benchmarks: Add a set-domain benchmark

Benchmark the overhead of changing from GTT to CPU domains and vice
versa. Effectively this measures the cost of a clflush, and how well the
driver can avoid them.

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

1 files changed, 119 insertions, 0 deletions

diff --git a/benchmarks/gem_set_domain.c b/benchmarks/gem_set_domain.c
new file mode 100644
index 00000000..afb410dc
--- /dev/null
+++ b/benchmarks/gem_set_domain.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright © 2011-2015 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.
+ *
+ * Authors:
+ *    Chris Wilson <chris@chris-wilson.co.uk>
+ *
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <time.h>
+
+#include "drm.h"
+#include "ioctl_wrappers.h"
+#include "drmtest.h"
+#include "igt_aux.h"
+
+static double elapsed(const struct timespec *start,
+		      const struct timespec *end)
+{
+	return (end->tv_sec - start->tv_sec) + 1e-9*(end->tv_nsec - start->tv_nsec);
+}
+
+int main(int argc, char **argv)
+{
+	int fd = drm_open_driver(DRIVER_INTEL);
+	uint32_t cpu_write = 0;
+	uint32_t gtt_write = 0;
+	int reps = 13;
+	int size = 1024*1024;
+	uint32_t handle;
+	int c, n;
+
+	while ((c = getopt (argc, argv, "c:g:r:s:")) != -1) {
+		switch (c) {
+		case 'c':
+			cpu_write = *optarg == 'w' ? I915_GEM_DOMAIN_CPU : 0;
+			break;
+		case 'g':
+			gtt_write = *optarg == 'w' ? I915_GEM_DOMAIN_GTT : 0;
+			break;
+
+		case 'r':
+			reps = atoi(optarg);
+			if (reps < 1)
+				reps = 1;
+			break;
+
+		case 's':
+			size = atoi(optarg);
+			if (size < 4096)
+				size = 4096;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	fprintf(stderr, "size=%d, cpu=%d, gtt=%d\n", size, cpu_write, gtt_write);
+
+	handle = gem_create(fd, size);
+	gem_set_caching(fd, handle, I915_CACHING_NONE);
+
+	for (n = 0; n < reps; n++) {
+		struct timespec start, end;
+		uint64_t count = 0;
+
+		gem_set_domain(fd, handle,
+				I915_GEM_DOMAIN_CPU,
+				cpu_write);
+
+		clock_gettime(CLOCK_MONOTONIC, &start);
+		do {
+			for (c = 0; c < 1000; c++) {
+				gem_set_domain(fd, handle,
+						I915_GEM_DOMAIN_GTT,
+						gtt_write);
+				gem_set_domain(fd, handle,
+						I915_GEM_DOMAIN_CPU,
+						cpu_write);
+			}
+			count += c;
+			clock_gettime(CLOCK_MONOTONIC, &end);
+		} while (end.tv_sec - start.tv_sec < 2);
+
+		printf("%f\n", count / elapsed(&start, &end));
+	}
+
+	return 0;
+}