Add a GTT timing test

Using for diagnosing some mysterious slowdowns. Should include a variant
for basic benchmarking...
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

.gitignore

@@ -36,6 +36,7 @@ tests/getversion
 tests/gem_basic
 tests/gem_fence_thrash
 tests/gem_flink
+tests/gem_gtt_speed
 tests/gem_largeobject
 tests/gem_mmap
 tests/gem_pread_after_blit

tests/Makefile.am

@@ -14,7 +14,9 @@ TESTS = getversion \
 	gem_bad_blit \
 	gem_bad_batch \
 	gem_hang \
-	gem_fence_thrash
+	gem_fence_thrash \
+	gem_gtt_speed \
+	$(NULL)
 
 EXTRA_PROGRAMS = $(TESTS)
 CLEANFILES = $(EXTRA_PROGRAMS)

tests/gem_gtt_speed.c

+/*
+ * Copyright © 2010 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:
+ *    Eric Anholt <eric@anholt.net>
+ *    Chris Wilson <chris@chris-wilson.co.uk>
+ *
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include "drm.h"
+#include "i915_drm.h"
+#include "drmtest.h"
+
+#define OBJECT_SIZE 16384
+
+static uint32_t gem_create(int fd, int size)
+{
+	struct drm_i915_gem_create create;
+
+	create.handle = 0;
+	create.size = size;
+	(void)drmIoctl(fd, DRM_IOCTL_I915_GEM_CREATE, &create);
+
+	return create.handle;
+}
+
+static void *gem_mmap(int fd, uint32_t handle, int size, int prot)
+{
+	struct drm_i915_gem_mmap_gtt mmap_arg;
+	void *ptr;
+
+	mmap_arg.handle = handle;
+	if (drmIoctl(fd, DRM_IOCTL_I915_GEM_MMAP_GTT, &mmap_arg))
+		return NULL;
+
+	ptr = mmap(0, size, prot, MAP_SHARED, fd, mmap_arg.offset);
+	if (ptr == MAP_FAILED)
+		ptr = NULL;
+
+	return ptr;
+}
+
+static int gem_write(int fd,
+		     uint32_t handle, uint32_t offset,
+		     const void *src, int length)
+{
+	struct drm_i915_gem_pwrite pwrite;
+
+	pwrite.handle = handle;
+	pwrite.offset = offset;
+	pwrite.size = length;
+	pwrite.data_ptr = (uintptr_t)src;
+	return drmIoctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite);
+}
+
+static int gem_read(int fd,
+		    uint32_t handle, uint32_t offset,
+		    const void *src, int length)
+{
+	struct drm_i915_gem_pread pread;
+
+	pread.handle = handle;
+	pread.offset = offset;
+	pread.size = length;
+	pread.data_ptr = (uintptr_t)src;
+	return drmIoctl(fd, DRM_IOCTL_I915_GEM_PREAD, &pread);
+}
+
+static void gem_set_tiling(int fd, uint32_t handle, int tiling)
+{
+	struct drm_i915_gem_set_tiling set_tiling;
+	int ret;
+
+	do {
+		set_tiling.handle = handle;
+		set_tiling.tiling_mode = tiling;
+		set_tiling.stride = 512;
+
+		ret = ioctl(fd, DRM_IOCTL_I915_GEM_SET_TILING, &set_tiling);
+	} while (ret == -1 && (errno == EINTR || errno == EAGAIN));
+}
+
+static void gem_close(int fd, uint32_t handle)
+{
+	struct drm_gem_close close;
+
+	close.handle = handle;
+	(void)drmIoctl(fd, DRM_IOCTL_GEM_CLOSE, &close);
+}
+
+static double elapsed(const struct timeval *start,
+		      const struct timeval *end,
+		      int loop)
+{
+	return (1e6*(end->tv_sec - start->tv_sec) + (end->tv_usec - start->tv_usec))/loop;
+}
+
+int main(int argc, char **argv)
+{
+	struct timeval start, end;
+	uint8_t buf[OBJECT_SIZE];
+	uint32_t handle;
+	int loop, i, tiling;
+	int fd;
+
+	fd = drm_open_any();
+
+	handle = gem_create(fd, OBJECT_SIZE);
+	assert(handle);
+
+	for (tiling = I915_TILING_NONE; tiling <= I915_TILING_Y; tiling++) {
+		if (tiling != I915_TILING_NONE) {
+			printf("\nSetting tiling mode to %s\n",
+			       tiling == I915_TILING_X ? "X" : "Y");
+			gem_set_tiling(fd, handle, tiling);
+		}
+
+		if (tiling == I915_TILING_NONE) {
+			/* CPU pwrite */
+			gettimeofday(&start, NULL);
+			for (loop = 0; loop < 1000; loop++)
+				gem_write(fd, handle, 0, buf, sizeof(buf));
+			gettimeofday(&end, NULL);
+			printf("Time to pwrite 16k through the CPU:		%7.3fµs\n",
+			       elapsed(&start, &end, loop));
+
+			/* CPU pread */
+			gettimeofday(&start, NULL);
+			for (loop = 0; loop < 1000; loop++)
+				gem_read(fd, handle, 0, buf, sizeof(buf));
+			gettimeofday(&end, NULL);
+			printf("Time to pread 16k through the CPU:		%7.3fµs\n",
+			       elapsed(&start, &end, loop));
+		}
+
+		/* mmap read */
+		gettimeofday(&start, NULL);
+		for (loop = 0; loop < 1000; loop++) {
+			volatile uint32_t *ptr = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ);
+			int x = 0;
+
+			for (i = 0; i < OBJECT_SIZE/sizeof(*ptr); i++)
+				x += ptr[i];
+
+			munmap((void *)ptr, OBJECT_SIZE);
+		}
+		gettimeofday(&end, NULL);
+		printf("Time to read 16k through a GTT map:		%7.3fµs\n",
+		       elapsed(&start, &end, loop));
+
+		/* mmap write */
+		gettimeofday(&start, NULL);
+		for (loop = 0; loop < 1000; loop++) {
+			volatile uint32_t *ptr = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+
+			for (i = 0; i < OBJECT_SIZE/sizeof(*ptr); i++)
+				ptr[i] = i;
+
+			munmap((void *)ptr, OBJECT_SIZE);
+		}
+		gettimeofday(&end, NULL);
+		printf("Time to write 16k through a GTT map:		%7.3fµs\n",
+		       elapsed(&start, &end, loop));
+
+		/* mmap read */
+		gettimeofday(&start, NULL);
+		for (loop = 0; loop < 1000; loop++) {
+			volatile uint32_t *ptr = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ);
+			int x = 0;
+
+			for (i = 0; i < OBJECT_SIZE/sizeof(*ptr); i++)
+				x += ptr[i];
+
+			munmap((void *)ptr, OBJECT_SIZE);
+		}
+		gettimeofday(&end, NULL);
+		printf("Time to read 16k (again) through a GTT map:	%7.3fµs\n",
+		       elapsed(&start, &end, loop));
+
+		if (tiling == I915_TILING_NONE) {
+			/* GTT pwrite */
+			gettimeofday(&start, NULL);
+			for (loop = 0; loop < 1000; loop++)
+				gem_write(fd, handle, 0, buf, sizeof(buf));
+			gettimeofday(&end, NULL);
+			printf("Time to pwrite 16k through the GTT:		%7.3fµs\n",
+			       elapsed(&start, &end, loop));
+
+			/* GTT pread */
+			gettimeofday(&start, NULL);
+			for (loop = 0; loop < 1000; loop++)
+				gem_read(fd, handle, 0, buf, sizeof(buf));
+			gettimeofday(&end, NULL);
+			printf("Time to pread 16k through the GTT:		%7.3fµs\n",
+			       elapsed(&start, &end, loop));
+		}
+
+	}
+
+	gem_close(fd, handle);
+	close(fd);
+
+	return 0;
+}