message: Improve message when engine creation fails. Remove spammy warning
diff: @@ -376,7 +376,7 @@ void TRTEngineOp::ComputeAsync(OpKernelContext* ctx,
  }
  EngineContext* engine_context = GetEngine(input_shapes, ctx);
  if (!engine_context->cuda_engine) {
  - LOG(WARNING) << "Engine retrieval for input shapes: "
  + VLOG(1) << "Engine retrieval for input shapes: "
  << TensorShapeUtils::ShapeListString(input_shapes)
  << " failed. Running native segment for " << name();
  ExecuteNativeSegment(ctx, helper);
  @@ -625,17 +625,12 @@ EngineContext* TRTEngineOp::GetEngine(
  partial_shapes, &logger, allocator, calibrator_.get(), &engine,
  use_calibration_, &convert_successfully);
  if (!status.ok()) {
  - if (convert_successfully) {
  - // This means it fail to build the engine even when the network is built
  - // successfully, probably due to internal issues. In this case we don't
  - // retry in the future.
  + LOG(WARNING) << "Engine creation for " << name() << " failed. "
  + << "The native segment will be used instead. "
  + << "Reason: " << status;
  + // Store an empty engine in the cache for these input shapes so we don't
  + // try to build the same failing engine again.
  cache.emplace(engine_input_shapes, absl::make_unique<EngineContext>());
  - }
  - LOG(WARNING) << "Engine creation for batch size " << batch_size
  - << " failed " << status;
  - // Store an empty engine here so we don't try to build the same engine
  - // again.
  - cache.emplace(engine_input_shapes, empty_context);
  return &empty_context;
  }
  VLOG(1) << "Conversion is done";
  