Draft fallback review

ggml/include/ggml.h

@@ -694,7 +694,9 @@ extern "C" {
 
         void * extra; // extra things e.g. for ggml-cuda.cu
 
-        char padding[8];
+        char padding[16];
+        // add a struct ggml_tensor * named org_src, initialized to NULL, for keeping track of original source tensors in case of in-place operations
+        struct ggml_tensor * org_src;
     };
 
     static const size_t GGML_TENSOR_SIZE = sizeof(struct ggml_tensor);

ggml/src/ggml-backend.cpp

@@ -1242,6 +1242,28 @@ void ggml_backend_sched_split_graph(ggml_backend_sched_t sched, struct ggml_cgra
         GGML_ASSERT(*cur_backend_id != -1);
     }
 
+    // OpenVINO currently uses ggml tensor names as graph indices. Some models (e.g. gpt-oss and
+    // llama4) can contain duplicate ggml tensor names, so we append node ids here to keep names
+    // unique. This is a temporary workaround and will be further optimized away in the future.
+    {
+        bool has_openvino_backend = false;
+        for (int i = 0; i < sched->n_backends; i++) {
+            if (strcmp(ggml_backend_name(sched->backends[i]), "OPENVINO") == 0) {
+                has_openvino_backend = true;
+                break;
+            }
+        }
+
+        if (has_openvino_backend) {
+            for (int i = 0; i < graph->n_nodes; i++) {
+                struct ggml_tensor * node = graph->nodes[i];
+                char                 new_name[128];
+                snprintf(new_name, sizeof(new_name), "%s#%d", node->name, i);
+                ggml_format_name(node, "%s", new_name);
+            }
+        }
+    }
+
     // pass 5: split graph, find tensors that need to be copied
     {
         int i_split = 0;
@@ -1360,6 +1382,7 @@ void ggml_backend_sched_split_graph(ggml_backend_sched_t sched, struct ggml_cgra
                                 ggml_set_input(tensor_copy);
                                 ggml_set_output(tensor_copy); // prevent ggml-alloc from overwriting the tensor
                             }
+                            tensor_copy->org_src = src;
                             tensor_id_copy(src_id, cur_backend_id, c) = tensor_copy;
                             SET_CAUSE(tensor_copy, "4.cpy");
                         }

ggml/src/ggml-openvino/CMakeLists.txt

@@ -1,8 +1,6 @@
-find_package(OpenVINO REQUIRED)
+find_package(OpenVINO REQUIRED COMPONENTS Runtime Threading)
 find_package(OpenCL REQUIRED)
 
-include("${OpenVINO_DIR}/../3rdparty/tbb/lib/cmake/TBB/TBBConfig.cmake")
-
 file(GLOB_RECURSE GGML_HEADERS_OPENVINO "*.h" "*.hpp")
 file(GLOB_RECURSE GGML_SOURCES_OPENVINO "*.cpp")
 
@@ -11,7 +9,7 @@ ggml_add_backend_library(ggml-openvino
     ${GGML_HEADERS_OPENVINO}
 )
 
-target_link_libraries(ggml-openvino PRIVATE openvino::runtime TBB::tbb OpenCL::OpenCL)
+target_link_libraries(ggml-openvino PRIVATE openvino::runtime openvino::threading OpenCL::OpenCL)
 
 if (GGML_OPENVINO)
     if (CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64")