xref: /openbmc/linux/tools/perf/tests/mmap-basic.c (revision f7777dcc)
1 #include "evlist.h"
2 #include "evsel.h"
3 #include "thread_map.h"
4 #include "cpumap.h"
5 #include "tests.h"
6 
7 /*
8  * This test will generate random numbers of calls to some getpid syscalls,
9  * then establish an mmap for a group of events that are created to monitor
10  * the syscalls.
11  *
12  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
13  * sample.id field to map back to its respective perf_evsel instance.
14  *
15  * Then it checks if the number of syscalls reported as perf events by
16  * the kernel corresponds to the number of syscalls made.
17  */
18 int test__basic_mmap(void)
19 {
20 	int err = -1;
21 	union perf_event *event;
22 	struct thread_map *threads;
23 	struct cpu_map *cpus;
24 	struct perf_evlist *evlist;
25 	cpu_set_t cpu_set;
26 	const char *syscall_names[] = { "getsid", "getppid", "getpgrp",
27 					"getpgid", };
28 	pid_t (*syscalls[])(void) = { (void *)getsid, getppid, getpgrp,
29 				      (void*)getpgid };
30 #define nsyscalls ARRAY_SIZE(syscall_names)
31 	unsigned int nr_events[nsyscalls],
32 		     expected_nr_events[nsyscalls], i, j;
33 	struct perf_evsel *evsels[nsyscalls], *evsel;
34 
35 	threads = thread_map__new(-1, getpid(), UINT_MAX);
36 	if (threads == NULL) {
37 		pr_debug("thread_map__new\n");
38 		return -1;
39 	}
40 
41 	cpus = cpu_map__new(NULL);
42 	if (cpus == NULL) {
43 		pr_debug("cpu_map__new\n");
44 		goto out_free_threads;
45 	}
46 
47 	CPU_ZERO(&cpu_set);
48 	CPU_SET(cpus->map[0], &cpu_set);
49 	sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
50 	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
51 		pr_debug("sched_setaffinity() failed on CPU %d: %s ",
52 			 cpus->map[0], strerror(errno));
53 		goto out_free_cpus;
54 	}
55 
56 	evlist = perf_evlist__new();
57 	if (evlist == NULL) {
58 		pr_debug("perf_evlist__new\n");
59 		goto out_free_cpus;
60 	}
61 
62 	perf_evlist__set_maps(evlist, cpus, threads);
63 
64 	for (i = 0; i < nsyscalls; ++i) {
65 		char name[64];
66 
67 		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
68 		evsels[i] = perf_evsel__newtp("syscalls", name, i);
69 		if (evsels[i] == NULL) {
70 			pr_debug("perf_evsel__new\n");
71 			goto out_free_evlist;
72 		}
73 
74 		evsels[i]->attr.wakeup_events = 1;
75 		perf_evsel__set_sample_id(evsels[i], false);
76 
77 		perf_evlist__add(evlist, evsels[i]);
78 
79 		if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
80 			pr_debug("failed to open counter: %s, "
81 				 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
82 				 strerror(errno));
83 			goto out_close_fd;
84 		}
85 
86 		nr_events[i] = 0;
87 		expected_nr_events[i] = 1 + rand() % 127;
88 	}
89 
90 	if (perf_evlist__mmap(evlist, 128, true) < 0) {
91 		pr_debug("failed to mmap events: %d (%s)\n", errno,
92 			 strerror(errno));
93 		goto out_close_fd;
94 	}
95 
96 	for (i = 0; i < nsyscalls; ++i)
97 		for (j = 0; j < expected_nr_events[i]; ++j) {
98 			int foo = syscalls[i]();
99 			++foo;
100 		}
101 
102 	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
103 		struct perf_sample sample;
104 
105 		if (event->header.type != PERF_RECORD_SAMPLE) {
106 			pr_debug("unexpected %s event\n",
107 				 perf_event__name(event->header.type));
108 			goto out_munmap;
109 		}
110 
111 		err = perf_evlist__parse_sample(evlist, event, &sample);
112 		if (err) {
113 			pr_err("Can't parse sample, err = %d\n", err);
114 			goto out_munmap;
115 		}
116 
117 		err = -1;
118 		evsel = perf_evlist__id2evsel(evlist, sample.id);
119 		if (evsel == NULL) {
120 			pr_debug("event with id %" PRIu64
121 				 " doesn't map to an evsel\n", sample.id);
122 			goto out_munmap;
123 		}
124 		nr_events[evsel->idx]++;
125 	}
126 
127 	err = 0;
128 	list_for_each_entry(evsel, &evlist->entries, node) {
129 		if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
130 			pr_debug("expected %d %s events, got %d\n",
131 				 expected_nr_events[evsel->idx],
132 				 perf_evsel__name(evsel), nr_events[evsel->idx]);
133 			err = -1;
134 			goto out_munmap;
135 		}
136 	}
137 
138 out_munmap:
139 	perf_evlist__munmap(evlist);
140 out_close_fd:
141 	for (i = 0; i < nsyscalls; ++i)
142 		perf_evsel__close_fd(evsels[i], 1, threads->nr);
143 out_free_evlist:
144 	perf_evlist__delete(evlist);
145 out_free_cpus:
146 	cpu_map__delete(cpus);
147 out_free_threads:
148 	thread_map__delete(threads);
149 	return err;
150 }
151