Why do CUDA asynchronous errors occur? （occur on the linux OS）

Question

CUDA kernel errors might be asynchronously reported at some other API call, so the stacktrace below might be incorrect. For debugging consider passing CUDA_LAUNCH_BLOCKING=1. Compile with TORCH_USE_CUDA_DSA to enable device-side assertions.

I try the enter the command in the bash: export CUDA_LAUNCH_BLOCKING=1 and it worked. However, I am not sure whether this way affects the GPU(s) efficiency or not. Can I change some setting to make it the default such that I do not have to type this command line every time?