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
19 static bool child_should_exit;
20
sigint_handler(int signal)21 static void sigint_handler(int signal)
22 {
23 child_should_exit = true;
24 }
25
26 struct sigaction sigint_action = {
27 .sa_handler = sigint_handler,
28 };
29
cycles_child(void)30 static 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
multi_ebb_procs(void)75 int multi_ebb_procs(void)
76 {
77 pid_t pids[NR_CHILDREN];
78 int cpu, rc, i;
79
80 SKIP_IF(!ebb_is_supported());
81
82 cpu = pick_online_cpu();
83 FAIL_IF(cpu < 0);
84 FAIL_IF(bind_to_cpu(cpu));
85
86 for (i = 0; i < NR_CHILDREN; i++) {
87 pids[i] = fork();
88 if (pids[i] == 0)
89 exit(cycles_child());
90 }
91
92 /* Have them all run for "a while" */
93 sleep(10);
94
95 rc = 0;
96 for (i = 0; i < NR_CHILDREN; i++) {
97 /* Tell them to stop */
98 kill(pids[i], SIGINT);
99 /* And wait */
100 rc |= wait_for_child(pids[i]);
101 }
102
103 return rc;
104 }
105
main(void)106 int main(void)
107 {
108 return test_harness(multi_ebb_procs, "multi_ebb_procs");
109 }
110