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-rw-r--r--tools/perf/arch/x86/tests/intel-cqm.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/tests/intel-cqm.c b/tools/perf/arch/x86/tests/intel-cqm.c
new file mode 100644
index 000000000..3ec562a2a
--- /dev/null
+++ b/tools/perf/arch/x86/tests/intel-cqm.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "tests/tests.h"
+#include "cloexec.h"
+#include "debug.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "arch-tests.h"
+#include <internal/lib.h> // page_size
+
+#include <signal.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+
+static pid_t spawn(void)
+{
+ pid_t pid;
+
+ pid = fork();
+ if (pid)
+ return pid;
+
+ while(1)
+ sleep(5);
+ return 0;
+}
+
+/*
+ * Create an event group that contains both a sampled hardware
+ * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
+ * wait for the hardware perf counter to overflow and generate a PMI,
+ * which triggers an event read for both of the events in the group.
+ *
+ * Since reading Intel CQM event counters requires sending SMP IPIs, the
+ * CQM pmu needs to handle the above situation gracefully, and return
+ * the last read counter value to avoid triggering a WARN_ON_ONCE() in
+ * smp_call_function_many() caused by sending IPIs from NMI context.
+ */
+int test__intel_cqm_count_nmi_context(struct test *test __maybe_unused, int subtest __maybe_unused)
+{
+ struct evlist *evlist = NULL;
+ struct evsel *evsel = NULL;
+ struct perf_event_attr pe;
+ int i, fd[2], flag, ret;
+ size_t mmap_len;
+ void *event;
+ pid_t pid;
+ int err = TEST_FAIL;
+
+ flag = perf_event_open_cloexec_flag();
+
+ evlist = evlist__new();
+ if (!evlist) {
+ pr_debug("perf_evlist__new failed\n");
+ return TEST_FAIL;
+ }
+
+ ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL);
+ if (ret) {
+ pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
+ err = TEST_SKIP;
+ goto out;
+ }
+
+ evsel = evlist__first(evlist);
+ if (!evsel) {
+ pr_debug("evlist__first failed\n");
+ goto out;
+ }
+
+ memset(&pe, 0, sizeof(pe));
+ pe.size = sizeof(pe);
+
+ pe.type = PERF_TYPE_HARDWARE;
+ pe.config = PERF_COUNT_HW_CPU_CYCLES;
+ pe.read_format = PERF_FORMAT_GROUP;
+
+ pe.sample_period = 128;
+ pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
+
+ pid = spawn();
+
+ fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
+ if (fd[0] < 0) {
+ pr_debug("failed to open event\n");
+ goto out;
+ }
+
+ memset(&pe, 0, sizeof(pe));
+ pe.size = sizeof(pe);
+
+ pe.type = evsel->attr.type;
+ pe.config = evsel->attr.config;
+
+ fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
+ if (fd[1] < 0) {
+ pr_debug("failed to open event\n");
+ goto out;
+ }
+
+ /*
+ * Pick a power-of-two number of pages + 1 for the meta-data
+ * page (struct perf_event_mmap_page). See tools/perf/design.txt.
+ */
+ mmap_len = page_size * 65;
+
+ event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
+ if (event == (void *)(-1)) {
+ pr_debug("failed to mmap %d\n", errno);
+ goto out;
+ }
+
+ sleep(1);
+
+ err = TEST_OK;
+
+ munmap(event, mmap_len);
+
+ for (i = 0; i < 2; i++)
+ close(fd[i]);
+
+ kill(pid, SIGKILL);
+ wait(NULL);
+out:
+ evlist__delete(evlist);
+ return err;
+}