[igt-dev] [PATCH i-g-t] test/perf: Add test to verify OA TLB invalidation

Umesh Nerlige Ramappa
2020-03-10T03:07:43Z

Run 2 polling tests back to back and compare the number of OA reports
captured. Make sure the number of reports are almost same.

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
---
tests/perf.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 97 insertions(+)

diff --git a/tests/perf.c b/tests/perf.c
index 5e818030..2394adc4 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -2265,6 +2265,97 @@ test_polling(void)
__perf_close(stream_fd);
}

+static int
+num_valid_reports_captured(struct drm_i915_perf_open_param *param)
+{
+ uint8_t buf[1024 * 1024];
+ int64_t tick_ns = 1000000000 / sysconf(_SC_CLK_TCK);
+ int64_t test_duration_ns = tick_ns * 5 * 100; /* 5 seconds */
+ int64_t start, end;
+ int num_reports = 0;
+
+ stream_fd = __perf_open(drm_fd, param, true);
+
+ igt_debug("tick length = %dns, test duration = %"PRIu64"ns\n",
+ (int)tick_ns, test_duration_ns);
+
+ start = get_time();
+ do_ioctl(stream_fd, I915_PERF_IOCTL_ENABLE, 0);
+ for (/* nop */; ((end = get_time()) - start) < test_duration_ns; /* nop */) {
+ struct pollfd pollfd = { .fd = stream_fd, .events = POLLIN };
+ struct drm_i915_perf_record_header *header;
+ int ret;
+
+ while ((ret = poll(&pollfd, 1, -1)) < 0 &&
+ errno == EINTR)
+ ;
+ igt_assert_eq(ret, 1);
+ igt_assert(pollfd.revents & POLLIN);
+
+ while ((ret = read(stream_fd, buf, sizeof(buf))) < 0 &&
+ errno == EINTR)
+ ;
+
+ /* poll checks if the tail has advanced on the OA buffer, but
+ * does not check if the reports are valid. On read, the driver
+ * checks if the reports are valid or not. if none of the
+ * reports are valid, it returns EAGAIN. EAGAIN should also
+ * suffice to show that the TLB invalidation failed, but we will
+ * try for a more concrete check. Ignore read errors here.
+ */
+ if (ret < 0)
+ continue;
+
+ for (int offset = 0; offset < ret; offset += header->size) {
+ header = (void *)(buf + offset);
+
+ if (header->type == DRM_I915_PERF_RECORD_SAMPLE) {
+ uint32_t *report = (void *)(header + 1);
+
+ if ((report[0] >> OAREPORT_REASON_SHIFT) &
+ OAREPORT_REASON_TIMER)
+ num_reports++;
+ }
+ }
+ }
+ __perf_close(stream_fd);
+
+ return num_reports;
+}
+
+static void
+gen12_test_oa_tlb_invalidate(void)
+{
+ int oa_exponent = max_oa_exponent_for_period_lte(30000000);
+ uint64_t properties[] = {
+ DRM_I915_PERF_PROP_SAMPLE_OA, true,
+
+ DRM_I915_PERF_PROP_OA_METRICS_SET, test_set->perf_oa_metrics_set,
+ DRM_I915_PERF_PROP_OA_FORMAT, test_set->perf_oa_format,
+ DRM_I915_PERF_PROP_OA_EXPONENT, oa_exponent,
+ };
+ struct drm_i915_perf_open_param param = {
+ .flags = I915_PERF_FLAG_FD_CLOEXEC |
+ I915_PERF_FLAG_DISABLED |
+ I915_PERF_FLAG_FD_NONBLOCK,
+ .num_properties = sizeof(properties) / 16,
+ .properties_ptr = to_user_pointer(properties),
+ };
+ int num_reports1, num_reports2;
+
+ /* Capture reports for 5 seconds twice and then make sure you get around
+ * the same number of reports. In the case of failure, the number of
+ * reports will vary largely since the beginning of the OA buffer
+ * will have invalid entries.
+ */
+ num_reports1 = num_valid_reports_captured(&param);
+ num_reports2 = num_valid_reports_captured(&param);
+
+ igt_debug("num_reports1 = %d, num_reports2 = %d\n", num_reports1, num_reports2);
+ igt_assert(num_reports2 > 0.95 * num_reports1);
+}
+
+
static void
test_buffer_fill(void)
{
@@ -4622,6 +4713,12 @@ igt_main
gen8_test_single_ctx_render_target_writes_a_counter();
}

+ igt_describe("Test OA TLB invalidate");
+ igt_subtest("gen12-oa-tlb-invalidate") {
+ igt_require(intel_gen(devid) >= 12);
+ gen12_test_oa_tlb_invalidate();
+ }
+
igt_describe("Measure performance for a specific context using OAR in Gen 12");
igt_subtest("gen12-unprivileged-single-ctx-counters") {
igt_require(intel_gen(devid) >= 12);
--
2.17.1