When i read the detail of function THNN_(SpatialConvolutionMM_updateGradInput), Could any warm-kinded people tell me the meaning of gradInput, gradOutput and gradColums and the correct order of reading Autograd mechanism used in Conv2d?
The argument grad_output is the gradient with respect to the output given by the autograd engine. grad_input is the tensor where the result should be written. grad_columns is a temporary buffer given here for efficiency.
The backward functions always take grad_output and return grad_input.