Document the `CUPY_CUDA_PER_THREAD_DEFAULT_STREAM` environment variable
@@ -85,6 +85,15 @@ Here are the environment variables CuPy uses.
| | RawKernels/RawModules with ``nvcc`` backend or |
| | when using ``cub`` as the accelerator. |
+------------------------------------------------+----------------------------------------------------+
+| ``CUPY_CUDA_PER_THREAD_DEFAULT_STREAM`` | If set to 1, CuPy will use the CUDA per-thread |
+| | default stream, effectively causing each host |
+| | thread to automatically execute in its own stream, |
+| | unless the CUDA default (``null``) stream or |
+| | a user-created stream is specified. If set to 0 |
+| | (default), the CUDA default (``null``) stream is |
+| | used, unless the per-thread default stream |
+| | (``ptds``) or a user-created stream is specified. |
++------------------------------------------------+----------------------------------------------------+
Moreover, as in any CUDA programs, all of the CUDA environment variables listed in the `CUDA Toolkit
Documentation`_ will also be honored. When ``CUPY_ACCELERATORS`` or ``NVCC`` environment variables
