Add an option to set number of warmup iterations (#27739)

paddle/fluid/inference/tests/api/tester_helper.h

@@ -65,6 +65,7 @@ DEFINE_bool(zero_copy, false, "Use ZeroCopy to speedup Feed/Fetch.");
 DEFINE_bool(warmup, false,
             "Use warmup to calculate elapsed_time more accurately. "
             "To reduce CI time, it sets false in default.");
+DEFINE_int32(warmup_iters, 1, "Number of batches to process during warmup.");
 
 DEFINE_bool(enable_profile, false, "Turn on profiler for fluid");
 DEFINE_int32(cpu_num_threads, 1, "Number of threads for each paddle instance.");
@@ -364,15 +365,28 @@ void PredictionWarmUp(PaddlePredictor *predictor,
   if (FLAGS_zero_copy) {
     ConvertPaddleTensorToZeroCopyTensor(predictor, inputs[0]);
   }
-  outputs->resize(1);
+  int iterations = 1;
+  if (FLAGS_warmup_iters > 1)
+    iterations = std::min(FLAGS_warmup_iters, static_cast<int>(inputs.size()));
+  outputs->resize(iterations);
   Timer warmup_timer;
-  warmup_timer.tic();
+  double elapsed_time = 0;
   if (!FLAGS_zero_copy) {
-    predictor->Run(inputs[0], &(*outputs)[0], batch_size);
+    for (int i = 0; i < iterations; ++i) {
+      warmup_timer.tic();
+      predictor->Run(inputs[i], &(*outputs)[i], batch_size);
+      elapsed_time += warmup_timer.toc();
+    }
   } else {
+    for (int i = 0; i < iterations; ++i) {
+      warmup_timer.tic();
       predictor->ZeroCopyRun();
+      elapsed_time += warmup_timer.toc();
+    }
   }
-  PrintTime(batch_size, 1, num_threads, tid, warmup_timer.toc(), 1, data_type);
+  auto batch_latency = elapsed_time / iterations;
+  PrintTime(batch_size, 1, num_threads, tid, batch_latency, iterations,
+            data_type);
   if (FLAGS_enable_profile) {
     paddle::platform::ResetProfiler();
   }