igt/kms_vblank: Simple harness for measuring speed of drmWaitVBlank

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 123 insertions, 0 deletions

diff --git a/tests/kms_vblank.c b/tests/kms_vblank.c
new file mode 100644
index 00000000..569390e9
--- /dev/null
+++ b/tests/kms_vblank.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright © 2015 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.
+ */
+
+/** @file kms_vblank.c
+ *
+ * This is a test of performance of drmWaitVblank.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+
+#include <drm.h>
+
+#include "ioctl_wrappers.h"
+#include "drmtest.h"
+#include "igt_aux.h"
+#include "igt_core.h"
+#include "igt_gt.h"
+#include "intel_bufmgr.h"
+#include "intel_batchbuffer.h"
+#include "intel_io.h"
+#include "intel_chipset.h"
+
+IGT_TEST_DESCRIPTION("Test speed of WaitVblank.");
+
+static double elapsed(const struct timespec *start,
+		      const struct timespec *end,
+		      int loop)
+{
+	return (1e6*(end->tv_sec - start->tv_sec) + (end->tv_nsec - start->tv_nsec)/1000)/loop;
+}
+
+static bool crtc0_active(int fd)
+{
+	union drm_wait_vblank vbl;
+
+	memset(&vbl, 0, sizeof(vbl));
+	vbl.request.type = DRM_VBLANK_RELATIVE;
+	return drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl) == 0;
+}
+
+static void query(int fd, bool busy)
+{
+	union drm_wait_vblank vbl;
+	struct timespec start, end;
+	unsigned long sq, count = 0;
+	char buf[4096];
+
+	memset(&vbl, 0, sizeof(vbl));
+
+	if (busy) {
+		vbl.request.type = DRM_VBLANK_RELATIVE | DRM_VBLANK_EVENT;
+		vbl.request.sequence = 72;
+		do_or_die(drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl));
+	}
+
+	vbl.request.type = DRM_VBLANK_RELATIVE;
+	vbl.request.sequence = 0;
+	do_or_die(drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl));
+
+	sq = vbl.reply.sequence;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	do {
+		vbl.request.type = DRM_VBLANK_RELATIVE;
+		vbl.request.sequence = 0;
+		do_or_die(drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl));
+		count++;
+	} while ((vbl.reply.sequence - sq) <= 60);
+	clock_gettime(CLOCK_MONOTONIC, &end);
+
+	igt_info("Time to query current counter (%s):		%7.3fµs\n",
+		 busy ? "busy" : "idle", elapsed(&start, &end, count));
+
+	if (busy)
+		read(fd, buf, sizeof(buf));
+}
+
+igt_main
+{
+	int fd;
+
+	igt_skip_on_simulation();
+
+	igt_fixture {
+		fd = drm_open_any();
+		igt_require(crtc0_active(fd));
+	}
+
+	igt_subtest("query-idle")
+		query(fd, false);
+
+	igt_subtest("query-busy")
+		query(fd, true);
+}