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      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 		perf_evlist__mmap_consume(evlist, 0);
    126 	}
    127 
    128 	err = 0;
    129 	list_for_each_entry(evsel, &evlist->entries, node) {
    130 		if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
    131 			pr_debug("expected %d %s events, got %d\n",
    132 				 expected_nr_events[evsel->idx],
    133 				 perf_evsel__name(evsel), nr_events[evsel->idx]);
    134 			err = -1;
    135 			goto out_munmap;
    136 		}
    137 	}
    138 
    139 out_munmap:
    140 	perf_evlist__munmap(evlist);
    141 out_close_fd:
    142 	for (i = 0; i < nsyscalls; ++i)
    143 		perf_evsel__close_fd(evsels[i], 1, threads->nr);
    144 out_free_evlist:
    145 	perf_evlist__delete(evlist);
    146 out_free_cpus:
    147 	cpu_map__delete(cpus);
    148 out_free_threads:
    149 	thread_map__delete(threads);
    150 	return err;
    151 }
    152