env var for disabling kernels

vllm/model_executor/layers/quantization/kernels/__init__.py

@@ -1,3 +1,4 @@
+import os
 from typing import List, Optional, Type
 
 from vllm.platforms import current_platform
@@ -24,6 +25,12 @@ def choose_mp_linear_kernel(
 
     failure_reasons = []
     for kernel in _POSSIBLE_KERNELS:
+        if kernel.__name__ in os.environ.get("VLLM_DISABLED_KERNELS", "")\
+            .split(","):
+            failure_reasons.append(
+                f' {kernel.__name__} disabled by environment variable')
+            continue
+
         if kernel.get_min_capability() > compute_capability:
             failure_reasons.append(
                 f"{kernel.__name__} requires capability "
@@ -35,8 +42,7 @@ def choose_mp_linear_kernel(
             return kernel
         else:
             failure_reasons.append(
-                f' {kernel.__name__} cannot implement due to: {failure_reason}'
-            )
+                f' {kernel.__name__} cannot implement due to: {failure_reason}')
 
     raise ValueError(
         "Failed to find a kernel that can implement the "\