xref: /linux/tools/perf/tests/perf-time-to-tsc.c (revision 06d07429858317ded2db7986113a9e0129cd599b)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <inttypes.h>
4 #include <limits.h>
5 #include <stdbool.h>
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <linux/types.h>
9 #include <sys/prctl.h>
10 #include <perf/cpumap.h>
11 #include <perf/evlist.h>
12 #include <perf/mmap.h>
13 
14 #include "debug.h"
15 #include "parse-events.h"
16 #include "evlist.h"
17 #include "evsel.h"
18 #include "thread_map.h"
19 #include "record.h"
20 #include "tsc.h"
21 #include "mmap.h"
22 #include "tests.h"
23 #include "util/sample.h"
24 
25 /*
26  * Except x86_64/i386 and Arm64, other archs don't support TSC in perf.  Just
27  * enable the test for x86_64/i386 and Arm64 archs.
28  */
29 #if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__)
30 #define TSC_IS_SUPPORTED 1
31 #else
32 #define TSC_IS_SUPPORTED 0
33 #endif
34 
35 #define CHECK__(x) {				\
36 	while ((x) < 0) {			\
37 		pr_debug(#x " failed!\n");	\
38 		goto out_err;			\
39 	}					\
40 }
41 
42 #define CHECK_NOT_NULL__(x) {			\
43 	while ((x) == NULL) {			\
44 		pr_debug(#x " failed!\n");	\
45 		goto out_err;			\
46 	}					\
47 }
48 
test__tsc_is_supported(struct test_suite * test __maybe_unused,int subtest __maybe_unused)49 static int test__tsc_is_supported(struct test_suite *test __maybe_unused,
50 				  int subtest __maybe_unused)
51 {
52 	if (!TSC_IS_SUPPORTED) {
53 		pr_debug("Test not supported on this architecture\n");
54 		return TEST_SKIP;
55 	}
56 
57 	return TEST_OK;
58 }
59 
60 /**
61  * test__perf_time_to_tsc - test converting perf time to TSC.
62  *
63  * This function implements a test that checks that the conversion of perf time
64  * to and from TSC is consistent with the order of events.  If the test passes
65  * %0 is returned, otherwise %-1 is returned.  If TSC conversion is not
66  * supported then the test passes but " (not supported)" is printed.
67  */
test__perf_time_to_tsc(struct test_suite * test __maybe_unused,int subtest __maybe_unused)68 static int test__perf_time_to_tsc(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
69 {
70 	struct record_opts opts = {
71 		.mmap_pages	     = UINT_MAX,
72 		.user_freq	     = UINT_MAX,
73 		.user_interval	     = ULLONG_MAX,
74 		.target		     = {
75 			.uses_mmap   = true,
76 		},
77 		.sample_time	     = true,
78 	};
79 	struct perf_thread_map *threads = NULL;
80 	struct perf_cpu_map *cpus = NULL;
81 	struct evlist *evlist = NULL;
82 	struct evsel *evsel = NULL;
83 	int err = TEST_FAIL, ret, i;
84 	const char *comm1, *comm2;
85 	struct perf_tsc_conversion tc;
86 	struct perf_event_mmap_page *pc;
87 	union perf_event *event;
88 	u64 test_tsc, comm1_tsc, comm2_tsc;
89 	u64 test_time, comm1_time = 0, comm2_time = 0;
90 	struct mmap *md;
91 
92 
93 	threads = thread_map__new(-1, getpid(), UINT_MAX);
94 	CHECK_NOT_NULL__(threads);
95 
96 	cpus = perf_cpu_map__new_online_cpus();
97 	CHECK_NOT_NULL__(cpus);
98 
99 	evlist = evlist__new();
100 	CHECK_NOT_NULL__(evlist);
101 
102 	perf_evlist__set_maps(&evlist->core, cpus, threads);
103 
104 	CHECK__(parse_event(evlist, "cycles:u"));
105 
106 	evlist__config(evlist, &opts, NULL);
107 
108 	/* For hybrid "cycles:u", it creates two events */
109 	evlist__for_each_entry(evlist, evsel) {
110 		evsel->core.attr.comm = 1;
111 		evsel->core.attr.disabled = 1;
112 		evsel->core.attr.enable_on_exec = 0;
113 	}
114 
115 	ret = evlist__open(evlist);
116 	if (ret < 0) {
117 		if (ret == -ENOENT)
118 			err = TEST_SKIP;
119 		else
120 			pr_debug("evlist__open() failed\n");
121 		goto out_err;
122 	}
123 
124 	CHECK__(evlist__mmap(evlist, UINT_MAX));
125 
126 	pc = evlist->mmap[0].core.base;
127 	ret = perf_read_tsc_conversion(pc, &tc);
128 	if (ret) {
129 		if (ret == -EOPNOTSUPP) {
130 			pr_debug("perf_read_tsc_conversion is not supported in current kernel\n");
131 			err = TEST_SKIP;
132 		}
133 		goto out_err;
134 	}
135 
136 	evlist__enable(evlist);
137 
138 	comm1 = "Test COMM 1";
139 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));
140 
141 	test_tsc = rdtsc();
142 
143 	comm2 = "Test COMM 2";
144 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));
145 
146 	evlist__disable(evlist);
147 
148 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
149 		md = &evlist->mmap[i];
150 		if (perf_mmap__read_init(&md->core) < 0)
151 			continue;
152 
153 		while ((event = perf_mmap__read_event(&md->core)) != NULL) {
154 			struct perf_sample sample;
155 
156 			if (event->header.type != PERF_RECORD_COMM ||
157 			    (pid_t)event->comm.pid != getpid() ||
158 			    (pid_t)event->comm.tid != getpid())
159 				goto next_event;
160 
161 			if (strcmp(event->comm.comm, comm1) == 0) {
162 				CHECK_NOT_NULL__(evsel = evlist__event2evsel(evlist, event));
163 				CHECK__(evsel__parse_sample(evsel, event, &sample));
164 				comm1_time = sample.time;
165 			}
166 			if (strcmp(event->comm.comm, comm2) == 0) {
167 				CHECK_NOT_NULL__(evsel = evlist__event2evsel(evlist, event));
168 				CHECK__(evsel__parse_sample(evsel, event, &sample));
169 				comm2_time = sample.time;
170 			}
171 next_event:
172 			perf_mmap__consume(&md->core);
173 		}
174 		perf_mmap__read_done(&md->core);
175 	}
176 
177 	if (!comm1_time || !comm2_time)
178 		goto out_err;
179 
180 	test_time = tsc_to_perf_time(test_tsc, &tc);
181 	comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
182 	comm2_tsc = perf_time_to_tsc(comm2_time, &tc);
183 
184 	pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
185 		 comm1_time, comm1_tsc);
186 	pr_debug("rdtsc          time %"PRIu64" tsc %"PRIu64"\n",
187 		 test_time, test_tsc);
188 	pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
189 		 comm2_time, comm2_tsc);
190 
191 	if (test_time <= comm1_time ||
192 	    test_time >= comm2_time)
193 		goto out_err;
194 
195 	if (test_tsc <= comm1_tsc ||
196 	    test_tsc >= comm2_tsc)
197 		goto out_err;
198 
199 	err = TEST_OK;
200 
201 out_err:
202 	evlist__delete(evlist);
203 	perf_cpu_map__put(cpus);
204 	perf_thread_map__put(threads);
205 	return err;
206 }
207 
208 static struct test_case time_to_tsc_tests[] = {
209 	TEST_CASE_REASON("TSC support", tsc_is_supported,
210 			 "This architecture does not support"),
211 	TEST_CASE_REASON("Perf time to TSC", perf_time_to_tsc,
212 			 "perf_read_tsc_conversion is not supported"),
213 	{ .name = NULL, }
214 };
215 
216 struct test_suite suite__perf_time_to_tsc = {
217 	.desc = "Convert perf time to TSC",
218 	.test_cases = time_to_tsc_tests,
219 };
220