clock cudaMalloc cudaMemcpy cudaFree whole ./ ../ ../../../Common Performance Strategies performance timing CUDA clock timer true clock.cu 1:CUDA Basic Topics 1:Performance Strategies sm50 sm52 sm53 sm60 sm61 sm70 sm72 sm75 sm80 sm86 sm87 sm90 x86_64 linux windows7 x86_64 macosx arm sbsa ppc64le linux all exe