1 #include "tests/tests.h"
7 #include "arch-tests.h"
14 static pid_t spawn(void)
28 * Create an event group that contains both a sampled hardware
29 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
30 * wait for the hardware perf counter to overflow and generate a PMI,
31 * which triggers an event read for both of the events in the group.
33 * Since reading Intel CQM event counters requires sending SMP IPIs, the
34 * CQM pmu needs to handle the above situation gracefully, and return
35 * the last read counter value to avoid triggering a WARN_ON_ONCE() in
36 * smp_call_function_many() caused by sending IPIs from NMI context.
38 int test__intel_cqm_count_nmi_context(int subtest __maybe_unused)
40 struct perf_evlist *evlist = NULL;
41 struct perf_evsel *evsel = NULL;
42 struct perf_event_attr pe;
43 int i, fd[2], flag, ret;
49 flag = perf_event_open_cloexec_flag();
51 evlist = perf_evlist__new();
53 pr_debug("perf_evlist__new failed\n");
57 ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL);
59 pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
64 evsel = perf_evlist__first(evlist);
66 pr_debug("perf_evlist__first failed\n");
70 memset(&pe, 0, sizeof(pe));
73 pe.type = PERF_TYPE_HARDWARE;
74 pe.config = PERF_COUNT_HW_CPU_CYCLES;
75 pe.read_format = PERF_FORMAT_GROUP;
77 pe.sample_period = 128;
78 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
82 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
84 pr_debug("failed to open event\n");
88 memset(&pe, 0, sizeof(pe));
91 pe.type = evsel->attr.type;
92 pe.config = evsel->attr.config;
94 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
96 pr_debug("failed to open event\n");
101 * Pick a power-of-two number of pages + 1 for the meta-data
102 * page (struct perf_event_mmap_page). See tools/perf/design.txt.
104 mmap_len = page_size * 65;
106 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
107 if (event == (void *)(-1)) {
108 pr_debug("failed to mmap %d\n", errno);
116 munmap(event, mmap_len);
118 for (i = 0; i < 2; i++)
124 perf_evlist__delete(evlist);