multi_ebb_procs_test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2014, Michael Ellerman, IBM Corp.
  4 */
  5
  6#include <stdbool.h>
  7#include <stdio.h>
  8#include <stdlib.h>
  9#include <signal.h>
 10
 11#include "ebb.h"
 12
 13
 14/*
 15 * Test running multiple EBB using processes at once on a single CPU. They
 16 * should all run happily without interfering with each other.
 17 */
 18
 19static bool child_should_exit;
 20
 21static void sigint_handler(int signal)
 22{
 23	child_should_exit = true;
 24}
 25
 26struct sigaction sigint_action = {
 27	.sa_handler = sigint_handler,
 28};
 29
 30static int cycles_child(void)
 31{
 32	struct event event;
 33
 34	if (sigaction(SIGINT, &sigint_action, NULL)) {
 35		perror("sigaction");
 36		return 1;
 37	}
 38
 39	event_init_named(&event, 0x1001e, "cycles");
 40	event_leader_ebb_init(&event);
 41
 42	event.attr.exclude_kernel = 1;
 43	event.attr.exclude_hv = 1;
 44	event.attr.exclude_idle = 1;
 45
 46	FAIL_IF(event_open(&event));
 47
 48	ebb_enable_pmc_counting(1);
 49	setup_ebb_handler(standard_ebb_callee);
 50	ebb_global_enable();
 51
 52	FAIL_IF(ebb_event_enable(&event));
 53
 54	mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
 55
 56	while (!child_should_exit) {
 57		FAIL_IF(core_busy_loop());
 58		FAIL_IF(ebb_check_mmcr0());
 59	}
 60
 61	ebb_global_disable();
 62	ebb_freeze_pmcs();
 63
 64	dump_summary_ebb_state();
 65
 66	event_close(&event);
 67
 68	FAIL_IF(ebb_state.stats.ebb_count == 0);
 69
 70	return 0;
 71}
 72
 73#define NR_CHILDREN	4
 74
 75int multi_ebb_procs(void)
 76{
 77	pid_t pids[NR_CHILDREN];
 78	int rc, i;
 79
 80	SKIP_IF(!ebb_is_supported());
 81
 82	FAIL_IF(bind_to_cpu(BIND_CPU_ANY) < 0);
 83
 84	for (i = 0; i < NR_CHILDREN; i++) {
 85		pids[i] = fork();
 86		if (pids[i] == 0)
 87			exit(cycles_child());
 88	}
 89
 90	/* Have them all run for "a while" */
 91	sleep(10);
 92
 93	rc = 0;
 94	for (i = 0; i < NR_CHILDREN; i++) {
 95		/* Tell them to stop */
 96		kill(pids[i], SIGINT);
 97		/* And wait */
 98		rc |= wait_for_child(pids[i]);
 99	}
100
101	return rc;
102}
103
104int main(void)
105{
106	return test_harness(multi_ebb_procs, "multi_ebb_procs");
107}