[igt-dev] [PATCH i-g-t] i915/gem_ctx_shared: Use a spinner to keep the fence alive while querying

[Chris Wilson]

Once the fence is retired, we discard its references to the context
state, including its timeline name. So the timeline query is only
accurate before being signaled, so keep the fence alive until after the
query.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 tests/i915/gem_ctx_shared.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/tests/i915/gem_ctx_shared.c b/tests/i915/gem_ctx_shared.c
index a6eee16dd..30e37c3cc 100644
--- a/tests/i915/gem_ctx_shared.c
+++ b/tests/i915/gem_ctx_shared.c
@@ -314,25 +314,16 @@ static bool has_single_timeline(int i915)
 
 static void single_timeline(int i915)
 {
-	const uint32_t bbe = MI_BATCH_BUFFER_END;
-	struct drm_i915_gem_exec_object2 obj = {
-		.handle = gem_create(i915, 4096),
-	};
-	struct drm_i915_gem_execbuffer2 execbuf = {
-		.buffers_ptr = to_user_pointer(&obj),
-		.buffer_count = 1,
-	};
-	struct sync_fence_info rings[16];
+	struct sync_fence_info rings[64];
 	struct sync_file_info sync_file_info = {
 		.num_fences = 1,
 	};
+	igt_spin_t *spin;
 	int n;
 
 	igt_require(has_single_timeline(i915));
 
-	gem_write(i915, obj.handle, 0, &bbe, sizeof(bbe));
-	gem_execbuf(i915, &execbuf);
-	gem_sync(i915, obj.handle);
+	spin = igt_spin_new(i915);
 
 	/*
 	 * For a "single timeline" context, each ring is on the common
@@ -341,23 +332,24 @@ static void single_timeline(int i915)
 	 * to, it reports the same timeline name and fence context. However,
 	 * the fence context is not reported through the sync_fence_info.
 	 */
-	execbuf.rsvd1 =
+	spin->execbuf.rsvd1 =
 		gem_context_clone(i915, 0, 0,
 				  I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE);
-	execbuf.flags = I915_EXEC_FENCE_OUT;
 	n = 0;
 	for_each_engine(e, i915) {
-		gem_execbuf_wr(i915, &execbuf);
+		spin->execbuf.flags = eb_ring(e) | I915_EXEC_FENCE_OUT;
+
+		gem_execbuf_wr(i915, &spin->execbuf);
 		sync_file_info.sync_fence_info = to_user_pointer(&rings[n]);
-		do_ioctl(execbuf.rsvd2 >> 32, SYNC_IOC_FILE_INFO, &sync_file_info);
-		close(execbuf.rsvd2 >> 32);
+		do_ioctl(spin->execbuf.rsvd2 >> 32, SYNC_IOC_FILE_INFO, &sync_file_info);
+		close(spin->execbuf.rsvd2 >> 32);
 
 		igt_info("ring[%d] fence: %s %s\n",
 			 n, rings[n].driver_name, rings[n].obj_name);
-		n++;
+		if (++n == ARRAY_SIZE(rings))
+			break;
 	}
-	gem_sync(i915, obj.handle);
-	gem_close(i915, obj.handle);
+	igt_spin_free(i915, spin);
 
 	for (int i = 1; i < n; i++) {
 		igt_assert(!strcmp(rings[0].driver_name, rings[i].driver_name));
-- 
2.24.0