1 // SPDX-License-Identifier: GPL-2.0
2 #include "tests/tests.h"
8 #include "arch-tests.h"
16 static pid_t spawn(void)
30 * Create an event group that contains both a sampled hardware
31 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
32 * wait for the hardware perf counter to overflow and generate a PMI,
33 * which triggers an event read for both of the events in the group.
35 * Since reading Intel CQM event counters requires sending SMP IPIs, the
36 * CQM pmu needs to handle the above situation gracefully, and return
37 * the last read counter value to avoid triggering a WARN_ON_ONCE() in
38 * smp_call_function_many() caused by sending IPIs from NMI context.
40 int test__intel_cqm_count_nmi_context(struct test *test __maybe_unused, int subtest __maybe_unused)
42 struct perf_evlist *evlist = NULL;
43 struct perf_evsel *evsel = NULL;
44 struct perf_event_attr pe;
45 int i, fd[2], flag, ret;
51 flag = perf_event_open_cloexec_flag();
53 evlist = perf_evlist__new();
55 pr_debug("perf_evlist__new failed\n");
59 ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL);
61 pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
66 evsel = perf_evlist__first(evlist);
68 pr_debug("perf_evlist__first failed\n");
72 memset(&pe, 0, sizeof(pe));
75 pe.type = PERF_TYPE_HARDWARE;
76 pe.config = PERF_COUNT_HW_CPU_CYCLES;
77 pe.read_format = PERF_FORMAT_GROUP;
79 pe.sample_period = 128;
80 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
84 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
86 pr_debug("failed to open event\n");
90 memset(&pe, 0, sizeof(pe));
93 pe.type = evsel->attr.type;
94 pe.config = evsel->attr.config;
96 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
98 pr_debug("failed to open event\n");
103 * Pick a power-of-two number of pages + 1 for the meta-data
104 * page (struct perf_event_mmap_page). See tools/perf/design.txt.
106 mmap_len = page_size * 65;
108 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
109 if (event == (void *)(-1)) {
110 pr_debug("failed to mmap %d\n", errno);
118 munmap(event, mmap_len);
120 for (i = 0; i < 2; i++)
126 perf_evlist__delete(evlist);