus, threads);

	cpus	= NULL;
	threads = NULL;

	if (perf_evlist__open(evlist)) {
		const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";

		err = -errno;
		pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
			 str_error_r(errno, sbuf, sizeof(sbuf)),
			 knob, (u64)attr.sample_freq);
		goto out_delete_evlist;
	}

	err = perf_evlist__mmap(evlist, 128, true);
	if (err < 0) {
		pr_debug("failed to mmap event: %d (%s)\n", errno,
			 str_error_r(errno, sbuf, sizeof(sbuf)));
		goto out_delete_evlist;
	}

	perf_evlist__enable(evlist);

	/* collect samples */
	for (i = 0; i < NR_LOOPS; i++)
		tmp++;

	perf_evlist__disable(evlist);

	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
		struct perf_sample sample;

		if (event->header.type != PERF_RECORD_SAMPLE)
			goto next_event;

		err = perf_evlist__parse_sample(evlist, event, &sample);
		if (err < 0) {
			pr_debug("Error during parse sample\n");
			goto out_delete_evlist;
		}

		total_periods += sample.period;
		nr_samples++;
next_event:
		perf_evlist__mmap_consume(evlist, 0);
	}

	if ((u64) nr_samples == total_periods) {
		pr_debug("All (%d) samples have period value of 1!\n",
			 nr_samples);
		err = -1;
	}

out_free_maps:
	cpu_map__put(cpus);
	thread_map__put(threads);
out_delete_evlist:
	perf_evlist__delete(evlist);
	return err;
}

int test__sw_clock_freq(struct test *test __maybe_unused, int subtest __maybe_unused)
{
	int ret;

	ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
	if (!ret)
		ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);

	return ret;
}