diff --git a/tests/Makefile.sources b/tests/Makefile.sources
index 15d8382..7c2eec7 100644
--- a/tests/Makefile.sources
+++ b/tests/Makefile.sources
@@ -53,6 +53,7 @@ TESTS_progs_M = \
 	gem_render_copy_redux \
 	gem_reset_stats \
 	gem_ringfill \
+	gem_ringfill_noop \
 	gem_set_tiling_vs_blt \
 	gem_storedw_batches_loop \
 	gem_streaming_writes \
diff --git a/tests/gem_ringfill.c b/tests/gem_ringfill.c
index 85b01ea..ac823ba 100644
--- a/tests/gem_ringfill.c
+++ b/tests/gem_ringfill.c
@@ -54,6 +54,8 @@ struct bo {
 	drm_intel_bo *src, *dst, *tmp;
 };
 
+static bool opt_noop = false;
+
 static const int width = 512, height = 512;
 
 static void create_bo(drm_intel_bufmgr *bufmgr,
@@ -75,11 +77,11 @@ static void create_bo(drm_intel_bufmgr *bufmgr,
 		map[i] = i;
 	drm_intel_bo_unmap(b->src);
 
-	/* Fill the dst with garbage. */
+	/* Fill the dst with another pattern. */
 	drm_intel_bo_map(b->dst, true);
 	map = b->dst->virtual;
 	for (i = 0; i < width * height; i++)
-		map[i] = 0xd0d0d0d0;
+		map[i] = opt_noop ? 0xd0d0d0d0 ^ i : 0xd0d0d0d0;
 	drm_intel_bo_unmap(b->dst);
 }
 
@@ -91,12 +93,13 @@ static int check_bo(struct bo *b)
 	drm_intel_bo_map(b->dst, false);
 	map = b->dst->virtual;
 	for (i = 0; i < width*height; i++) {
-		if (map[i] != i && ++fails <= 9) {
+		uint32_t pattern = opt_noop ? 0xd0d0d0d0 ^ i : i;
+		if (map[i] != pattern && ++fails <= 9) {
 			int x = i % width;
 			int y = i / width;
 
-			igt_info("%s: copy #%d at %d,%d failed: read 0x%08x\n",
-				 b->ring, i, x, y, map[i]);
+			igt_info("%s: copy #%d at %d,%d failed: read 0x%08x (expected 0x%08x)\n",
+				 b->ring, i, x, y, map[i], pattern);
 		}
 	}
 	drm_intel_bo_unmap(b->dst);
@@ -193,6 +196,38 @@ static void blt_copy(struct intel_batchbuffer *batch,
 	intel_batchbuffer_flush(batch);
 }
 
+static void fill_noop(struct intel_batchbuffer *batch)
+{
+	/* Fill batch with NOOP. */
+	int nr_noop = (BATCH_SZ - BATCH_RESERVED)/4;
+	int i;
+
+	BEGIN_BATCH(nr_noop, 0);
+	for (i = 0; i < nr_noop; ++i)
+		OUT_BATCH(MI_NOOP);
+	ADVANCE_BATCH();
+}
+
+static void blt_noop(struct intel_batchbuffer *batch,
+		     drm_intel_context *context,
+		     struct igt_buf *src, unsigned src_x, unsigned src_y,
+		     unsigned w, unsigned h,
+		     struct igt_buf *dst, unsigned dst_x, unsigned dst_y)
+{
+	fill_noop(batch);
+	intel_batchbuffer_flush_on_ring(batch, I915_EXEC_RENDER);
+}
+
+static void render_noop(struct intel_batchbuffer *batch,
+			drm_intel_context *context,
+			struct igt_buf *src, unsigned src_x, unsigned src_y,
+			unsigned w, unsigned h,
+			struct igt_buf *dst, unsigned dst_x, unsigned dst_y)
+{
+	fill_noop(batch);
+	intel_batchbuffer_flush_on_ring(batch, I915_EXEC_BLT);
+}
+
 drm_intel_bufmgr *bufmgr;
 struct intel_batchbuffer *batch;
 int fd;
@@ -201,6 +236,9 @@ igt_main
 {
 	igt_skip_on_simulation();
 
+	if (strstr(igt_test_name(), "noop"))
+		opt_noop = true;
+
 	igt_fixture {
 		fd = drm_open_any();
 
@@ -210,7 +248,7 @@ igt_main
 	}
 
 	igt_subtest("blitter")
-		check_ring(bufmgr, batch, "blt", blt_copy);
+		check_ring(bufmgr, batch, "blt", opt_noop ? blt_noop : blt_copy);
 
 	/* Strictly only required on architectures with a separate BLT ring,
 	 * but lets stress everybody.
@@ -221,12 +259,12 @@ igt_main
 		copy = igt_get_render_copyfunc(batch->devid);
 		igt_require(copy);
 
-		check_ring(bufmgr, batch, "render", copy);
+		check_ring(bufmgr, batch, "render", opt_noop ? render_noop : copy);
 	}
 
 	igt_fork_signal_helper();
 	igt_subtest("blitter-interruptible")
-		check_ring(bufmgr, batch, "blt", blt_copy);
+		check_ring(bufmgr, batch, "blt", opt_noop ? blt_noop : blt_copy);
 
 	/* Strictly only required on architectures with a separate BLT ring,
 	 * but lets stress everybody.
@@ -237,10 +275,32 @@ igt_main
 		copy = igt_get_render_copyfunc(batch->devid);
 		igt_require(copy);
 
-		check_ring(bufmgr, batch, "render", copy);
+		check_ring(bufmgr, batch, "render", opt_noop ? render_noop : copy);
 	}
 	igt_stop_signal_helper();
 
+	igt_subtest("blitter-forked") {
+		igt_fork(child, 1) {
+			check_ring(bufmgr, batch, "blt", opt_noop ? blt_noop : blt_copy);
+		}
+		igt_waitchildren();
+	}
+
+	/* Strictly only required on architectures with a separate BLT ring,
+	 * but lets stress everybody.
+	 */
+	igt_subtest("render-forked") {
+		igt_render_copyfunc_t copy;
+
+		copy = igt_get_render_copyfunc(batch->devid);
+		igt_require(copy);
+
+		igt_fork(child, 1) {
+			check_ring(bufmgr, batch, "render", opt_noop ? render_noop : copy);
+		}
+		igt_waitchildren();
+	}
+
 	igt_fixture {
 		intel_batchbuffer_free(batch);
 		drm_intel_bufmgr_destroy(bufmgr);
diff --git a/tests/gem_ringfill_noop.c b/tests/gem_ringfill_noop.c
new file mode 100644
index 0000000..1a4356a
--- /dev/null
+++ b/tests/gem_ringfill_noop.c
@@ -0,0 +1,2 @@
+/* See gem_concurrent_blit.c for explanation. */
+#include "gem_ringfill.c"
