1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <inttypes.h>
4#include <unistd.h>
5#include <stdlib.h>
6#include <signal.h>
7#include <sys/mman.h>
8#include <linux/string.h>
9
10#include "tests.h"
11#include "util/debug.h"
12#include "util/evsel.h"
13#include "util/evlist.h"
14#include "util/cpumap.h"
15#include "util/mmap.h"
16#include "util/sample.h"
17#include "util/thread_map.h"
18#include <perf/evlist.h>
19#include <perf/mmap.h>
20
21#define NR_LOOPS 10000000
22
23/*
24 * This test will open software clock events (cpu-clock, task-clock)
25 * then check their frequency -> period conversion has no artifact of
26 * setting period to 1 forcefully.
27 */
28static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
29{
30 int i, err = -1;
31 volatile int tmp = 0;
32 u64 total_periods = 0;
33 int nr_samples = 0;
34 char sbuf[STRERR_BUFSIZE];
35 union perf_event *event;
36 struct evsel *evsel;
37 struct evlist *evlist;
38 struct perf_event_attr attr = {
39 .type = PERF_TYPE_SOFTWARE,
40 .config = clock_id,
41 .sample_type = PERF_SAMPLE_PERIOD,
42 .exclude_kernel = 1,
43 .disabled = 1,
44 .freq = 1,
45 };
46 struct perf_cpu_map *cpus = NULL;
47 struct perf_thread_map *threads = NULL;
48 struct mmap *md;
49
50 attr.sample_freq = 500;
51
52 evlist = evlist__new();
53 if (evlist == NULL) {
54 pr_debug("evlist__new\n");
55 return -1;
56 }
57
58 evsel = evsel__new(&attr);
59 if (evsel == NULL) {
60 pr_debug("evsel__new\n");
61 goto out_delete_evlist;
62 }
63 evlist__add(evlist, evsel);
64
65 cpus = perf_cpu_map__new_any_cpu();
66 threads = thread_map__new_by_tid(getpid());
67 if (!cpus || !threads) {
68 err = -ENOMEM;
69 pr_debug("Not enough memory to create thread/cpu maps\n");
70 goto out_delete_evlist;
71 }
72
73 perf_evlist__set_maps(&evlist->core, cpus, threads);
74
75 if (evlist__open(evlist)) {
76 const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
77
78 err = -errno;
79 pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
80 str_error_r(errno, sbuf, sizeof(sbuf)),
81 knob, (u64)attr.sample_freq);
82 goto out_delete_evlist;
83 }
84
85 err = evlist__mmap(evlist, 128);
86 if (err < 0) {
87 pr_debug("failed to mmap event: %d (%s)\n", errno,
88 str_error_r(errno, sbuf, sizeof(sbuf)));
89 goto out_delete_evlist;
90 }
91
92 evlist__enable(evlist);
93
94 /* collect samples */
95 for (i = 0; i < NR_LOOPS; i++)
96 tmp++;
97
98 evlist__disable(evlist);
99
100 md = &evlist->mmap[0];
101 if (perf_mmap__read_init(&md->core) < 0)
102 goto out_init;
103
104 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
105 struct perf_sample sample;
106
107 if (event->header.type != PERF_RECORD_SAMPLE)
108 goto next_event;
109
110 err = evlist__parse_sample(evlist, event, &sample);
111 if (err < 0) {
112 pr_debug("Error during parse sample\n");
113 goto out_delete_evlist;
114 }
115
116 total_periods += sample.period;
117 nr_samples++;
118next_event:
119 perf_mmap__consume(&md->core);
120 }
121 perf_mmap__read_done(&md->core);
122
123out_init:
124 if ((u64) nr_samples == total_periods) {
125 pr_debug("All (%d) samples have period value of 1!\n",
126 nr_samples);
127 err = -1;
128 }
129
130out_delete_evlist:
131 perf_cpu_map__put(cpus);
132 perf_thread_map__put(threads);
133 evlist__delete(evlist);
134 return err;
135}
136
137static int test__sw_clock_freq(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
138{
139 int ret;
140
141 ret = __test__sw_clock_freq(clock_id: PERF_COUNT_SW_CPU_CLOCK);
142 if (!ret)
143 ret = __test__sw_clock_freq(clock_id: PERF_COUNT_SW_TASK_CLOCK);
144
145 return ret;
146}
147
148DEFINE_SUITE("Software clock events period values", sw_clock_freq);
149

source code of linux/tools/perf/tests/sw-clock.c