i915/gem_exec_alignment: Cap object setup time

Instantiating the objects can be surprisingly, worryingly slow; even on
big core LLC devices. Rather than worry about that and cause timeouts in
simply setting up the test, apply a limit to the setup time so that we
only use the amount of objects instantiated within the first 20s.

Due to the quadratic behaviour being exposed by the test, this may not
entirely eliminate the timeouts -- but at least the timeouts should then
be for the right reason.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

1 files changed, 37 insertions, 23 deletions

diff --git a/tests/i915/gem_exec_alignment.c b/tests/i915/gem_exec_alignment.c
index 2139b7cc..1c06b18a 100644
--- a/tests/i915/gem_exec_alignment.c
+++ b/tests/i915/gem_exec_alignment.c
@@ -123,6 +123,19 @@ static uint32_t batch_create(int i915, unsigned long sz)
 	return handle;
 }
 
+static unsigned long create_batch(int i915,
+				  struct drm_i915_gem_exec_object2 *obj,
+				  unsigned long from, unsigned long to,
+				  unsigned int flags)
+{
+	for (unsigned long i = from; i < to; i++) {
+		obj[i].handle = batch_create(i915, 4096);
+		obj[i].flags = flags;
+	}
+
+	return to;
+}
+
 static void sighandler(int sig)
 {
 }
@@ -159,27 +172,41 @@ naughty_child(int i915, int link, uint32_t shared, unsigned int flags)
 		count = file_max();
 	intel_require_memory(count, 4096, CHECK_RAM);
 
+	flags = 0;
+	if ((gtt_size - 1) >> 32)
+		flags |= EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
+
 	/* Fill the low-priority address space */
 	obj = calloc(sizeof(*obj), count);
 	igt_assert(obj);
-	for (unsigned long i = 0; i < count; i++) {
-		obj[i].handle = batch_create(i915, 4096);
-		if ((gtt_size - 1) >> 32)
-			obj[i].flags |= EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
-		obj[i].alignment = 4096;
+
+	memset(&execbuf, 0, sizeof(execbuf));
+	execbuf.buffers_ptr = to_user_pointer(obj);
+	execbuf.buffer_count = create_batch(i915, obj, 0, 1, flags);
+	execbuf.rsvd1 = gem_context_create(i915);
+	gem_execbuf(i915, &execbuf);
+
+	igt_seconds_elapsed(memset(&tv, 0, sizeof(tv)));
+	for (unsigned long i = 1; i < count; i *= 2) {
+		execbuf.buffer_count =
+			create_batch(i915, obj, execbuf.buffer_count, i, flags);
+		gem_execbuf(i915, &execbuf);
+		if (igt_seconds_elapsed(&tv) > 8) {
+			count = i;
+			break;
+		}
 	}
 	if (shared) {
 		gem_close(i915, obj[0].handle);
 		obj[0].handle = shared;
 	}
-
-	memset(&execbuf, 0, sizeof(execbuf));
-	execbuf.buffers_ptr = to_user_pointer(obj);
-	execbuf.buffer_count = count;
-	execbuf.rsvd1 = gem_context_create(i915);
+	execbuf.buffer_count =
+		create_batch(i915, obj, execbuf.buffer_count, count, flags);
 	gem_execbuf(i915, &execbuf);
+	igt_debug("Created %lu buffers ready for delay\n", count);
 
 	/* Calibrate a long execbuf() */
+	memset(&tv, 0, sizeof(tv));
 	for (unsigned long i = 0; i < count; i++)
 		obj[i].alignment = 8192;
 
@@ -316,19 +343,6 @@ static void __many(int fd, int timeout,
 	reset_timeout();
 }
 
-static unsigned long create_batch(int i915,
-				  struct drm_i915_gem_exec_object2 *obj,
-				  unsigned long from, unsigned long to,
-				  unsigned int flags)
-{
-	for (unsigned long i = from; i < to; i++) {
-		obj[i].handle = batch_create(i915, 4096);
-		obj[i].flags = flags;
-	}
-
-	return to;
-}
-
 static struct drm_i915_gem_exec_object2 *
 setup_many(int i915, unsigned long *out)
 {