igt/perf_pmu: Measure the reference batch for all-busy-check-all

Don't rely on the timer being precise when we can sleep for a known
duration.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

1 files changed, 26 insertions, 12 deletions

diff --git a/tests/perf_pmu.c b/tests/perf_pmu.c
index b3b28965..d88287c1 100644
--- a/tests/perf_pmu.c
+++ b/tests/perf_pmu.c
@@ -288,36 +288,50 @@ all_busy_check_all(int gem_fd, const unsigned int num_engines)
 	const struct intel_execution_engine2 *e;
 	uint64_t val[num_engines];
 	int fd[num_engines];
-	igt_spin_t *spin[num_engines];
+	unsigned long slept;
+	igt_spin_t *spin = NULL;
 	unsigned int i;
 
 	i = 0;
-	fd[0] = -1;
 	for_each_engine_class_instance(fd, e) {
 		if (!gem_has_engine(gem_fd, e->class, e->instance))
 			continue;
 
-		fd[i] = open_group(I915_PMU_ENGINE_BUSY(e->class, e->instance),
-				   fd[0]);
-
-		spin[i] = igt_spin_batch_new(gem_fd, 0, e2ring(gem_fd, e), 0);
-		igt_spin_batch_set_timeout(spin[i], batch_duration_ns);
+		if (spin) {
+			struct drm_i915_gem_exec_object2 obj = {
+				.handle = spin->handle
+			};
+			struct drm_i915_gem_execbuffer2 eb = {
+				.buffer_count = 1,
+				.buffers_ptr = to_user_pointer(&obj),
+				.flags = e2ring(gem_fd, e),
+			};
+			gem_execbuf(gem_fd, &eb);
+		} else {
+			spin = igt_spin_batch_new(gem_fd, 0,
+						  e2ring(gem_fd, e), 0);
+		}
 
-		i++;
+		val[i++] = I915_PMU_ENGINE_BUSY(e->class, e->instance);
 	}
+	igt_assert(i == num_engines);
 
+	fd[0] = -1;
 	for (i = 0; i < num_engines; i++)
-		gem_sync(gem_fd, spin[i]->handle);
+		fd[i] = open_group(val[i], fd[0]);
+
+	slept = measured_usleep(batch_duration_ns / 1000);
+	igt_spin_batch_end(spin);
 
 	pmu_read_multi(fd[0], num_engines, val);
 	log_busy(fd[0], num_engines, val);
 
-	for (i = 0; i < num_engines; i++)
-		igt_spin_batch_free(gem_fd, spin[i]);
+	igt_spin_batch_free(gem_fd, spin);
 	close(fd[0]);
 
 	for (i = 0; i < num_engines; i++)
-		assert_within_epsilon(val[i], batch_duration_ns, tolerance);
+		assert_within_epsilon(val[i], slept, tolerance);
+	gem_quiescent_gpu(gem_fd);
 }
 
 static void