CUDA: make cuda graphs props check faster (#21472)

* CUDA: compute fast hash instead of expensive props check

* use seen node

* use memcp

Author: am17an

ggml/src/ggml-cuda/common.cuh

@@ -1157,19 +1157,6 @@ struct ggml_tensor_extra_gpu {
 #define USE_CUDA_GRAPH
 #endif
 
-struct ggml_cuda_graph_node_properties {
-    void * node_data;
-    ggml_op node_op;
-    enum ggml_type node_type;
-    int32_t flags;
-    int64_t ne[GGML_MAX_DIMS];
-    size_t nb[GGML_MAX_DIMS];
-    void * src_data[GGML_MAX_SRC];
-    int32_t op_params[GGML_MAX_OP_PARAMS / sizeof(int32_t)];
-};
-
-static_assert(std::is_trivial<ggml_cuda_graph_node_properties>::value, "ggml_cuda_graph_node_properties must be trivial");
-
 struct ggml_cuda_graph {
 #ifdef USE_CUDA_GRAPH
     ~ggml_cuda_graph() {
@@ -1186,13 +1173,7 @@ struct ggml_cuda_graph {
     std::vector<cudaGraphNode_t> nodes;
     bool disable_due_to_gpu_arch = false;
     bool warmup_complete = false;
-    std::vector<ggml_cuda_graph_node_properties> props;
-
-    // these are extra tensors (inputs) that participate in the ggml graph but are not nodes
-    // they properties also have to match in order to be able to safely reuse a CUDA graph
-    // ref: https://github.com/ggml-org/llama.cpp/pull/18583
-    // ref: https://github.com/ggml-org/llama.cpp/pull/19165
-    std::vector<ggml_cuda_graph_node_properties> extra;
+    std::vector<ggml_tensor> nodes_copy;
 
     bool is_enabled() const {
         static const bool disable_cuda_graphs_due_to_env = (getenv("GGML_CUDA_DISABLE_GRAPHS") != nullptr);

ggml/src/ggml-cuda/ggml-cuda.cu

@@ -82,7 +82,6 @@
 #include <cstdlib>
 #include <string>
 #include <vector>
-#include <unordered_set>
 
 static_assert(sizeof(half) == sizeof(ggml_fp16_t), "wrong fp16 size");
 
@@ -2969,74 +2968,6 @@ static bool ggml_cuda_graph_check_compability(ggml_cgraph * cgraph) {
     return use_cuda_graph;
 }
 
-static void ggml_cuda_graph_node_set_properties(ggml_cuda_graph_node_properties * props, ggml_tensor * node) {
-    memset(props, 0, sizeof(ggml_cuda_graph_node_properties));
-    props->node_data = node->data;
-    props->node_op = node->op;
-    props->node_type = node->type;
-    props->flags = node->flags;
-    for (int i = 0; i < GGML_MAX_DIMS; i++) {
-        props->ne[i] = node->ne[i];
-        props->nb[i] = node->nb[i];
-    }
-    for (int i = 0; i < GGML_MAX_SRC; i++) {
-        if (!node->src[i]) {
-            continue;
-        }
-
-        props->src_data[i] = node->src[i]->data;
-    }
-    memcpy(props->op_params, node->op_params, GGML_MAX_OP_PARAMS);
-}
-
-static bool ggml_cuda_graph_node_properties_match(ggml_tensor * node, ggml_cuda_graph_node_properties * props) {
-    if (node->data != props->node_data && node->op != GGML_OP_VIEW) {
-        return false;
-    }
-
-    if (node->op != props->node_op) {
-        return false;
-    }
-
-    if (node->type != props->node_type) {
-        return false;
-    }
-
-    for (int i = 0; i < GGML_MAX_DIMS; i++) {
-        if (node->ne[i] != props->ne[i]) {
-            return false;
-        }
-        if (node->nb[i] != props->nb[i]) {
-            return false;
-        }
-    }
-
-    if (node->op != GGML_OP_VIEW) {
-        for (int i = 0; i < GGML_MAX_SRC; i++) {
-            if (!node->src[i]) {
-                if (props->src_data[i] != nullptr) {
-                    return false;
-                }
-                continue;
-            }
-
-            if (node->src[i]->data != props->src_data[i]) {
-                return false;
-            }
-        }
-    }
-
-    if (memcmp(props->op_params, node->op_params, GGML_MAX_OP_PARAMS) != 0) {
-        return false;
-    }
-
-    if ((node->flags & GGML_TENSOR_FLAG_COMPUTE) != (props->flags & GGML_TENSOR_FLAG_COMPUTE)) {
-        return false;
-    }
-
-    return true;
-}
-
 static const void * ggml_cuda_graph_get_key(ggml_cgraph * cgraph) {
     return cgraph->nodes[0];
 }
@@ -3048,52 +2979,18 @@ static bool ggml_cuda_graph_update_required(ggml_backend_cuda_context * cuda_ctx
     ggml_cuda_graph * graph = cuda_ctx->cuda_graph(graph_key);
 
     // Check if the graph size has changed
-    if (graph->props.size() != (size_t)cgraph->n_nodes) {
+    if ((int)graph->nodes_copy.size() != cgraph->n_nodes) {
         res = true;
-        graph->props.resize(cgraph->n_nodes);
+        graph->nodes_copy.resize(cgraph->n_nodes);
     }
 
-    // Loop over nodes in GGML graph to determine if CUDA graph update is required
-    // and store properties to allow this comparison for the next token
-    std::unordered_set<ggml_tensor *> seen_node;
-    std::vector<ggml_tensor *> srcs_extra;
     for (int i = 0; i < cgraph->n_nodes; i++) {
-        bool props_match = true;
-
-        seen_node.insert(cgraph->nodes[i]);
-
         if (!res) {
-            props_match = ggml_cuda_graph_node_properties_match(cgraph->nodes[i], &graph->props[i]);
-        }
-        if (!props_match) {
-            res = true;
-        }
-        ggml_cuda_graph_node_set_properties(&graph->props[i], cgraph->nodes[i]);
-
-        for (int src_idx = 0; src_idx < GGML_MAX_SRC; ++src_idx) {
-            ggml_tensor * src = cgraph->nodes[i]->src[src_idx];
-            if (src && seen_node.find(src) == seen_node.end()) {
-                srcs_extra.push_back(src);
+            if (memcmp(&graph->nodes_copy[i], cgraph->nodes[i], sizeof(ggml_tensor)) != 0) {
+                res = true;
             }
         }
-    }
-
-    if (graph->extra.size() != (size_t) srcs_extra.size()) {
-        res = true;
-        graph->extra.resize(srcs_extra.size());
-    }
-
-    for (size_t i = 0; i < srcs_extra.size(); ++i) {
-        bool props_match = true;
-
-        if (!res) {
-            props_match = ggml_cuda_graph_node_properties_match(srcs_extra[i], &graph->extra[i]);
-        }
-
-        if (!props_match) {
-            res = true;
-        }
-        ggml_cuda_graph_node_set_properties(&graph->extra[i], srcs_extra[i]);
+        memcpy(&graph->nodes_copy[i], cgraph->nodes[i], sizeof(ggml_tensor));
     }
 
     return res;