add notes

deploy/cpp_infer/src/ocr_det.cpp

@@ -26,6 +26,7 @@ void DBDetector::LoadModel(const std::string &model_dir) {
     config.DisableGpu();
     if (this->use_mkldnn_) {
       config.EnableMKLDNN();
+      // cache 10 different shapes for mkldnn to avoid memory leak
       config.SetMkldnnCacheCapacity(10);
     }
     config.SetCpuMathLibraryNumThreads(this->cpu_math_library_num_threads_);

deploy/cpp_infer/src/ocr_rec.cpp

@@ -126,6 +126,7 @@ void CRNNRecognizer::LoadModel(const std::string &model_dir) {
     config.DisableGpu();
     if (this->use_mkldnn_) {
       config.EnableMKLDNN();
+      // cache 10 different shapes for mkldnn to avoid memory leak
       config.SetMkldnnCacheCapacity(10);
     }
     config.SetCpuMathLibraryNumThreads(this->cpu_math_library_num_threads_);

deploy/cpp_infer/tools/config.txt

@@ -3,7 +3,7 @@ use_gpu  0
 gpu_id  0
 gpu_mem  4000
 cpu_math_library_num_threads  10
-use_mkldnn 0
+use_mkldnn 1
 use_zero_copy_run 1
 
 # det config

tools/infer/utility.py

@@ -101,6 +101,7 @@ def create_predictor(args, mode):
         config.disable_gpu()
         config.set_cpu_math_library_num_threads(6)
         if args.enable_mkldnn:
+            # cache 10 different shapes for mkldnn to avoid memory leak
             config.set_mkldnn_cache_capacity(10)
             config.enable_mkldnn()