gem_pread: Symmetric measurement to gem_pwrite

tests/Makefile.am

@@ -71,6 +71,7 @@ TESTS_progs = \
 	gem_mmap_offset_exhaustion \
 	gem_pin \
 	gem_pipe_control_store_loop \
+	gem_pread \
 	gem_pwrite \
 	gem_readwrite \
 	gem_reg_read \

tests/gem_pread.c

@@ -0,0 +1,134 @@
+/*
+ * 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.
+ *
+ * Authors:
+ *    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 void do_gem_read(int fd, uint32_t handle, void *buf, int len, int loops)
+{
+	while (loops--)
+		gem_read(fd, handle, 0, buf, len);
+}
+
+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;
+}
+
+static const char *bytes_per_sec(char *buf, double v)
+{
+	const char *order[] = {
+		"",
+		"KiB",
+		"MiB",
+		"GiB",
+		"TiB",
+		NULL,
+	}, **o = order;
+
+	while (v > 1000 && o[1]) {
+		v /= 1000;
+		o++;
+	}
+	sprintf(buf, "%.1f%s/s", v, *o);
+	return buf;
+}
+
+
+int main(int argc, char **argv)
+{
+	int object_size = 0;
+	uint32_t buf[20];
+	uint32_t *src, dst;
+	int fd, count;
+
+	drmtest_skip_on_simulation();
+
+	if (argc > 1)
+		object_size = atoi(argv[1]);
+	if (object_size == 0)
+		object_size = OBJECT_SIZE;
+	object_size = (object_size + 3) & -4;
+
+	fd = drm_open_any();
+
+	dst = gem_create(fd, object_size);
+	src = malloc(object_size);
+
+	gem_set_cacheing(fd, dst, 0);
+	for (count = 1; count <= 1<<17; count <<= 1) {
+		struct timeval start, end;
+
+		gettimeofday(&start, NULL);
+		do_gem_read(fd, dst, src, object_size, count);
+		gettimeofday(&end, NULL);
+		printf("Time to uncached pread %d bytes x %6d:	%7.3fµs, %s\n",
+		       object_size, count,
+		       elapsed(&start, &end, count),
+		       bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
+		fflush(stdout);
+	}
+
+	gem_set_cacheing(fd, dst, 1);
+	for (count = 1; count <= 1<<17; count <<= 1) {
+		struct timeval start, end;
+
+		gettimeofday(&start, NULL);
+		do_gem_read(fd, dst, src, object_size, count);
+		gettimeofday(&end, NULL);
+		printf("Time to snooped pread %d bytes x %6d:	%7.3fµs, %s\n",
+		       object_size, count,
+		       elapsed(&start, &end, count),
+		       bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
+		fflush(stdout);
+	}
+
+	free(src);
+	gem_close(fd, dst);
+
+	close(fd);
+
+	return 0;
+}