xref: /linux/tools/perf/tests/mmap-basic.c (revision 3d689ed6099a1a11c38bb78aff7498e78e287e0b)
1 #include <inttypes.h>
2 /* For the CLR_() macros */
3 #include <pthread.h>
4 
5 #include "evlist.h"
6 #include "evsel.h"
7 #include "thread_map.h"
8 #include "cpumap.h"
9 #include "tests.h"
10 #include <linux/err.h>
11 #include <linux/kernel.h>
12 
13 /*
14  * This test will generate random numbers of calls to some getpid syscalls,
15  * then establish an mmap for a group of events that are created to monitor
16  * the syscalls.
17  *
18  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
19  * sample.id field to map back to its respective perf_evsel instance.
20  *
21  * Then it checks if the number of syscalls reported as perf events by
22  * the kernel corresponds to the number of syscalls made.
23  */
24 int test__basic_mmap(int subtest __maybe_unused)
25 {
26 	int err = -1;
27 	union perf_event *event;
28 	struct thread_map *threads;
29 	struct cpu_map *cpus;
30 	struct perf_evlist *evlist;
31 	cpu_set_t cpu_set;
32 	const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
33 	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
34 #define nsyscalls ARRAY_SIZE(syscall_names)
35 	unsigned int nr_events[nsyscalls],
36 		     expected_nr_events[nsyscalls], i, j;
37 	struct perf_evsel *evsels[nsyscalls], *evsel;
38 	char sbuf[STRERR_BUFSIZE];
39 
40 	threads = thread_map__new(-1, getpid(), UINT_MAX);
41 	if (threads == NULL) {
42 		pr_debug("thread_map__new\n");
43 		return -1;
44 	}
45 
46 	cpus = cpu_map__new(NULL);
47 	if (cpus == NULL) {
48 		pr_debug("cpu_map__new\n");
49 		goto out_free_threads;
50 	}
51 
52 	CPU_ZERO(&cpu_set);
53 	CPU_SET(cpus->map[0], &cpu_set);
54 	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
55 	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
56 		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
57 			 cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
58 		goto out_free_cpus;
59 	}
60 
61 	evlist = perf_evlist__new();
62 	if (evlist == NULL) {
63 		pr_debug("perf_evlist__new\n");
64 		goto out_free_cpus;
65 	}
66 
67 	perf_evlist__set_maps(evlist, cpus, threads);
68 
69 	for (i = 0; i < nsyscalls; ++i) {
70 		char name[64];
71 
72 		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
73 		evsels[i] = perf_evsel__newtp("syscalls", name);
74 		if (IS_ERR(evsels[i])) {
75 			pr_debug("perf_evsel__new\n");
76 			goto out_delete_evlist;
77 		}
78 
79 		evsels[i]->attr.wakeup_events = 1;
80 		perf_evsel__set_sample_id(evsels[i], false);
81 
82 		perf_evlist__add(evlist, evsels[i]);
83 
84 		if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
85 			pr_debug("failed to open counter: %s, "
86 				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
87 				 str_error_r(errno, sbuf, sizeof(sbuf)));
88 			goto out_delete_evlist;
89 		}
90 
91 		nr_events[i] = 0;
92 		expected_nr_events[i] = 1 + rand() % 127;
93 	}
94 
95 	if (perf_evlist__mmap(evlist, 128, true) < 0) {
96 		pr_debug("failed to mmap events: %d (%s)\n", errno,
97 			 str_error_r(errno, sbuf, sizeof(sbuf)));
98 		goto out_delete_evlist;
99 	}
100 
101 	for (i = 0; i < nsyscalls; ++i)
102 		for (j = 0; j < expected_nr_events[i]; ++j) {
103 			int foo = syscalls[i]();
104 			++foo;
105 		}
106 
107 	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
108 		struct perf_sample sample;
109 
110 		if (event->header.type != PERF_RECORD_SAMPLE) {
111 			pr_debug("unexpected %s event\n",
112 				 perf_event__name(event->header.type));
113 			goto out_delete_evlist;
114 		}
115 
116 		err = perf_evlist__parse_sample(evlist, event, &sample);
117 		if (err) {
118 			pr_err("Can't parse sample, err = %d\n", err);
119 			goto out_delete_evlist;
120 		}
121 
122 		err = -1;
123 		evsel = perf_evlist__id2evsel(evlist, sample.id);
124 		if (evsel == NULL) {
125 			pr_debug("event with id %" PRIu64
126 				 " doesn't map to an evsel\n", sample.id);
127 			goto out_delete_evlist;
128 		}
129 		nr_events[evsel->idx]++;
130 		perf_evlist__mmap_consume(evlist, 0);
131 	}
132 
133 	err = 0;
134 	evlist__for_each_entry(evlist, evsel) {
135 		if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
136 			pr_debug("expected %d %s events, got %d\n",
137 				 expected_nr_events[evsel->idx],
138 				 perf_evsel__name(evsel), nr_events[evsel->idx]);
139 			err = -1;
140 			goto out_delete_evlist;
141 		}
142 	}
143 
144 out_delete_evlist:
145 	perf_evlist__delete(evlist);
146 	cpus	= NULL;
147 	threads = NULL;
148 out_free_cpus:
149 	cpu_map__put(cpus);
150 out_free_threads:
151 	thread_map__put(threads);
152 	return err;
153 }
154