xref: /linux/tools/perf/tests/perf-time-to-tsc.c (revision ec8a42e7343234802b9054874fe01810880289ce)
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 
24 #define CHECK__(x) {				\
25 	while ((x) < 0) {			\
26 		pr_debug(#x " failed!\n");	\
27 		goto out_err;			\
28 	}					\
29 }
30 
31 #define CHECK_NOT_NULL__(x) {			\
32 	while ((x) == NULL) {			\
33 		pr_debug(#x " failed!\n");	\
34 		goto out_err;			\
35 	}					\
36 }
37 
38 /**
39  * test__perf_time_to_tsc - test converting perf time to TSC.
40  *
41  * This function implements a test that checks that the conversion of perf time
42  * to and from TSC is consistent with the order of events.  If the test passes
43  * %0 is returned, otherwise %-1 is returned.  If TSC conversion is not
44  * supported then then the test passes but " (not supported)" is printed.
45  */
46 int test__perf_time_to_tsc(struct test *test __maybe_unused, int subtest __maybe_unused)
47 {
48 	struct record_opts opts = {
49 		.mmap_pages	     = UINT_MAX,
50 		.user_freq	     = UINT_MAX,
51 		.user_interval	     = ULLONG_MAX,
52 		.target		     = {
53 			.uses_mmap   = true,
54 		},
55 		.sample_time	     = true,
56 	};
57 	struct perf_thread_map *threads = NULL;
58 	struct perf_cpu_map *cpus = NULL;
59 	struct evlist *evlist = NULL;
60 	struct evsel *evsel = NULL;
61 	int err = -1, ret, i;
62 	const char *comm1, *comm2;
63 	struct perf_tsc_conversion tc;
64 	struct perf_event_mmap_page *pc;
65 	union perf_event *event;
66 	u64 test_tsc, comm1_tsc, comm2_tsc;
67 	u64 test_time, comm1_time = 0, comm2_time = 0;
68 	struct mmap *md;
69 
70 	threads = thread_map__new(-1, getpid(), UINT_MAX);
71 	CHECK_NOT_NULL__(threads);
72 
73 	cpus = perf_cpu_map__new(NULL);
74 	CHECK_NOT_NULL__(cpus);
75 
76 	evlist = evlist__new();
77 	CHECK_NOT_NULL__(evlist);
78 
79 	perf_evlist__set_maps(&evlist->core, cpus, threads);
80 
81 	CHECK__(parse_events(evlist, "cycles:u", NULL));
82 
83 	evlist__config(evlist, &opts, NULL);
84 
85 	evsel = evlist__first(evlist);
86 
87 	evsel->core.attr.comm = 1;
88 	evsel->core.attr.disabled = 1;
89 	evsel->core.attr.enable_on_exec = 0;
90 
91 	CHECK__(evlist__open(evlist));
92 
93 	CHECK__(evlist__mmap(evlist, UINT_MAX));
94 
95 	pc = evlist->mmap[0].core.base;
96 	ret = perf_read_tsc_conversion(pc, &tc);
97 	if (ret) {
98 		if (ret == -EOPNOTSUPP) {
99 			fprintf(stderr, " (not supported)");
100 			return 0;
101 		}
102 		goto out_err;
103 	}
104 
105 	evlist__enable(evlist);
106 
107 	comm1 = "Test COMM 1";
108 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));
109 
110 	test_tsc = rdtsc();
111 
112 	comm2 = "Test COMM 2";
113 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));
114 
115 	evlist__disable(evlist);
116 
117 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
118 		md = &evlist->mmap[i];
119 		if (perf_mmap__read_init(&md->core) < 0)
120 			continue;
121 
122 		while ((event = perf_mmap__read_event(&md->core)) != NULL) {
123 			struct perf_sample sample;
124 
125 			if (event->header.type != PERF_RECORD_COMM ||
126 			    (pid_t)event->comm.pid != getpid() ||
127 			    (pid_t)event->comm.tid != getpid())
128 				goto next_event;
129 
130 			if (strcmp(event->comm.comm, comm1) == 0) {
131 				CHECK__(evsel__parse_sample(evsel, event, &sample));
132 				comm1_time = sample.time;
133 			}
134 			if (strcmp(event->comm.comm, comm2) == 0) {
135 				CHECK__(evsel__parse_sample(evsel, event, &sample));
136 				comm2_time = sample.time;
137 			}
138 next_event:
139 			perf_mmap__consume(&md->core);
140 		}
141 		perf_mmap__read_done(&md->core);
142 	}
143 
144 	if (!comm1_time || !comm2_time)
145 		goto out_err;
146 
147 	test_time = tsc_to_perf_time(test_tsc, &tc);
148 	comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
149 	comm2_tsc = perf_time_to_tsc(comm2_time, &tc);
150 
151 	pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
152 		 comm1_time, comm1_tsc);
153 	pr_debug("rdtsc          time %"PRIu64" tsc %"PRIu64"\n",
154 		 test_time, test_tsc);
155 	pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
156 		 comm2_time, comm2_tsc);
157 
158 	if (test_time <= comm1_time ||
159 	    test_time >= comm2_time)
160 		goto out_err;
161 
162 	if (test_tsc <= comm1_tsc ||
163 	    test_tsc >= comm2_tsc)
164 		goto out_err;
165 
166 	err = 0;
167 
168 out_err:
169 	evlist__delete(evlist);
170 	return err;
171 }
172 
173 bool test__tsc_is_supported(void)
174 {
175 	/*
176 	 * Except x86_64/i386 and Arm64, other archs don't support TSC in perf.
177 	 * Just enable the test for x86_64/i386 and Arm64 archs.
178 	 */
179 #if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__)
180 	return true;
181 #else
182 	return false;
183 #endif
184 }
185