benchmarks: Add gem_exec_fault

If we specify an unobtainable alignment (e.g, 63bits) the kernel will
eviction the object from the GTT and fail to rebind it. We can use this,
to measure how long it takes to move objects around in the GTT by
running execbuf followed by the unbind. For small objects, this will be
dominated by the nop execution time, but for larger objects this will be
ratelimited by how fast we can rewrite the PTE.

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

1 files changed, 198 insertions, 0 deletions

diff --git a/benchmarks/gem_exec_fault.c b/benchmarks/gem_exec_fault.c
new file mode 100644
index 00000000..d23db3ba
--- /dev/null
+++ b/benchmarks/gem_exec_fault.c
@@ -0,0 +1,198 @@
+/*
+ * 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>
+ *
+ */
+
+/* Measure the time it to takes to bind/unbind objects from the ppGTT */
+
+#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"
+
+#define LOCAL_I915_EXEC_NO_RELOC (1<<11)
+#define LOCAL_I915_EXEC_HANDLE_LUT (1<<12)
+
+#define LOCAL_I915_EXEC_BSD_SHIFT      (13)
+#define LOCAL_I915_EXEC_BSD_MASK       (3 << LOCAL_I915_EXEC_BSD_SHIFT)
+
+#define ENGINE_FLAGS  (I915_EXEC_RING_MASK | LOCAL_I915_EXEC_BSD_MASK)
+
+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);
+}
+
+static uint32_t batch(int fd, int size)
+{
+	const uint32_t buf[] = {MI_BATCH_BUFFER_END};
+	uint32_t handle = gem_create(fd, size);
+	gem_write(fd, handle, 0, buf, sizeof(buf));
+	return handle;
+}
+
+static int loop(int size, unsigned ring, int reps, int ncpus, unsigned flags)
+{
+	struct drm_i915_gem_execbuffer2 execbuf;
+	struct drm_i915_gem_exec_object2 obj;
+	unsigned engines[16];
+	unsigned nengine;
+	double *shared;
+	int fd;
+
+	shared = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+
+	fd = drm_open_driver(DRIVER_INTEL);
+
+	memset(&obj, 0, sizeof(obj));
+	obj.handle = batch(fd, size);
+
+	memset(&execbuf, 0, sizeof(execbuf));
+	execbuf.buffers_ptr = (uintptr_t)&obj;
+	execbuf.buffer_count = 1;
+	execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
+	execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
+	if (__gem_execbuf(fd, &execbuf)) {
+		execbuf.flags = 0;
+		if (__gem_execbuf(fd, &execbuf))
+			return 77;
+	}
+	gem_close(fd, obj.handle);
+
+	nengine = 0;
+	if (ring == -1) {
+		for (ring = 1; ring < 16; ring++) {
+			execbuf.flags &= ~ENGINE_FLAGS;
+			execbuf.flags |= ring;
+			if (__gem_execbuf(fd, &execbuf) == 0)
+				engines[nengine++] = ring;
+		}
+	} else
+		engines[nengine++] = ring;
+
+	while (reps--) {
+		memset(shared, 0, 4096);
+
+		igt_fork(child, ncpus) {
+			struct timespec start, end;
+			unsigned count = 0;
+
+			obj.handle = batch(fd, size);
+
+			clock_gettime(CLOCK_MONOTONIC, &start);
+			do {
+				for (int inner = 0; inner < 1024; inner++) {
+					execbuf.flags &= ~ENGINE_FLAGS;
+					execbuf.flags |= engines[count++ % nengine];
+					/* fault in */
+					gem_execbuf(fd, &execbuf);
+
+					/* fault out */
+					obj.alignment = 1ull << 63;
+					__gem_execbuf(fd, &execbuf);
+				}
+
+				clock_gettime(CLOCK_MONOTONIC, &end);
+			} while (elapsed(&start, &end) < 2.);
+
+			gem_sync(fd, obj.handle);
+			clock_gettime(CLOCK_MONOTONIC, &end);
+			shared[child] = 1e6*elapsed(&start, &end) / count / 2;
+
+			gem_close(fd, obj.handle);
+		}
+		igt_waitchildren();
+
+		for (int child = 0; child < ncpus; child++)
+			shared[ncpus] += shared[child];
+		printf("%7.3f\n", shared[ncpus] / ncpus);
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned ring = I915_EXEC_RENDER;
+	unsigned flags = 0;
+	int size = 4096;
+	int reps = 1;
+	int ncpus = 1;
+	int c;
+
+	while ((c = getopt (argc, argv, "e:r:s:f")) != -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 if (strcmp(optarg, "all") == 0)
+				ring = -1;
+			else
+				ring = atoi(optarg);
+			break;
+
+		case 'r':
+			reps = atoi(optarg);
+			if (reps < 1)
+				reps = 1;
+			break;
+
+		case 'f':
+			ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+			break;
+
+		case 's':
+			size = atoi(optarg);
+			if (size < 4096)
+				size = 4096;
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	return loop(size, ring, reps, ncpus, flags);
+}