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(e: &event, config: 0x1001e, name: "cycles");
40 event_leader_ebb_init(e: &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(e: &event));
47
48 ebb_enable_pmc_counting(pmc: 1);
49 setup_ebb_handler(standard_ebb_callee);
50 ebb_global_enable();
51
52 FAIL_IF(ebb_event_enable(e: &event));
53
54 mtspr(SPRN_PMC1, pmc_sample_period(value: 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(e: &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(child_pid: pids[i]);
99 }
100
101 return rc;
102}
103
104int main(void)
105{
106 return test_harness(multi_ebb_procs, "multi_ebb_procs");
107}
108

source code of linux/tools/testing/selftests/powerpc/pmu/ebb/multi_ebb_procs_test.c