From df0b4434e90e72ff7ac4cef3b7365deb71925865 Mon Sep 17 00:00:00 2001 From: Lijunhui <1578034415@qq.com> Date: Thu, 24 Feb 2022 16:52:13 +0800 Subject: [PATCH] Optimize nearest_interp backward (#39067) * nearest_interp_bw init * optimize kernel config * optimize kernel config * fix struct init * optimize code * rm duplicated struct --- paddle/fluid/operators/interpolate_v2_op.cu | 102 ++++++++++++++------ 1 file changed, 73 insertions(+), 29 deletions(-) diff --git a/paddle/fluid/operators/interpolate_v2_op.cu b/paddle/fluid/operators/interpolate_v2_op.cu index 6e9d6a19954..d61eb46d97e 100644 --- a/paddle/fluid/operators/interpolate_v2_op.cu +++ b/paddle/fluid/operators/interpolate_v2_op.cu @@ -210,32 +210,66 @@ __global__ void KeNearestNeighbor3DInterpFw( } } +template +__global__ void KeNearestNeighborInterpNCHWBw( + T* in, const size_t in_img_h, const size_t in_img_w, const T* out, + const size_t out_img_h, const size_t out_img_w, const size_t nc, + const float ratio_h, const float ratio_w, const bool align_corners) { + int out_img_idx = threadIdx.x + blockIdx.x * blockDim.x; + int out_img_idy = threadIdx.y + blockIdx.y * blockDim.y; + int nc_id = threadIdx.z + blockIdx.z * blockDim.z; + int nc_stride = blockDim.z * gridDim.z; + + // nearest_sampling by multiple read in_addr and write to out_addr + int in_img_idx = (align_corners) + ? static_cast(ratio_w * out_img_idx + 0.5) + : static_cast(ratio_w * out_img_idx); + int in_img_idy = (align_corners) + ? static_cast(ratio_h * out_img_idy + 0.5) + : static_cast(ratio_h * out_img_idy); + + int in_index = (nc_id * in_img_h + in_img_idy) * in_img_w + in_img_idx; + int in_index_stride = nc_stride * in_img_h * in_img_w; + + int out_index = (nc_id * out_img_h + out_img_idy) * out_img_w + out_img_idx; + int out_index_stride = nc_stride * out_img_h * out_img_w; + + // prevent from multiple threads writing + if (out_img_idx < out_img_w && out_img_idy < out_img_h) { + while (nc_id < nc) { + T* in_pos = &in[in_index]; + const T out_pos = out[out_index]; + platform::CudaAtomicAdd(in_pos, out_pos); + in_index += in_index_stride; + out_index += out_index_stride; + nc_id += nc_stride; + } + } +} + template __global__ void KeNearestNeighborInterpBw( T* in, const size_t in_img_h, const size_t in_img_w, const size_t input_h, const size_t input_w, const T* out, const size_t out_img_h, const size_t out_img_w, const size_t output_h, const size_t output_w, const size_t num_channels, const float ratio_h, const float ratio_w, - const bool align_corners, const DataLayout data_layout) { + const bool align_corners, FastDivModForInterpolate divmods) { int nthreads = output_h * output_w; int tid = blockIdx.x * blockDim.x + threadIdx.x; int stride = blockDim.x * gridDim.x; + int in_img_size = in_img_h * in_img_w; + int out_img_size = out_img_h * out_img_w; + for (; tid < nthreads; tid += stride) { - int out_id_h = tid / output_w; - int out_id_w = tid % output_w; - int in_img_size = input_w / num_channels; - int out_img_size = output_w / num_channels; + auto out_id_divmod = divmods.output_w_div.Divmod(tid); + int out_id_h = out_id_divmod.val[0]; + int out_id_w = out_id_divmod.val[1]; - int channel_id, out_img_idy, out_img_idx; - if (data_layout == DataLayout::kNCHW) { - channel_id = out_id_w / out_img_size; - out_img_idy = (out_id_w % out_img_size) / out_img_w; - out_img_idx = tid % out_img_w; - } else { - out_img_idy = out_id_w / (out_img_w * num_channels); - out_img_idx = out_id_w % (out_img_w * num_channels) / num_channels; - channel_id = tid % num_channels; - } + int channel_id = divmods.channels_div.Divmod(tid).val[1]; + auto outimg_id_divmod = divmods.output_wc_div.Divmod(out_id_w); + int out_img_idy = outimg_id_divmod.val[0]; + int out_img_idx = + divmods.channels_div.Divmod(outimg_id_divmod.val[1]).val[0]; int in_img_idy = (align_corners) ? static_cast(ratio_h * out_img_idy + 0.5) @@ -244,15 +278,10 @@ __global__ void KeNearestNeighborInterpBw( ? static_cast(ratio_w * out_img_idx + 0.5) : static_cast(ratio_w * out_img_idx); - T* in_pos; - if (data_layout == DataLayout::kNCHW) { - in_pos = &in[out_id_h * input_w + channel_id * in_img_size + - in_img_idy * in_img_w + in_img_idx]; - } else { - in_pos = &in[out_id_h * input_w + in_img_idy * in_img_w * num_channels + - in_img_idx * num_channels + channel_id]; - } - const T out_pos = out[out_id_h * output_w + out_id_w]; + T* in_pos = &in[out_id_h * input_w + in_img_idy * in_img_w * num_channels + + in_img_idx * num_channels + channel_id]; + + const T out_pos = out[tid]; platform::CudaAtomicAdd(in_pos, out_pos); } } @@ -1842,11 +1871,26 @@ static void Interpolate2DCUDABwd(const framework::ExecutionContext& ctx, platform::GetGpuLaunchConfig1D(ctx.cuda_device_context(), pixelNum); if ("nearest" == interp_method) { - KeNearestNeighborInterpBw< - T><<>>( - input_grad_data, in_h, in_w, n, in_chw, output_grad_data, out_h, out_w, - n, out_chw, c, ratio_h, ratio_w, align_corners, data_layout); + if (data_layout == DataLayout::kNCHW) { + // get launch 3D config + int nc = n * c; + platform::GpuLaunchConfig config_3d = + GetGpuLaunchConfig3D(ctx.cuda_device_context(), nc, out_h, out_w); + KeNearestNeighborInterpNCHWBw< + T><<>>( + input_grad_data, in_h, in_w, output_grad_data, out_h, out_w, nc, + ratio_h, ratio_w, align_corners); + } else { + int64_t cw = c * out_w; + auto interp_divmods = FastDivModForInterpolate(c, out_chw, cw); + KeNearestNeighborInterpBw< + T><<>>( + input_grad_data, in_h, in_w, n, in_chw, output_grad_data, out_h, + out_w, n, out_chw, c, ratio_h, ratio_w, align_corners, + interp_divmods); + } } else if ("bilinear" == interp_method) { const T align_type_value = (align_mode == 0 && !align_corners) ? 0.5f : 0; bool is_nchw = (data_layout == DataLayout::kNCHW) ? true : false; -- GitLab