[Hardware] Replace torch.cuda.empty_cache with torch.accelerator.empty_cache (#30681)

Signed-off-by: Kunshang Ji <kunshang.ji@intel.com>
Signed-off-by: Kunshang Ji <jikunshang95@gmail.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

tools/pre_commit/check_torch_cuda.py

@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import sys
+
+import regex as re
+
+# --------------------------------------------------------------------------- #
+# Regex: match `torch.cuda.xxx` but allow `torch.accelerator.xxx`
+# --------------------------------------------------------------------------- #
+_TORCH_CUDA_PATTERNS = [
+    r"\btorch\.cuda\.empty_cache\b",
+]
+
+ALLOWED_FILES = {"vllm/platforms/", "vllm/device_allocator/"}
+
+
+def scan_file(path: str) -> int:
+    with open(path, encoding="utf-8") as f:
+        content = f.read()
+    for pattern in _TORCH_CUDA_PATTERNS:
+        for match in re.finditer(pattern, content, re.MULTILINE):
+            # Calculate line number from match position
+            line_num = content[: match.start() + 1].count("\n") + 1
+            print(
+                f"{path}:{line_num}: "
+                "\033[91merror:\033[0m "  # red color
+                "Found torch.cuda API call"
+            )
+            return 1
+    return 0
+
+
+def main():
+    returncode = 0
+    for filename in sys.argv[1:]:
+        if any(filename.startswith(prefix) for prefix in ALLOWED_FILES):
+            continue
+        returncode |= scan_file(filename)
+    return returncode
+
+
+if __name__ == "__main__":
+    sys.exit(main())