Re: [igt-dev] [PATCH i-g-t 5/5] i915/pmu: Add a new test to use total_active_ticks for busyness

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

On Fri, Sep 22, 2023 at 02:52:33PM -0700, Umesh Nerlige Ramappa wrote:
>Busyness percentage can be calculated using the total-active-ticks
>counter as follows:
>
>% busyness = ((delta of xxxx-busy-ticks) * 100) / delta total-active-ticks
>
>Add a test to check busyness using this method.
>
>Note that total-active-ticks is updated only every 100 ms, so
>granularity of the busy-idle test is affected. To account for this, the
>test duration is set to a larger value for the new busyness interface.
>
>Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
>---
> tests/intel/perf_pmu.c | 77 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 77 insertions(+)
>
>diff --git a/tests/intel/perf_pmu.c b/tests/intel/perf_pmu.c
>index 5999d1e22..80182dbfa 100644
>--- a/tests/intel/perf_pmu.c
>+++ b/tests/intel/perf_pmu.c
>@@ -249,6 +249,16 @@
>  * Description: Test the i915 pmu perf interface
>  * Feature: i915 pmu perf interface, pmu
>  * Test category: Perf
>+ *
>+ * SUBTEST: busy-ticks
>+ * Description: Test the i915 v2 engine active busyness interface
>+ * Feature: i915 pmu perf interface, pmu
>+ * Test category: Perf
>+ *
>+ * SUBTEST: busy-idle-ticks
>+ * Description: Test the i915 v2 engine idle busyness interface
>+ * Feature: i915 pmu perf interface, pmu
>+ * Test category: Perf
>  */
>
> IGT_TEST_DESCRIPTION("Test the i915 pmu perf interface");
>@@ -2547,6 +2557,63 @@ static void pmu_read(int i915)
> 	close(pmu_fd);
> }
>
>+static void
>+single_ticks(int gem_fd, const intel_ctx_t *ctx,
>+	     const struct intel_execution_engine2 *e, unsigned int flags)
>+{
>+	igt_spin_t *spin;
>+	uint64_t before[2], after[2];
>+	uint64_t busy_ticks, total_active_ticks;
>+	int fd[2];
>+	uint64_t ahnd = get_reloc_ahnd(gem_fd, ctx->id);
>+	struct i915_engine_class_instance ci = {
>+		e->class,
>+		e->instance,
>+	};
>+	int gt = gem_engine_to_gt_map(gem_fd, &ci);
>+	double busy_percent;
>+	const unsigned long batch_long_duration_ns = 2000e6;
>+
>+	fd[0] = open_group(gem_fd, __I915_PMU_ENGINE_BUSY(e->class, e->instance), -1);
>+	fd[1] = open_group(gem_fd, __I915_PMU_TOTAL_ACTIVE_TICKS(gt), fd[0]);
>+
>+	if (flags & TEST_BUSY) {
>+		spin = igt_sync_spin(gem_fd, ahnd, ctx, e);
>+	} else {
>+		spin = NULL;
>+		gem_quiescent_gpu(gem_fd);
>+	}
>+
>+	pmu_read_multi(fd[0], 2, before);
>+	measured_usleep(batch_long_duration_ns / 1000);
>+	if (flags & TEST_TRAILING_IDLE)
>+		end_spin(gem_fd, spin, flags);
>+	pmu_read_multi(fd[0], 2, after);
>+
>+	end_spin(gem_fd, spin, FLAG_SYNC);
>+
>+	busy_ticks = after[0] - before[0];
>+	total_active_ticks = after[1] - before[1];
>+
>+	igt_info("BUSY: after %ld, before %ld\n", after[0], before[0]);
>+	igt_info("TOTAL: after %ld, before %ld\n", after[1], before[1]);
>+	igt_info("BUSY: delta %ld\n", busy_ticks);
>+	igt_info("TOTAL: delta %ld\n", total_active_ticks);
>+
>+	busy_percent = (double)(busy_ticks * 100) / (double)total_active_ticks;
>+
>+	igt_info("LOCAL: percent %f\n", busy_percent);

Will drop the igt_info in the final revision since it is for debug

Umesh