Fix sgl-kernel benchmark dead code (#11022)

sgl-kernel/benchmark/bench_lightning_attention_decode.py

@@ -1,11 +1,18 @@
 import itertools
 import math
+import os
 
 import torch
 import triton
 import triton.language as tl
 from sgl_kernel import lightning_attention_decode
 
+# CI environment detection
+IS_CI = (
+    os.getenv("CI", "false").lower() == "true"
+    or os.getenv("GITHUB_ACTIONS", "false").lower() == "true"
+)
+
 
 def next_power_of_2(n):
     return 2 ** (int(math.ceil(math.log(n, 2))))
@@ -207,7 +214,12 @@ def calculate_diff(batch_size):
         print("❌ Implementations differ")
 
 
-batch_size_range = [i for i in range(1, 65)]  # 1 to 128
+# Simplified for CI environment
+if IS_CI:
+    batch_size_range = [1]  # Single batch size for CI
+else:
+    batch_size_range = [i for i in range(1, 65)]  # 1 to 64
+
 configs = [(bs,) for bs in batch_size_range]
 
 
@@ -292,8 +304,9 @@ if __name__ == "__main__":
     )
     args = parser.parse_args()
 
-    # Run correctness test
-    calculate_diff(batch_size=4)
+    # Run correctness test - simplified for CI
+    test_batch_size = 1 if IS_CI else 4
+    calculate_diff(batch_size=test_batch_size)
 
     # Run performance benchmark
     benchmark.run(print_data=True)