Profiler result is not consistent with each run

[RavikumarLav]

Hello,

i am using below code part to capture the runtime for model inference

// Import the TensorFlow model. Note: use CreateNetworkFromBinaryFile for .pb files.
armnnTfLiteParser::ITfLiteParserPtr parser = armnnTfLiteParser::ITfLiteParser::Create();

armnn::INetworkPtr network = parser->CreateNetworkFromBinaryFile("model_latest.tflite");

// Find the binding points for the input and output nodes  
armnnTfLiteParser::BindingPointInfo inputBindingInfo = parser->GetNetworkInputBindingInfo(0, "conv2d_input");
armnnTfLiteParser::BindingPointInfo outputBindingInfo = parser->GetNetworkOutputBindingInfo(0, "Identity");

// Create ArmNN runtime
armnn::IRuntime::CreationOptions options; // default options
armnn::IRuntimePtr runtime = armnn::IRuntime::Create(options);

armnn::Compute device= armnn::Compute::CpuAcc; 
//armnn::Compute device= armnn::Compute::CpuRef;
armnn::IOptimizedNetworkPtr optNet = Optimize(*network, {device}, runtime->GetDeviceSpec()); 
// Load the optimized network onto the runtime device
armnn::NetworkId networkIdentifier;
runtime->LoadNetwork(networkIdentifier, std::move(optNet));

// Create a profiler and register it for the current thread.
std::shared_ptrarmnn::IProfiler profiler = runtime->GetProfiler(networkIdentifier);
profiler->EnableProfiling(true);

// Enable profiling.
profiler->EnableProfiling(true);

// Run Inference
armnn::InputTensors inputTensor = MakeInputTensors(inputBindingInfo, &input[0]);
armnn::OutputTensors outputTensor = MakeOutputTensors(outputBindingInfo, &output[0]);
armnn::Status ret = runtime->EnqueueWorkload(networkIdentifier, inputTensor, outputTensor);

// Print output
profiler->Print(std::cout);

able to see json format of each layer profiler result .

Problem: Running .tflite model on arm a78 core with CpuAcc as the option the runtime is different for each run of same model.

for one of model it is varying from 0.8 to 1.2ms

Need to know how runtime is calculating using system clock or by using arm registers