Use an env var SGLANG_SET_CPU_AFFINITY to set cpu affinity; turn it off by default (#2222)

python/sglang/test/test_utils.py

@@ -22,7 +22,7 @@ from sglang.bench_serving import run_benchmark
 from sglang.global_config import global_config
 from sglang.lang.backend.openai import OpenAI
 from sglang.lang.backend.runtime_endpoint import RuntimeEndpoint
-from sglang.srt.utils import kill_child_process
+from sglang.srt.utils import get_bool_env_var, kill_child_process
 from sglang.test.run_eval import run_eval
 from sglang.utils import get_exception_traceback
 
@@ -44,7 +44,7 @@ DEFAULT_MODEL_NAME_FOR_NIGHTLY_EVAL_QUANT_TP1 = "hugging-quants/Meta-Llama-3.1-8
 
 def is_in_ci():
     """Return whether it is in CI runner."""
-    return os.getenv("SGLANG_IS_IN_CI", "false").lower() == "true"
+    return get_bool_env_var("SGLANG_IS_IN_CI")
 
 
 if is_in_ci():