1 #include "tests/tests.h"
2 #include "perf.h"
3 #include "cloexec.h"
4 #include "debug.h"
5 #include "evlist.h"
6 #include "evsel.h"
7 #include "arch-tests.h"
8
9 #include <sys/mman.h>
10 #include <string.h>
11
spawn(void)12 static pid_t spawn(void)
13 {
14 pid_t pid;
15
16 pid = fork();
17 if (pid)
18 return pid;
19
20 while(1)
21 sleep(5);
22 return 0;
23 }
24
25 /*
26 * Create an event group that contains both a sampled hardware
27 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
28 * wait for the hardware perf counter to overflow and generate a PMI,
29 * which triggers an event read for both of the events in the group.
30 *
31 * Since reading Intel CQM event counters requires sending SMP IPIs, the
32 * CQM pmu needs to handle the above situation gracefully, and return
33 * the last read counter value to avoid triggering a WARN_ON_ONCE() in
34 * smp_call_function_many() caused by sending IPIs from NMI context.
35 */
test__intel_cqm_count_nmi_context(int subtest __maybe_unused)36 int test__intel_cqm_count_nmi_context(int subtest __maybe_unused)
37 {
38 struct perf_evlist *evlist = NULL;
39 struct perf_evsel *evsel = NULL;
40 struct perf_event_attr pe;
41 int i, fd[2], flag, ret;
42 size_t mmap_len;
43 void *event;
44 pid_t pid;
45 int err = TEST_FAIL;
46
47 flag = perf_event_open_cloexec_flag();
48
49 evlist = perf_evlist__new();
50 if (!evlist) {
51 pr_debug("perf_evlist__new failed\n");
52 return TEST_FAIL;
53 }
54
55 ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL);
56 if (ret) {
57 pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
58 err = TEST_SKIP;
59 goto out;
60 }
61
62 evsel = perf_evlist__first(evlist);
63 if (!evsel) {
64 pr_debug("perf_evlist__first failed\n");
65 goto out;
66 }
67
68 memset(&pe, 0, sizeof(pe));
69 pe.size = sizeof(pe);
70
71 pe.type = PERF_TYPE_HARDWARE;
72 pe.config = PERF_COUNT_HW_CPU_CYCLES;
73 pe.read_format = PERF_FORMAT_GROUP;
74
75 pe.sample_period = 128;
76 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
77
78 pid = spawn();
79
80 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
81 if (fd[0] < 0) {
82 pr_debug("failed to open event\n");
83 goto out;
84 }
85
86 memset(&pe, 0, sizeof(pe));
87 pe.size = sizeof(pe);
88
89 pe.type = evsel->attr.type;
90 pe.config = evsel->attr.config;
91
92 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
93 if (fd[1] < 0) {
94 pr_debug("failed to open event\n");
95 goto out;
96 }
97
98 /*
99 * Pick a power-of-two number of pages + 1 for the meta-data
100 * page (struct perf_event_mmap_page). See tools/perf/design.txt.
101 */
102 mmap_len = page_size * 65;
103
104 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
105 if (event == (void *)(-1)) {
106 pr_debug("failed to mmap %d\n", errno);
107 goto out;
108 }
109
110 sleep(1);
111
112 err = TEST_OK;
113
114 munmap(event, mmap_len);
115
116 for (i = 0; i < 2; i++)
117 close(fd[i]);
118
119 kill(pid, SIGKILL);
120 wait(NULL);
121 out:
122 perf_evlist__delete(evlist);
123 return err;
124 }
125