[Piglit] [PATCH] ext_timer_query/time-elapsed: Add a small test to validate GL_TIME_ELAPSED.
Eric Anholt
eric at anholt.net
Mon Oct 10 11:45:58 PDT 2011
---
tests/all.tests | 4 +
tests/spec/CMakeLists.txt | 1 +
tests/spec/ext_timer_query/CMakeLists.gl.txt | 14 ++
tests/spec/ext_timer_query/CMakeLists.txt | 1 +
tests/spec/ext_timer_query/time-elapsed.c | 254 ++++++++++++++++++++++++++
5 files changed, 274 insertions(+), 0 deletions(-)
create mode 100644 tests/spec/ext_timer_query/CMakeLists.gl.txt
create mode 100644 tests/spec/ext_timer_query/CMakeLists.txt
create mode 100644 tests/spec/ext_timer_query/time-elapsed.c
diff --git a/tests/all.tests b/tests/all.tests
index 61ba1a9..3125970 100644
--- a/tests/all.tests
+++ b/tests/all.tests
@@ -1236,6 +1236,10 @@ add_fbo_generatemipmap_extension(ext_texture_srgb, 'GL_EXT_texture_sRGB-s3tc', '
ext_texture_srgb['invalid formats'] = PlainExecTest(['arb_texture_compression-invalid-formats', 'srgb'])
ext_texture_srgb['invalid formats'].runConcurrent = True
+ext_timer_query = Group()
+spec['EXT_timer_query'] = ext_timer_query
+ext_timer_query['time-elapsed'] = concurrent_test('ext_timer_query-time-elapsed')
+
ext_transform_feedback = Group()
spec['EXT_transform_feedback'] = ext_transform_feedback
ext_transform_feedback['discard-api'] = concurrent_test('ext_transform_feedback-discard-api')
diff --git a/tests/spec/CMakeLists.txt b/tests/spec/CMakeLists.txt
index e54c1ce..a71887a 100644
--- a/tests/spec/CMakeLists.txt
+++ b/tests/spec/CMakeLists.txt
@@ -15,6 +15,7 @@ add_subdirectory (arb_transform_feedback2)
add_subdirectory (ati_envmap_bumpmap)
add_subdirectory (ext_fog_coord)
add_subdirectory (ext_packed_depth_stencil)
+add_subdirectory (ext_timer_query)
add_subdirectory (ext_transform_feedback)
add_subdirectory (nv_conditional_render)
add_subdirectory (nv_texture_barrier)
diff --git a/tests/spec/ext_timer_query/CMakeLists.gl.txt b/tests/spec/ext_timer_query/CMakeLists.gl.txt
new file mode 100644
index 0000000..f8c1700
--- /dev/null
+++ b/tests/spec/ext_timer_query/CMakeLists.gl.txt
@@ -0,0 +1,14 @@
+include_directories(
+ ${OPENGL_INCLUDE_PATH}
+ ${GLUT_INCLUDE_DIR}
+ ${piglit_SOURCE_DIR}/tests/util
+)
+
+link_libraries (
+ piglitutil
+ ${OPENGL_gl_LIBRARY}
+ ${OPENGL_glu_LIBRARY}
+ ${GLUT_glut_LIBRARY}
+)
+
+add_executable (ext_timer_query-time-elapsed time-elapsed.c)
diff --git a/tests/spec/ext_timer_query/CMakeLists.txt b/tests/spec/ext_timer_query/CMakeLists.txt
new file mode 100644
index 0000000..144a306
--- /dev/null
+++ b/tests/spec/ext_timer_query/CMakeLists.txt
@@ -0,0 +1 @@
+piglit_include_target_api()
diff --git a/tests/spec/ext_timer_query/time-elapsed.c b/tests/spec/ext_timer_query/time-elapsed.c
new file mode 100644
index 0000000..c172ac2
--- /dev/null
+++ b/tests/spec/ext_timer_query/time-elapsed.c
@@ -0,0 +1,254 @@
+/*
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "piglit-util.h"
+
+/**
+ * @file time-elapsed.c
+ *
+ * Tests that conditional rendering appropriately affects commands
+ * inside of display lists.
+ */
+
+#include <sys/time.h>
+
+int piglit_width = 128;
+int piglit_height = 128;
+int piglit_window_mode = GLUT_DOUBLE | GLUT_RGB | GLUT_ALPHA;
+
+static float
+get_time(void)
+{
+ static bool inited = false;
+ static time_t base_sec = 0;
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+
+ /* Return a value that is roughly seconds since program
+ * startup, to avoid large tv_sec reducing precision of the
+ * return value.
+ */
+ if (!inited) {
+ inited = true;
+ base_sec = tv.tv_sec;
+ }
+ tv.tv_sec -= base_sec;
+
+ return (double)tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+
+static float
+draw(GLuint q, int iters)
+{
+ float start_time, end_time;
+ int i;
+
+ start_time = get_time();
+
+ glBeginQuery(GL_TIME_ELAPSED, q);
+ for (i = 0; i < iters; i++) {
+ piglit_draw_rect(-1, -1, 2, 2);
+ }
+ glEndQuery(GL_TIME_ELAPSED);
+
+ /* This glFinish() is important, since this is used in a
+ * timing loop.
+ */
+ glFinish();
+
+ end_time = get_time();
+
+ return end_time - start_time;
+}
+
+static float
+get_gpu_time(GLuint q)
+{
+ GLint64EXT elapsed;
+
+ glGetQueryObjecti64vEXT(q, GL_QUERY_RESULT, &elapsed);
+
+ return elapsed / 1000.0 / 1000.0 / 1000.0;
+}
+
+enum piglit_result
+piglit_display(void)
+{
+ bool pass = true;
+ float green[4] = {0.0, 1.0, 0.0, 0.0};
+ GLuint q;
+ int iters;
+ int num_results = 5;
+ float cpu_time[num_results];
+ float gpu_time[num_results];
+ float delta[num_results];
+ float cpu_time_mean;
+ float delta_mean, delta_stddev;
+ float cpu_overhead;
+ float t, t_cutoff;
+ int i;
+
+ glColor4f(0.0, 1.0, 0.0, 0.0);
+ glGenQueries(1, &q);
+
+ /* Prime the drawing pipe before we start measuring time,
+ * since the first draw call is likely to be slower than all
+ * others.
+ */
+ draw(q, 1);
+
+ /* Figure out some baseline difference between GPU time
+ * elapsed and CPU time elapsed for a single draw call (CPU
+ * overhead of timer query and glFinish()).
+ *
+ * Note that this doesn't take into account any extra CPU time
+ * elapsed from start to finish if multiple batchbuffers are
+ * accumulated by the driver in getting to our 1/10th of a
+ * second elapsed time goal, and some other client sneaks
+ * rendering in in between those batches.
+ *
+ * Part of the rendering size being relatively large is to
+ * hopefully avoid that, though it might be better to have
+ * some time-consuming shader with a single draw call instead.
+ */
+ cpu_overhead = 0;
+ for (i = 0; i < num_results; i++) {
+ cpu_time[i] = draw(q, 1);
+ gpu_time[i] = get_gpu_time(q);
+
+ cpu_overhead += cpu_time[i] - gpu_time[i];
+ }
+ cpu_overhead /= num_results;
+
+ /* Find a number of draw calls that takes about 1/10th of a
+ * second.
+ */
+retry:
+ for (iters = 1; ; iters *= 2) {
+ if (draw(q, iters) > 0.1)
+ break;
+ }
+
+ /* Now, do several runs like this so we can determine if the
+ * timer matches up with wall time.
+ */
+ for (i = 0; i < num_results; i++) {
+ cpu_time[i] = draw(q, iters);
+ gpu_time[i] = get_gpu_time(q);
+ }
+
+ cpu_time_mean = 0;
+ delta_mean = 0;
+ for (i = 0; i < num_results; i++) {
+ delta[i] = cpu_time[i] - cpu_overhead - gpu_time[i];
+ cpu_time_mean += cpu_time[i];
+ delta_mean += delta[i];
+ }
+ cpu_time_mean /= num_results;
+ delta_mean /= num_results;
+
+ /* There's some risk of our "get to 0.1 seconds" loop deciding
+ * that a small number of iters was sufficient if we got
+ * scheduled out for a while. Re-run if so.
+ *
+ * We wouldn't have that problem if we could rely on the GPU
+ * time elapsed query, but that's the thing we're testing.
+ */
+ if (cpu_time_mean < 0.05)
+ goto retry;
+
+ /* Calculate stddevs. */
+ delta_stddev = 0;
+ for (i = 0; i < num_results; i++) {
+ float d = delta[i] - delta_mean;
+ delta_stddev += d * d / (num_results - 1);
+ }
+ delta_stddev = sqrt(delta_stddev);
+
+ /* Dependent t-test for paired samples.
+ *
+ * This is a good test, because we expect the two times (cpu
+ * and gpu) of the samples to be correlated, and we expect the
+ * stddev to match (since time it should arise from system
+ * variables like scheduling of other tasks and state of the
+ * caches). Unless maybe the variance of cpu time is greater
+ * than gpu time, because we may see scheduling accounted for
+ * in our CPU (wall) time, while scheduling other tasks
+ * doesn't end up counted toward our GPU time.
+ */
+ t = delta_mean / (delta_stddev / sqrt(num_results));
+
+ /* Integral of Student's t distribution for 4 degrees of
+ * freedom (num_results = 5), two-tailed (we care about
+ * difference above or below 0, not just one direction), at
+ * p = .05.
+ */
+ t_cutoff = 2.776;
+
+ /* Now test that our sampled distribution (rate of clock
+ * advance between CPU and GPU) was within expectations for a
+ * delta of 0. I actually want to be testing the likelihood
+ * that the real difference is enough that we actually care.
+ * I didn't find an easy way to account for that after a bunch
+ * of wikipedia browsing, so I'll punt on proper analysis for
+ * now and just check that the sampled delta isn't too small
+ * to care about.
+ */
+ if (t > t_cutoff && fabs(delta_mean) > .05 * cpu_time_mean) {
+ fprintf(stderr, "GPU time didn't match CPU time\n");
+ printf("Estimated CPU overhead: %f\n", cpu_overhead);
+ printf("Difference: %f secs (+/- %f secs)\n",
+ delta_mean, delta_stddev);
+ printf("t = %f\n", t);
+
+ printf("%20s %20s %20s\n",
+ "gpu_time", "cpu_time", "delta");
+ for (i = 0; i < num_results; i++) {
+ printf("%20f %20f %20f\n",
+ gpu_time[i], cpu_time[i], delta[i]);
+ }
+
+ pass = false;
+ }
+
+ pass = piglit_probe_rect_rgba(0, 0, piglit_width, piglit_height,
+ green) && pass;
+
+ piglit_present_results();
+
+ glDeleteQueries(1, &q);
+
+ return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+ if (!GLEW_VERSION_2_0) {
+ printf("Requires OpenGL 2.0\n");
+ piglit_report_result(PIGLIT_SKIP);
+ }
+
+ piglit_require_extension("GL_EXT_timer_query");
+}
--
1.7.6.3
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