From 8df937a4f7007a18bcfdd4b202581036229b93a4 Mon Sep 17 00:00:00 2001
From: Jason Wen <haibin.wen3@gmail.com>
Date: Wed, 19 Aug 2026 23:22:57 -0400
Subject: [PATCH] modeld_v2: stage onnx to disk instead of shared memory

---
 .../sunnypilot/modeld_v2/compile_modeld.py    | 23 ++++++------
 .../modeld_v2/tests/test_compile_modeld.py    | 37 ++++++++++++++++++-
 2 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/openpilot/sunnypilot/modeld_v2/compile_modeld.py b/openpilot/sunnypilot/modeld_v2/compile_modeld.py
index 927e5f3392..85ae57c078 100755
--- a/openpilot/sunnypilot/modeld_v2/compile_modeld.py
+++ b/openpilot/sunnypilot/modeld_v2/compile_modeld.py
@@ -272,18 +272,17 @@ def _parse_size(size_str: str) -> tuple[int, int]:
   return int(width), int(height)
 
 
-def read_file_chunked_to_shm(path):
+def read_file_chunked_to_disk(path):
   if not path:
     return None
   import atexit
   import shutil
   from openpilot.common.file_chunker import open_file_chunked
-  from openpilot.common.hardware.hw import Paths
-  shm_path = os.path.join(Paths.shm_path(), os.path.basename(path))
-  atexit.register(lambda: os.path.exists(shm_path) and os.remove(shm_path))
-  with open(shm_path, 'wb') as dst, open_file_chunked(path) as src:
-    shutil.copyfileobj(src, dst)
-  return shm_path
+  tmp_path = f'{path}.unchunked'
+  with open(tmp_path, 'wb') as f, open_file_chunked(path) as src:
+    shutil.copyfileobj(src, f)
+  atexit.register(lambda: os.path.exists(tmp_path) and os.remove(tmp_path))
+  return tmp_path
 
 
 def _load_policy_runners(args: argparse.Namespace) -> tuple[list, list]:
@@ -327,11 +326,11 @@ if __name__ == "__main__":
   model_w, model_h = args.model_size
   output_data = {}
 
-  args.vision_onnx = read_file_chunked_to_shm(args.vision_onnx)
-  args.policy_onnx = read_file_chunked_to_shm(args.policy_onnx)
-  args.off_policy_onnx = read_file_chunked_to_shm(args.off_policy_onnx)
-  args.on_policy_onnx = read_file_chunked_to_shm(args.on_policy_onnx)
-  args.supercombo_onnx = read_file_chunked_to_shm(args.supercombo_onnx)
+  args.vision_onnx = read_file_chunked_to_disk(args.vision_onnx)
+  args.policy_onnx = read_file_chunked_to_disk(args.policy_onnx)
+  args.off_policy_onnx = read_file_chunked_to_disk(args.off_policy_onnx)
+  args.on_policy_onnx = read_file_chunked_to_disk(args.on_policy_onnx)
+  args.supercombo_onnx = read_file_chunked_to_disk(args.supercombo_onnx)
 
   vision_runner = OnnxRunner(args.vision_onnx) if args.vision_onnx else None
 
diff --git a/openpilot/sunnypilot/modeld_v2/tests/test_compile_modeld.py b/openpilot/sunnypilot/modeld_v2/tests/test_compile_modeld.py
index 885696b853..96bfb42638 100644
--- a/openpilot/sunnypilot/modeld_v2/tests/test_compile_modeld.py
+++ b/openpilot/sunnypilot/modeld_v2/tests/test_compile_modeld.py
@@ -5,10 +5,15 @@ This file is part of sunnypilot and is licensed under the MIT License.
 See the LICENSE.md file in the root directory for more details.
 """
 
+import os
+import tempfile
+from pathlib import Path
+
 import numpy as np
 from openpilot.common.parameterized import parameterized
 
-from openpilot.sunnypilot.modeld_v2.compile_modeld import derive_frame_skip, _detect_desire_key
+from openpilot.common.file_chunker import chunk_file, get_chunk_targets
+from openpilot.sunnypilot.modeld_v2.compile_modeld import derive_frame_skip, _detect_desire_key, read_file_chunked_to_disk
 from openpilot.common.test import OpenpilotTestCase
 
 
@@ -160,3 +165,33 @@ class TestOutputSlicePreservation(OpenpilotTestCase):
     policy_slices = {'plan': slice(0, 495), 'meta': slice(495, 550)}
     assert set(vision_slices.keys()) & set(policy_slices.keys()) == set(), \
       "vision and policy slices should not overlap in keys"
+
+
+class TestReadFileChunkedToDisk(OpenpilotTestCase):
+  def test_none_passthrough(self):
+    assert read_file_chunked_to_disk(None) is None
+
+  def test_unchunked_source_staged_on_disk(self):
+    with tempfile.TemporaryDirectory() as d:
+      src = Path(d) / "driving_supercombo.onnx"
+      payload = os.urandom(1024)
+      src.write_bytes(payload)
+
+      out = Path(read_file_chunked_to_disk(str(src)))
+
+      assert out.parent == Path(d)
+      assert out.name == "driving_supercombo.onnx.unchunked"
+      assert out.read_bytes() == payload
+
+  def test_chunked_source_reassembled_on_disk(self):
+    with tempfile.TemporaryDirectory() as d:
+      src = Path(d) / "driving_supercombo.onnx"
+      payload = os.urandom(4096)
+      src.write_bytes(payload)
+      chunk_file(str(src), get_chunk_targets(str(src), len(payload)))
+      assert not src.exists()
+
+      out = Path(read_file_chunked_to_disk(str(src)))
+
+      assert out.parent == Path(d)
+      assert out.read_bytes() == payload