add env vars & misc

README.md

@@ -27,6 +27,10 @@ docker build -t vllm-ascend-multi-llm:latest -f ./Dockerfile .
 2. Start LLM services with this image, following the official usage instructions.
 3. Due to the limited stream resource of Ascend NPU, you may need to restrict graph capture sizes or disable ACLgraph by setting `--enforce-eager`, especially when launching multiple LLMs. Refer to the [link](https://docs.vllm.ai/projects/ascend/en/latest/faqs.html#how-to-troubleshoot-and-resolve-size-capture-failures-resulting-from-stream-resource-exhaustion-and-what-are-the-underlying-causes).
 
+### Environment Variables
+- `VNPU_RESERVED_VRAM_SIZE_GB`: The amonut of reserved GPU memory for other miscellaneous memory. Only needs to be set for `vllm_vnpu_daemon`. Try increasing the variable if you launch multiple LLM services and encounter OOM. Default: `8`.
+- `VLLM_VNPU_SHM_NAME`: The name of the shm file. Needs to be set for all containers of the shared vNPU group. Default: `/vllm_acl_vnpu_offload_shm`.
+
 
 ## Limitations