benchmarks: Benchmarkify gem_exec_ctx

Measure the overhead of execution when doing nothing, switching between
a pair of contexts, or creating a new context every time.

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

benchmarks/.gitignore

@@ -1,3 +1,4 @@
+gem_exec_ctx
 gem_exec_nop
 gem_mmap
 gem_prw

benchmarks/Makefile.sources

@@ -3,6 +3,7 @@ bin_PROGRAMS =                          \
 	intel_upload_blit_large_gtt     \
 	intel_upload_blit_large_map     \
 	intel_upload_blit_small		\
+	gem_exec_ctx			\
 	gem_exec_nop			\
 	gem_mmap			\
 	gem_prw				\

benchmarks/gem_exec_ctx.c

@@ -0,0 +1,202 @@
+/*
+ * 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 <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 "intel_io.h"
+#include "igt_stats.h"
+
+enum mode { NOP, CREATE, SWITCH, };
+
+#define LOCAL_I915_EXEC_NO_RELOC (1<<11)
+#define LOCAL_I915_EXEC_HANDLE_LUT (1<<12)
+
+static uint64_t elapsed(const struct timespec *start,
+		const struct timespec *end,
+		int loop)
+{
+	return (1000000000ULL*(end->tv_sec - start->tv_sec) + (end->tv_nsec - start->tv_nsec))/loop;
+}
+
+static int __gem_execbuf(int fd, struct drm_i915_gem_execbuffer2 *execbuf)
+{
+	int err = 0;
+	if (drmIoctl(fd, DRM_IOCTL_I915_GEM_EXECBUFFER2, execbuf))
+		err = -errno;
+	return err;
+}
+
+static uint32_t batch(int fd)
+{
+	const uint32_t buf[] = {MI_BATCH_BUFFER_END};
+	uint32_t handle = gem_create(fd, 4096);
+	gem_write(fd, handle, 0, buf, sizeof(buf));
+	return handle;
+}
+
+static uint32_t __gem_context_create(int fd)
+{
+	struct drm_i915_gem_context_create create;
+
+	memset(&create, 0, sizeof(create));
+	drmIoctl(fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &create);
+
+	return create.ctx_id;
+}
+
+static int loop(unsigned ring, int reps, enum mode mode)
+{
+	struct drm_i915_gem_execbuffer2 execbuf;
+	struct drm_i915_gem_exec_object2 gem_exec;
+	int count, fd;
+	uint32_t ctx;
+
+	fd = drm_open_any();
+
+	memset(&gem_exec, 0, sizeof(gem_exec));
+	gem_exec.handle = batch(fd);
+
+	memset(&execbuf, 0, sizeof(execbuf));
+	execbuf.buffers_ptr = (uintptr_t)&gem_exec;
+	execbuf.buffer_count = 1;
+	execbuf.flags = ring;
+	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
+	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
+	execbuf.rsvd1 = __gem_context_create(fd);
+	if (execbuf.rsvd1 == 0)
+		return 77;
+
+	if (__gem_execbuf(fd, &execbuf)) {
+		execbuf.flags = ring;
+		if (__gem_execbuf(fd, &execbuf))
+			return 77;
+	}
+
+	ctx = gem_context_create(fd);
+
+	for (count = 1; count <= 1<<16; count <<= 1) {
+		igt_stats_t stats;
+		int n;
+
+		igt_stats_init_with_size(&stats, reps);
+
+		for (n = 0; n < reps; n++) {
+			struct timespec start, end;
+			int loops = count;
+			sleep(1); /* wait for the hw to go back to sleep */
+			clock_gettime(CLOCK_MONOTONIC, &start);
+			while (loops--) {
+				uint32_t tmp;
+				switch (mode) {
+				case CREATE:
+					ctx = execbuf.rsvd1;
+					execbuf.rsvd1 = gem_context_create(fd);
+					break;
+
+				case SWITCH:
+					tmp = execbuf.rsvd1;
+					execbuf.rsvd1 = ctx;
+					ctx = tmp;
+					break;
+				case NOP:
+					break;
+				}
+				do_ioctl(fd, DRM_IOCTL_I915_GEM_EXECBUFFER2, &execbuf);
+				if (mode == CREATE)
+					gem_context_destroy(fd, ctx);
+			}
+			gem_sync(fd, gem_exec.handle);
+			clock_gettime(CLOCK_MONOTONIC, &end);
+			igt_stats_push(&stats, elapsed(&start, &end, count));
+		}
+
+		printf("%7.3f\n", igt_stats_get_trimean(&stats)/1000);
+		igt_stats_fini(&stats);
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned ring = I915_EXEC_RENDER;
+	enum mode mode = NOP;
+	int reps = 13;
+	int c;
+
+	while ((c = getopt (argc, argv, "e:r:b:")) != -1) {
+		switch (c) {
+		case 'e':
+			if (strcmp(optarg, "rcs") == 0)
+				ring = I915_EXEC_RENDER;
+			else if (strcmp(optarg, "vcs") == 0)
+				ring = I915_EXEC_BSD;
+			else if (strcmp(optarg, "bcs") == 0)
+				ring = I915_EXEC_BLT;
+			else if (strcmp(optarg, "vecs") == 0)
+				ring = I915_EXEC_VEBOX;
+			else
+				ring = atoi(optarg);
+			break;
+
+		case 'b':
+			if (strcmp(optarg, "create") == 0)
+				mode = CREATE;
+			else if (strcmp(optarg, "switch") == 0)
+				mode = SWITCH;
+			else if (strcmp(optarg, "nop") == 0)
+				mode = NOP;
+			else
+				abort();
+			break;
+
+		case 'r':
+			reps = atoi(optarg);
+			if (reps < 1)
+				reps = 1;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return loop(ring, reps, mode);
+}