libperf: Add tests_mmap_cpus test

// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE // needed for sched.h to get sched_[gs]etaffinity and CPU_(ZERO,SET)

#include <sched.h>

#include <stdio.h>

#include <stdarg.h>

#include <unistd.h>

	return 0;

}

static int test_mmap_cpus(void)

{

	struct perf_evlist *evlist;

	struct perf_evsel *evsel;

	struct perf_mmap *map;

	struct perf_cpu_map *cpus;

	struct perf_event_attr attr = {

		.type             = PERF_TYPE_TRACEPOINT,

		.sample_period    = 1,

		.wakeup_watermark = 1,

		.disabled         = 1,

	};

	cpu_set_t saved_mask;

	char path[PATH_MAX];

	int id, err, cpu, tmp;

	union perf_event *event;

	int count = 0;

	snprintf(path, PATH_MAX, "%s/kernel/debug/tracing/events/syscalls/sys_enter_prctl/id",

		 sysfs__mountpoint());

	if (filename__read_int(path, &id)) {

		fprintf(stderr, "error: failed to get tracepoint id: %s\n", path);

		return -1;

	}

	attr.config = id;

	cpus = perf_cpu_map__new(NULL);

	__T("failed to create cpus", cpus);

	evlist = perf_evlist__new();

	__T("failed to create evlist", evlist);

	evsel = perf_evsel__new(&attr);

	__T("failed to create evsel1", evsel);

	perf_evlist__add(evlist, evsel);

	perf_evlist__set_maps(evlist, cpus, NULL);

	err = perf_evlist__open(evlist);

	__T("failed to open evlist", err == 0);

	err = perf_evlist__mmap(evlist, 4);

	__T("failed to mmap evlist", err == 0);

	perf_evlist__enable(evlist);

	err = sched_getaffinity(0, sizeof(saved_mask), &saved_mask);

	__T("sched_getaffinity failed", err == 0);

	perf_cpu_map__for_each_cpu(cpu, tmp, cpus) {

		cpu_set_t mask;

		CPU_ZERO(&mask);

		CPU_SET(cpu, &mask);

		err = sched_setaffinity(0, sizeof(mask), &mask);

		__T("sched_setaffinity failed", err == 0);

		prctl(0, 0, 0, 0, 0);

	}

	err = sched_setaffinity(0, sizeof(saved_mask), &saved_mask);

	__T("sched_setaffinity failed", err == 0);

	perf_evlist__disable(evlist);

	perf_evlist__for_each_mmap(evlist, map, false) {

		if (perf_mmap__read_init(map) < 0)

			continue;

		while ((event = perf_mmap__read_event(map)) != NULL) {

			count++;

			perf_mmap__consume(map);

		}

		perf_mmap__read_done(map);

	}

	/* calls perf_evlist__munmap/perf_evlist__close */

	perf_evlist__delete(evlist);

	/*

	 * The generated prctl events should match the

	 * number of cpus or be bigger (we are system-wide).

	 */

	__T("failed count", count >= perf_cpu_map__nr(cpus));

	perf_cpu_map__put(cpus);

	return 0;

}

int main(int argc, char **argv)

{

	__T_START;

	test_stat_thread();

	test_stat_thread_enable();

	test_mmap_thread();

	test_mmap_cpus();

	__T_OK;

	return 0;