Increase performance for Gemma3n models on NVGPUs by enabling CUDA Graph execution (#11525)

* Enable CUDA Graphs for gemma3n.

Similar to
https://github.com/ggml-org/llama.cpp/pull/14741,
though ollama has a slightly different model graph
than llama.cpp which requires different workaround
checks.

* Remove residual check by reshaping differently in gemma3n model

This should make the heuristics more robust
This commit is contained in:
Oliver Simons
2025-07-29 21:37:06 +02:00
committed by GitHub
parent c116a7523d
commit ea85e27bbd
5 changed files with 67 additions and 10 deletions

View File

@@ -2474,6 +2474,9 @@ static bool check_node_graph_compatibility_and_refresh_copy_ops(ggml_backend_cud
// Loop over nodes in GGML graph to obtain info needed for CUDA graph
cuda_ctx->cuda_graph->cpy_dest_ptrs.clear();
const std::string gemma3n_per_layer_proj_src1_name = " (reshaped)";
const std::string gemma3n_node_name = "node_";
for (int i = 0; i < cgraph->n_nodes; i++) {
ggml_tensor * node = cgraph->nodes[i];
@@ -2495,12 +2498,17 @@ static bool check_node_graph_compatibility_and_refresh_copy_ops(ggml_backend_cud
#endif
}
if (node->op == GGML_OP_ADD && node->src[1] && node->src[1]->ne[1] > 1) {
// disable CUDA graphs for batch size > 1 for now.
// Changes in batch size or context size can cause changes to the grid size of some kernels.
// workarounds to exclude Gemma3n's `project_per_layer_input` operation from the batch-size heuristic, specific to ollama's implementation of gemma3n
// number of layers is different for per_layer_proj between gemma3n:2b and gemma3n:4b, which is why we don't check that value here
if (node->op == GGML_OP_ADD && node->src[1] && node->src[1]->ne[1] > 1 && !(node->ne[0] == 256
&& node->ne[2] == 1
&& node->ne[3] == 1
&& node->src[0] ? std::string(node->src[0]->name).find(gemma3n_node_name) != std::string::npos : false
&& node->src[1] ? node->src[1]->name == gemma3n_per_layer_proj_src1_name : false)) {
// Generally, changes in batch size or context size can cause changes to the grid size of some kernels.
use_cuda_graph = false;
#ifndef NDEBUG
GGML_LOG_DEBUG("%s: disabling CUDA graphs due to batch size > 1 [%s] [%ld %ld %ld %ld]\n", __func__, node->name, node->ne[0], node->ne[1], node->ne[2], node->ne[3]);
GGML_LOG_INFO("%s: disabling CUDA graphs due to batch size > 1 [%s] [%ld %ld %ld %ld]\n", __func__, node->name, node->ne[0], node->ne[1], node->ne[2], node->ne[3]);
#endif
}