log repeat twice

The log print in screen like 2021-04-28 17:55:36,274 - mmseg - INFO - Distributed training: True INFO:mmseg:Distributed training: True All log messages ware printed twice in screen, but in log files, the message was only writed once. I tried to locate the bug, and found that after run c = c.parent(anaconda3/envs/open-mmlab/lib/python3.7/logging/init.py, line 1590), c was changed to [StreamHandler <stderr> (NOTSET)]. And then, the message was print again.

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sys.platform: linux Python: 3.7.10 (default, Feb 26 2021, 18:47:35) [GCC 7.3.0] CUDA available: True GPU 0,1,2,3,4,5,6,7: GeForce RTX 3090 CUDA_HOME: /data/lfxuan/softwares/cuda-11.1 NVCC: Build cuda_11.1.TC455_06.29069683_0 GCC: gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0 PyTorch: 1.8.1+cu111 PyTorch compiling details: PyTorch built with:

• GCC 7.3
• C++ Version: 201402
• Intel® Math Kernel Library Version 2020.0.0 Product Build 20191122 for Intel® 64 architecture applications
• Intel® MKL-DNN v1.7.0 (Git Hash 7aed236906b1f7a05c0917e5257a1af05e9ff683)
• OpenMP 201511 (a.k.a. OpenMP 4.5)
• NNPACK is enabled
• CPU capability usage: AVX2
• CUDA Runtime 11.1
• NVCC architecture flags: -gencode;arch=compute_37,code=sm_37;-gencode;arch=compute_50,code=sm_50;-gencode;arch=compute_60,code=sm_60;-gencode;arch=compute_70,code=sm_70;-gencode;arch=compute_75,code=sm_75;-gencode;arch=compute_80,code=sm_80;-gencode;arch=compute_86,code=sm_86
• CuDNN 8.0.5
• Magma 2.5.2
• Build settings: BLAS_INFO=mkl, BUILD_TYPE=Release, CUDA_VERSION=11.1, CUDNN_VERSION=8.0.5, CXX_COMPILER=/opt/rh/devtoolset-7/root/usr/bin/c++, CXX_FLAGS= -Wno-deprecated -fvisibility-inlines-hidden -DUSE_PTHREADPOOL -fopenmp -DNDEBUG -DUSE_KINETO -DUSE_FBGEMM -DUSE_QNNPACK -DUSE_PYTORCH_QNNPACK -DUSE_XNNPACK -O2 -fPIC -Wno-narrowing -Wall -Wextra -Werror=return-type -Wno-missing-field-initializers -Wno-type-limits -Wno-array-bounds -Wno-unknown-pragmas -Wno-sign-compare -Wno-unused-parameter -Wno-unused-variable -Wno-unused-function -Wno-unused-result -Wno-unused-local-typedefs -Wno-strict-overflow -Wno-strict-aliasing -Wno-error=deprecated-declarations -Wno-stringop-overflow -Wno-psabi -Wno-error=pedantic -Wno-error=redundant-decls -Wno-error=old-style-cast -fdiagnostics-color=always -faligned-new -Wno-unused-but-set-variable -Wno-maybe-uninitialized -fno-math-errno -fno-trapping-math -Werror=format -Wno-stringop-overflow, LAPACK_INFO=mkl, PERF_WITH_AVX=1, PERF_WITH_AVX2=1, PERF_WITH_AVX512=1, TORCH_VERSION=1.8.1, USE_CUDA=ON, USE_CUDNN=ON, USE_EXCEPTION_PTR=1, USE_GFLAGS=OFF, USE_GLOG=OFF, USE_MKL=ON, USE_MKLDNN=ON, USE_MPI=OFF, USE_NCCL=ON, USE_NNPACK=ON, USE_OPENMP=ON,

TorchVision: 0.9.1+cu111 OpenCV: 4.5.1 MMCV: 1.3.2 MMCV Compiler: GCC 9.3 MMCV CUDA Compiler: 11.1 MMSegmentation: 0.9.0+fed4b96

[haotian-liu]

According to the discussion here, starting from version 1.8.0, PyTorch is calling to add a default RootLogger, which causes the logs being repeated twice.

So maybe we remove all of the log handlers when we get our first root logger?

[qizhuli]

I added logger.root.handlers.clear() after calling mmcv.utils.get_logger, and that fixes the duplicate logs problem for me.