server : print graphs reused in slot timings (#23279)

Add graphs reused counter to the per-slot timing output, printed via
llama_perf_context().

Assisted-by: llama.cpp:local pi

Co-authored-by: ggerganov <ggerganov@users.noreply.github.com>

Author: ggerganov

tools/server/server-context.cpp

@@ -467,20 +467,26 @@ struct server_slot {
         const double n_gen_second = 1e3 / t_token_generation * n_decoded;
 
         SLT_INF(*this,
-                "\n"
-                "prompt eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n"
-                "       eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n"
+                "prompt eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n",
+                t_prompt_processing, n_prompt_tokens_processed, t_prompt, n_prompt_second);
+
+        SLT_INF(*this,
+                "       eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n",
+                t_token_generation, n_decoded, t_gen, n_gen_second);
+
+        SLT_INF(*this,
                 "      total time = %10.2f ms / %5d tokens\n",
-                t_prompt_processing, n_prompt_tokens_processed, t_prompt, n_prompt_second,
-                t_token_generation, n_decoded, t_gen, n_gen_second,
                 t_prompt_processing + t_token_generation, n_prompt_tokens_processed + n_decoded);
 
+        SLT_INF(*this,
+                "   graphs reused = %10d\n",
+                llama_perf_context(ctx_tgt).n_reused);
+
         if (n_draft_total > 0) {
             const float draft_ratio = (float) n_draft_accepted / n_draft_total;
-            SLT_CNT(*this,
-                    "draft acceptance rate = %0.5f (%5d accepted / %5d generated)\n",
-                    draft_ratio, n_draft_accepted, n_draft_total
-            );
+            SLT_INF(*this,
+                    "draft acceptance = %0.5f (%5d accepted / %5d generated)\n",
+                    draft_ratio, n_draft_accepted, n_draft_total);
         }
 
         common_speculative_print_stats(spec);