llama : make tensor_split ptr instead of array (#2272)

Author: ggerganov

examples/common.cpp

@@ -586,7 +586,7 @@ struct llama_context_params llama_context_params_from_gpt_params(const gpt_param
     lparams.n_batch      = params.n_batch;
     lparams.n_gpu_layers = params.n_gpu_layers;
     lparams.main_gpu     = params.main_gpu;
-    memcpy(lparams.tensor_split, params.tensor_split, LLAMA_MAX_DEVICES*sizeof(float));
+    lparams.tensor_split = params.tensor_split;
     lparams.low_vram     = params.low_vram;
     lparams.seed         = params.seed;
     lparams.f16_kv       = params.memory_f16;

ggml-cuda.cu

@@ -2512,6 +2512,9 @@ void ggml_init_cublas() {
 }
 
 void ggml_cuda_set_tensor_split(const float * tensor_split) {
+    if (tensor_split == nullptr) {
+        return;
+    }
     bool all_zero = true;
     for (int i = 0; i < g_device_count; ++i) {
         if (tensor_split[i] != 0.0f) {

llama.cpp

@@ -849,7 +849,7 @@ struct llama_context_params llama_context_default_params() {
         /*.n_batch                     =*/ 512,
         /*.gpu_layers                  =*/ 0,
         /*.main_gpu                    =*/ 0,
-        /*.tensor_split                =*/ {0},
+        /*.tensor_split                =*/ nullptr,
         /*.rope_freq_base              =*/ 10000.0f,
         /*.rope_freq_scale             =*/ 1.0f,
         /*.progress_callback           =*/ nullptr,
@@ -1289,7 +1289,7 @@ static bool llama_model_load(
         int n_batch,
         int n_gpu_layers,
         int main_gpu,
-        float * tensor_split,
+        const float * tensor_split,
         float rope_freq_base,
         float rope_freq_scale,
         bool low_vram,

llama.h

@@ -88,7 +88,8 @@ extern "C" {
         int32_t  n_batch;                      // prompt processing batch size
         int32_t  n_gpu_layers;                 // number of layers to store in VRAM
         int32_t  main_gpu;                     // the GPU that is used for scratch and small tensors
-        float tensor_split[LLAMA_MAX_DEVICES]; // how to split layers across multiple GPUs
+
+        const float * tensor_split; // how to split layers across multiple GPUs (size: LLAMA_MAX_DEVICES)
 
         // ref: https://github.com/ggerganov/llama.cpp/pull/2054
         float    rope_freq_base;  // RoPE base frequency