context : pad the total context to 256

Author: ggerganov

include/llama.h

@@ -463,6 +463,7 @@ extern "C" {
 
     // NOTE: After creating a llama_context, it is recommended to query the actual values using these functions
     //       In some cases the requested values via llama_context_params may differ from the actual values used by the context
+    //       ref: https://github.com/ggml-org/llama.cpp/pull/17046#discussion_r2503085732
     LLAMA_API uint32_t llama_n_ctx      (const struct llama_context * ctx);
     LLAMA_API uint32_t llama_n_ctx_seq  (const struct llama_context * ctx);
     LLAMA_API uint32_t llama_n_batch    (const struct llama_context * ctx);

src/llama-context.cpp

@@ -112,10 +112,14 @@ llama_context::llama_context(
         }
     }
 
+    // ref: https://github.com/ggml-org/llama.cpp/pull/17046#discussion_r2503085732
+    cparams.n_ctx = GGML_PAD(cparams.n_ctx, 256);
+
     if (cparams.kv_unified) {
         cparams.n_ctx_seq = cparams.n_ctx;
     } else {
         cparams.n_ctx_seq = cparams.n_ctx / cparams.n_seq_max;
+        cparams.n_ctx_seq = GGML_PAD(cparams.n_ctx_seq, 256);
 
         if (cparams.n_ctx_seq == 0) {
             throw std::runtime_error("n_ctx_seq == 0");