From 1e43b1da090ee058047dcef2eb7c71f19aeed17b Mon Sep 17 00:00:00 2001
From: Alexander Eichhorn <alex@eichhorn.dev>
Date: Thu, 15 Oct 2026 02:36:07 +0200
Subject: [PATCH 1/3] ci(tests): cut idle waits from the python suite and skip
 OS-independent tests on windows

Tests hash at bcrypt cost 4, shorten service queue polls, scope the move backoff to scripted failures, and freeze the heap before repeated gc passes.
Legacy-module symbol checks share one subprocess; a new platform_independent marker is deselected on windows only.
tests/AGENTS.md documents test cost and when the marker applies.
---
 .github/workflows/python-tests.yml            |  5 +-
 .../app/services/download/download_default.py |  5 +-
 .../model_install/model_install_default.py    | 12 +++-
 pyproject.toml                                |  1 +
 tests/AGENTS.md                               |  6 ++
 .../test_anima_qwen3_5_conditioning.py        |  1 +
 .../test_invocation_api_imports_alone.py      |  4 ++
 .../invocations/test_module_compatibility.py  | 65 ++++++++++---------
 .../app/services/auth/test_password_utils.py  |  2 +
 tests/app/services/auth/test_performance.py   |  4 ++
 .../image_index/test_image_index_service.py   |  9 ++-
 .../model_install/test_model_install.py       | 29 +++++----
 .../shared/test_for_scheduler_performance.py  |  1 +
 .../shared/test_graph_execution_runtime.py    |  3 +
 .../shared/test_graph_if_activation.py        |  1 +
 .../shared/test_graph_if_dependencies.py      |  1 +
 .../services/shared/test_graph_if_runtime.py  |  1 +
 .../shared/test_graph_iterate_planner.py      |  1 +
 .../shared/test_graph_materializer.py         |  1 +
 .../app/services/shared/test_graph_models.py  |  1 +
 .../shared/test_graph_runtime_records.py      |  3 +
 .../services/shared/test_graph_scheduler.py   |  3 +
 tests/app/test_database_access_guard.py       |  4 ++
 .../architectures/test_import_isolation.py    |  4 ++
 tests/backend/architectures/test_layering.py  |  4 ++
 .../test_model_cache_ram_budget.py            | 10 +++
 tests/backend/util/test_vae_tiling_scope.py   |  4 ++
 tests/conftest.py                             | 31 +++++++++
 tests/test_imports.py                         |  3 +
 tests/test_node_graph.py                      |  1 +
 30 files changed, 168 insertions(+), 52 deletions(-)

diff --git a/.github/workflows/python-tests.yml b/.github/workflows/python-tests.yml
index 11c8d591584..7eed10c0178 100644
--- a/.github/workflows/python-tests.yml
+++ b/.github/workflows/python-tests.yml
@@ -72,6 +72,9 @@ jobs:
             # runner with no spare core and the deadline-sensitive tests miss their budgets
             # non-deterministically. Two workers keep that headroom.
             pytest-workers: '2'
+            # Windows installs linux's dependency set, so a `platform_independent` test cannot fail differently
+            # here than on linux, which runs it. macOS runs a different torch without bitsandbytes and keeps them.
+            pytest-markers: 'not slow and not platform_independent'
             # Roughly 1.5x the pytest step's four-worker wall time (~13.5 min), plus the job's
             # ~1.5 min of checkout and install, plus margin.
             timeout-minutes: 45
@@ -155,7 +158,7 @@ jobs:
         # the vCPUs a standard runner exposes. Much of the suite waits on timers and polls, so
         # one worker per vCPU is the right level where the runner has the headroom for it. The
         # matrix carries the count, because windows needs a lower one.
-        run: uv run --no-sync pytest -n ${{ matrix.pytest-workers }} --max-worker-restart=0
+        run: uv run --no-sync pytest -n ${{ matrix.pytest-workers }} --max-worker-restart=0 -m "${{ matrix.pytest-markers || 'not slow' }}"
 
   # Decides whether the external-database job runs. That job's service containers start before any of its
   # steps, so the decision has to come from a job of its own: otherwise every pull request, frontend-only ones
diff --git a/invokeai/app/services/download/download_default.py b/invokeai/app/services/download/download_default.py
index 7fe1eceb9b1..4848f1935a8 100644
--- a/invokeai/app/services/download/download_default.py
+++ b/invokeai/app/services/download/download_default.py
@@ -45,6 +45,9 @@
 # Maximum number of bytes to download during each call to requests.iter_content()
 DOWNLOAD_CHUNK_SIZE = 100000
 
+# How long an idle worker blocks on the queue before rechecking the stop event, which bounds how long stop() waits.
+_QUEUE_POLL_SECONDS = 1.0
+
 
 class DownloadQueueService(DownloadQueueServiceBase):
     """Class for queued download of models."""
@@ -389,7 +392,7 @@ def _download_next_item(self) -> None:
                 done = True
                 continue
             try:
-                job = self._queue.get(timeout=1)
+                job = self._queue.get(timeout=_QUEUE_POLL_SECONDS)
             except Empty:
                 continue
             try:
diff --git a/invokeai/app/services/model_install/model_install_default.py b/invokeai/app/services/model_install/model_install_default.py
index 651ed29a9aa..20e6eebfcc0 100644
--- a/invokeai/app/services/model_install/model_install_default.py
+++ b/invokeai/app/services/model_install/model_install_default.py
@@ -109,6 +109,13 @@ class _InstallCancelledBeforeTransfer(Exception):
 # created; the combined name is only a label, so it is shortened past this point with a count.
 _MAX_COMBINED_SUBFOLDER_NAME = 96
 
+# How long the idle install thread blocks on its queue before rechecking the stop event, which bounds how long
+# stop() waits.
+_INSTALL_QUEUE_POLL_SECONDS = 1.0
+
+# First wait before retrying a move that hit a locked file; each further retry doubles it.
+_MOVE_RETRY_DELAY_SECONDS = 0.5
+
 
 def _combined_subfolder_name(subfolder_names: List[str]) -> str:
     combined = "_".join(subfolder_names)
@@ -800,8 +807,9 @@ def register_path(
     # TODO: Replace this with a proper fix for underlying problem of Windows holding open
     # the file when it needs to be moved.
     @staticmethod
-    def _move_with_retries(src: Path, dst: Path, attempts: int = 5, delay: float = 0.5) -> None:
+    def _move_with_retries(src: Path, dst: Path, attempts: int = 5) -> None:
         """Workaround for Windows file-handle issues when moving files."""
+        delay = _MOVE_RETRY_DELAY_SECONDS
         for tries_left in range(attempts, 0, -1):
             try:
                 move(src, dst)
@@ -1591,7 +1599,7 @@ def _install_next_item(self) -> None:
                 break
             self._logger.debug(f"Installer thread {threading.get_ident()} polling")
             try:
-                job = self._install_queue.get(timeout=1)
+                job = self._install_queue.get(timeout=_INSTALL_QUEUE_POLL_SECONDS)
             except Empty:
                 continue
             assert job.local_path is not None
diff --git a/pyproject.toml b/pyproject.toml
index c2617206361..6e0595aeb1c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -578,6 +578,7 @@ markers = [
   "timeout: Marks the timeout override.",
   "uses_database: Runs on the `empty_database` fixture, which targets INVOKEAI_TEST_DB_URL when it is set and SQLite otherwise. Applied by the collection hook in tests/conftest.py.",
   "sqlite_only: Depends on SQLite internals (query plans, PRAGMAs, the single connection); skipped when INVOKEAI_TEST_DB_URL targets another backend.",
+  "platform_independent: The outcome cannot depend on the operating system for the same dependency set: import-graph boundaries in a fresh interpreter, static source scans, deterministic counts and shapes. Windows CI, which installs the linux dependency set, deselects them.",
 ]
 # A cache-key or other SQLAlchemy warning is a bug in the query layer, not noise.
 filterwarnings = ["error::sqlalchemy.exc.SAWarning"]
diff --git a/tests/AGENTS.md b/tests/AGENTS.md
index 2ea50aedf67..b75684872b9 100644
--- a/tests/AGENTS.md
+++ b/tests/AGENTS.md
@@ -7,5 +7,11 @@
 - Cover affected rollback, revisions, cross-user isolation, retries, cancellation, bounds, and cleanup. IndexedDB, Web Locks, focus, and rendering belong in webv2 browser tests.
 - Use root pytest commands. CI runs xdist workers per vCPU, except windows, which runs fewer; `--dist loadfile` in `addopts` keeps each file on one worker, with arbitrary file assignment/order. Each file must establish its own process-global state (e.g. JWT secret) and pass alone; verify new files independently.
 - Default tests assert behavior, not throughput/latency under runner contention. Generous hang ceilings are acceptable; CPU time tolerates contention better than wall time. Hardware/quiet-machine measurements require `slow`, excluded by default and CI. On development machines, use `-m slow` for that lane or `-m ""` for everything.
+- Keep a test's run time to the work it checks; windows runs the suite on two workers, so idle seconds there set the CI wall clock. Check new files with `--durations=10`, which splits setup, call and teardown.
+  - No real waits. Poll intervals, retry backoffs and grace periods belong in module-level constants that a fixture can shorten. The root `conftest.py` already shortens the download, installer and image-index queue polls, so a service's `stop()` in teardown returns at once. Shorten a retry backoff only in the tests that script its failures, as `_fake_move` in `test_model_install.py` does: the backoff is what lets a real Windows file handle close.
+  - Passwords hash at bcrypt cost 4 in tests. Request `production_password_hashing` to assert or measure the production cost.
+  - A fresh interpreter costs about ten seconds of imports. Spawn one only when isolation is the point (import order, `sys.modules`, process-global state), and check many cases inside one subprocess unless each case needs its own cold start.
+  - A full `gc.collect()` walks the worker's whole heap, a third of a second late in a session. Tests that collect repeatedly freeze the pre-existing heap first, as `test_model_cache_ram_budget.py` does.
+- Mark a test `platform_independent` only when no operating system can change its outcome for the same dependency set: import-graph boundaries in a fresh interpreter, static source scans, deterministic counts or shapes. Windows CI, which installs the linux dependency set, deselects them; macOS runs a different torch and keeps them. Numerics (BLAS kernels differ per platform), process-spawning behavior (start methods, helper executables), filesystem paths and locking, and dependency smoke tests stay unmarked.
 - State hardware prerequisites and skipped/unavailable devices. CPU/mocked passes do not establish CUDA/ROCm/MPS/XPU behavior.
 - Do not run a CPU bf16 matmul unless low precision is the behavior under test: torch's CPU bf16 GEMM faults with an illegal instruction (`0xc000001d`) on part of the hosted windows fleet, which aborts the worker and fails the job. Run the forward at float32 and assert the width separately, as the nvfp4 loader tests do; skip on win32 only when bf16 itself is the subject.
diff --git a/tests/app/invocations/test_anima_qwen3_5_conditioning.py b/tests/app/invocations/test_anima_qwen3_5_conditioning.py
index 34fb231a0c6..b450fd58d53 100644
--- a/tests/app/invocations/test_anima_qwen3_5_conditioning.py
+++ b/tests/app/invocations/test_anima_qwen3_5_conditioning.py
@@ -75,6 +75,7 @@ def test_qwen3_5_is_read_at_the_trained_layers_with_an_attention_only_last_layer
     assert mask.tolist() == [True, True, True]
 
 
+@pytest.mark.platform_independent
 def test_the_prompt_node_does_not_import_transformers_qwen3_5_at_startup() -> None:
     """Every app start imports every node module; transformers' qwen3_5 modeling costs ~0.25 s of it."""
     program = (
diff --git a/tests/app/invocations/test_invocation_api_imports_alone.py b/tests/app/invocations/test_invocation_api_imports_alone.py
index 7aca72c1bd3..88100be974b 100644
--- a/tests/app/invocations/test_invocation_api_imports_alone.py
+++ b/tests/app/invocations/test_invocation_api_imports_alone.py
@@ -13,6 +13,10 @@
 import subprocess
 import sys
 
+import pytest
+
+pytestmark = pytest.mark.platform_independent
+
 PROGRAM = """
 import sys
 
diff --git a/tests/app/invocations/test_module_compatibility.py b/tests/app/invocations/test_module_compatibility.py
index 647becb0148..a04d1f801a1 100644
--- a/tests/app/invocations/test_module_compatibility.py
+++ b/tests/app/invocations/test_module_compatibility.py
@@ -8,6 +8,8 @@
 
 from invokeai.app.invocations._legacy_module_compatibility import LEGACY_MODULE_MAP
 
+pytestmark = pytest.mark.platform_independent
+
 
 def _run(program: str) -> dict[str, object]:
     result = subprocess.run([sys.executable, "-c", program], capture_output=True, text=True, timeout=300)
@@ -20,7 +22,29 @@ def test_compatibility_map_covers_all_moved_modules() -> None:
     assert len(set(LEGACY_MODULE_MAP.values())) == 106
 
 
+# A public symbol of each of these must be reachable through the legacy path, and be the canonical object.
+_REPRESENTATIVE_SYMBOLS = [
+    ("anima_denoise", "loglinear_timestep_shift"),
+    ("cogview4_denoise", "CogView4DenoiseInvocation"),
+    ("ernie_image_denoise", "ErnieImageDenoiseInvocation"),
+    ("flux_denoise", "FluxDenoiseInvocation"),
+    ("flux2_denoise", "Flux2DenoiseInvocation"),
+    ("ideogram4_caption", "Ideogram4Region"),
+    ("krea2_denoise", "Krea2DenoiseInvocation"),
+    ("minimax_h3_denoise", "MiniMaxH3DenoiseOutput"),
+    ("flux2_pid_decode", "Flux2PiDDecodeInvocation"),
+    ("qwen_image_denoise", "QwenImageDenoiseInvocation"),
+    ("controlnet", "ControlField"),
+    ("sd3_denoise", "SD3DenoiseInvocation"),
+    ("anima_text_encoder", "AnimaTextEncoderInvocation"),
+    ("anima_image_to_latents", "AnimaImageToLatentsInvocation"),
+    ("wan_denoise", "WanDenoiseInvocation"),
+    ("z_image_denoise", "ZImageDenoiseInvocation"),
+]
+
+
 def test_every_legacy_module_imports_and_aliases_canonical() -> None:
+    symbols = {f"invokeai.app.invocations.{legacy}": symbol for legacy, symbol in _REPRESENTATIVE_SYMBOLS}
     result = _run(
         f"""
 import importlib
@@ -35,20 +59,27 @@ def test_every_legacy_module_imports_and_aliases_canonical() -> None:
 logger.addHandler(handler)
 logger.setLevel(logging.INFO)
 mapping = {dict(LEGACY_MODULE_MAP)!r}
+symbols = {symbols!r}
 with warnings.catch_warnings(record=True) as caught:
     warnings.simplefilter("always")
     aliases = {{}}
+    broken_symbols = []
     for legacy, canonical in mapping.items():
         old = importlib.import_module(legacy)
         repeat = importlib.import_module(legacy)
-        aliases[legacy] = [old is importlib.import_module(canonical), repeat is old]
-print(json.dumps({{"aliases": aliases, "records": records, "deprecations": [
+        new = importlib.import_module(canonical)
+        aliases[legacy] = [old is new, repeat is old]
+        symbol = symbols.get(legacy)
+        if symbol is not None and getattr(old, symbol, None) is not getattr(new, symbol, object()):
+            broken_symbols.append(legacy + "." + symbol)
+print(json.dumps({{"aliases": aliases, "broken_symbols": broken_symbols, "records": records, "deprecations": [
     {{"message": str(w.message), "filename": str(w.filename)}}
     for w in caught if issubclass(w.category, DeprecationWarning)
 ]}}))
 """
     )
     assert result["aliases"] == {legacy: [True, True] for legacy in LEGACY_MODULE_MAP}
+    assert result["broken_symbols"] == []
     assert len(result["records"]) == len(LEGACY_MODULE_MAP)
     for legacy, canonical in LEGACY_MODULE_MAP.items():
         assert sum(legacy in record and canonical in record for record in result["records"]) == 1
@@ -81,36 +112,6 @@ def test_canonical_import_silent_unknown_path_stays_missing() -> None:
     assert result == {"missing": True, "records": []}
 
 
-@pytest.mark.parametrize(
-    ("legacy", "symbol"),
-    [
-        ("anima_denoise", "loglinear_timestep_shift"),
-        ("cogview4_denoise", "CogView4DenoiseInvocation"),
-        ("ernie_image_denoise", "ErnieImageDenoiseInvocation"),
-        ("flux_denoise", "FluxDenoiseInvocation"),
-        ("flux2_denoise", "Flux2DenoiseInvocation"),
-        ("ideogram4_caption", "Ideogram4Region"),
-        ("krea2_denoise", "Krea2DenoiseInvocation"),
-        ("minimax_h3_denoise", "MiniMaxH3DenoiseOutput"),
-        ("flux2_pid_decode", "Flux2PiDDecodeInvocation"),
-        ("qwen_image_denoise", "QwenImageDenoiseInvocation"),
-        ("controlnet", "ControlField"),
-        ("sd3_denoise", "SD3DenoiseInvocation"),
-        ("anima_text_encoder", "AnimaTextEncoderInvocation"),
-        ("anima_image_to_latents", "AnimaImageToLatentsInvocation"),
-        ("wan_denoise", "WanDenoiseInvocation"),
-        ("z_image_denoise", "ZImageDenoiseInvocation"),
-    ],
-)
-def test_representative_public_symbols_keep_identity(legacy: str, symbol: str) -> None:
-    old = f"invokeai.app.invocations.{legacy}"
-    canonical = LEGACY_MODULE_MAP[old]
-    result = _run(
-        f"import importlib, json; old = importlib.import_module({old!r}); new = importlib.import_module({canonical!r}); assert getattr(old, {symbol!r}) is getattr(new, {symbol!r}); print(json.dumps({{}}))"
-    )
-    assert result == {}
-
-
 def test_flux2_klein_text_encoder_legacy_import_explicitly_works() -> None:
     legacy = "invokeai.app.invocations.flux2_klein_text_encoder"
     canonical = LEGACY_MODULE_MAP[legacy]
diff --git a/tests/app/services/auth/test_password_utils.py b/tests/app/services/auth/test_password_utils.py
index 4f080c442d4..65f246faa31 100644
--- a/tests/app/services/auth/test_password_utils.py
+++ b/tests/app/services/auth/test_password_utils.py
@@ -286,6 +286,7 @@ class TestPasswordSecurityProperties:
     """Tests for security properties of password handling."""
 
     @pytest.mark.slow
+    @pytest.mark.usefixtures("production_password_hashing")
     def test_timing_attack_resistance_same_length(self):
         """Test that password verification takes similar time for correct and incorrect passwords.
 
@@ -334,6 +335,7 @@ def test_hash_output_format(self):
         # Bcrypt hashes are 60 characters long
         assert len(hashed) == 60
 
+    @pytest.mark.usefixtures("production_password_hashing")
     def test_hashing_cost_stays_at_a_defensible_work_factor(self):
         """The cost factor is what makes a stolen hash expensive to attack.
 
diff --git a/tests/app/services/auth/test_performance.py b/tests/app/services/auth/test_performance.py
index 63c4bc6d5e5..f77483a1445 100644
--- a/tests/app/services/auth/test_performance.py
+++ b/tests/app/services/auth/test_performance.py
@@ -32,6 +32,7 @@ def user_service(database: Database) -> UserService:
 
 
 @pytest.mark.slow
+@pytest.mark.usefixtures("production_password_hashing")
 class TestPasswordPerformance:
     """Tests for password hashing and verification performance."""
 
@@ -128,6 +129,7 @@ def test_token_verification_performance(self):
 
 
 @pytest.mark.slow
+@pytest.mark.usefixtures("production_password_hashing")
 class TestAuthenticationOverhead:
     """Tests for overall authentication system overhead."""
 
@@ -204,6 +206,7 @@ def test_token_verification_overhead(self):
 
 
 @pytest.mark.slow
+@pytest.mark.usefixtures("production_password_hashing")
 class TestUserServicePerformance:
     """Tests for user service performance."""
 
@@ -367,6 +370,7 @@ def authenticate_user(user_index: int):
 
 
 @pytest.mark.slow
+@pytest.mark.usefixtures("production_password_hashing")
 class TestScalabilityBenchmarks:
     """Sustained-load scalability benchmarks."""
 
diff --git a/tests/app/services/image_index/test_image_index_service.py b/tests/app/services/image_index/test_image_index_service.py
index 36a3d201baa..4d0bcc5b702 100644
--- a/tests/app/services/image_index/test_image_index_service.py
+++ b/tests/app/services/image_index/test_image_index_service.py
@@ -22,7 +22,6 @@
     _ACTIVATION_RETRY_INTERVAL_S,
     _MAX_ATTEMPTS,
     _MAX_BACKOFF_SECONDS,
-    _POLL_SECONDS,
     ImageIndexService,
 )
 from invokeai.app.services.image_index.image_index_records_default import ImageIndexRecords
@@ -1188,11 +1187,11 @@ def encode(images: list[Image.Image]) -> np.ndarray:
 
 def test_systemic_backoff_grows_and_is_capped(service: ImageIndexService) -> None:
     service._systemic_failures = 0
-    assert service._backoff_seconds() == _POLL_SECONDS
+    assert service._backoff_seconds() == image_index_default._POLL_SECONDS
     service._systemic_failures = 1
-    assert service._backoff_seconds() == _POLL_SECONDS
+    assert service._backoff_seconds() == image_index_default._POLL_SECONDS
     service._systemic_failures = 3
-    assert service._backoff_seconds() == _POLL_SECONDS * 4
+    assert service._backoff_seconds() == image_index_default._POLL_SECONDS * 4
     # Capped, and no overflow for an outage that lasts a very long time.
     service._systemic_failures = 10_000
     assert service._backoff_seconds() == _MAX_BACKOFF_SECONDS
@@ -1399,7 +1398,7 @@ def flaky_upsert(item, model_id, embedding):
             assert service._process_batch(imgs("stored.png", "locked.png")) is False
 
         assert service._systemic_failures == 0, "progress must clear the outage counter"
-        assert service._backoff_seconds() == _POLL_SECONDS, "a draining index must not back off"
+        assert service._backoff_seconds() == image_index_default._POLL_SECONDS, "a draining index must not back off"
         # The half that stored is stored, and no image was charged an attempt.
         assert index_records.get_embeddings(imgs("stored.png"), MODEL_ID)[0] == imgs("stored.png")
         assert service._failed == set()
diff --git a/tests/app/services/model_install/test_model_install.py b/tests/app/services/model_install/test_model_install.py
index 2639a1d3f51..d9b15f9e3b2 100644
--- a/tests/app/services/model_install/test_model_install.py
+++ b/tests/app/services/model_install/test_model_install.py
@@ -13,7 +13,7 @@
 import uuid
 from pathlib import Path
 from types import SimpleNamespace
-from typing import Any, Dict
+from typing import Any, Callable, Dict
 from unittest.mock import MagicMock
 
 import pytest
@@ -72,6 +72,13 @@
 OS = platform.uname().system
 
 
+def _fake_move(monkeypatch: pytest.MonkeyPatch, move: Callable[[Path, Path], object]) -> None:
+    """Install a move that fails on purpose. Its failures are scripted, so the retry backoff, which gives a real
+    Windows file handle time to close, would only add sleep."""
+    monkeypatch.setattr(model_install_default, "move", move)
+    monkeypatch.setattr(model_install_default, "_MOVE_RETRY_DELAY_SECONDS", 0.0)
+
+
 def test_registration(mm2_installer: ModelInstallServiceBase, embedding_file: Path) -> None:
     store = mm2_installer.record_store
     matches = store.search_by_attr(model_name="test_embedding")
@@ -179,7 +186,7 @@ def copy_then_fail_unlink(src: Path, dst: Path):
             raise PermissionError("simulated Windows source unlink failure")
         return real_move(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", copy_then_fail_unlink)
+    _fake_move(monkeypatch, copy_then_fail_unlink)
 
     key = mm2_installer.install_path(embedding_file)
 
@@ -484,7 +491,7 @@ def flaky_move(src: Path, dst: Path):
             raise PermissionError("simulated Windows file-handle race")
         return real_move(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", flaky_move)
+    _fake_move(monkeypatch, flaky_move)
 
     key = mm2_installer.install_path(diffusers_dir)
 
@@ -508,7 +515,7 @@ def test_directory_install_failure_does_not_leave_partial_destination(
     def fail_first_move(_src: Path, _dst: Path):
         raise PermissionError("simulated Windows file-handle race")
 
-    monkeypatch.setattr(model_install_default, "move", fail_first_move)
+    _fake_move(monkeypatch, fail_first_move)
 
     with pytest.raises(PermissionError, match="simulated Windows file-handle race"):
         mm2_installer.install_path(diffusers_dir)
@@ -543,7 +550,7 @@ def move_with_locked_source(src: Path, dst: Path):
             moved_first_item = True
         return result
 
-    monkeypatch.setattr(model_install_default, "move", move_with_locked_source)
+    _fake_move(monkeypatch, move_with_locked_source)
 
     with pytest.raises(PermissionError, match="source file remains locked"):
         mm2_installer.install_path(diffusers_dir)
@@ -588,7 +595,7 @@ def move_with_recreated_source(src: Path, dst: Path):
             raise FileExistsError(dst)
         return real_move(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", move_with_recreated_source)
+    _fake_move(monkeypatch, move_with_recreated_source)
 
     with pytest.raises(RuntimeError, match="recovery required") as exc_info:
         mm2_installer.install_path(diffusers_dir)
@@ -631,7 +638,7 @@ def partial_copy_then_fail(src: Path, dst: Path) -> None:
         dst.write_bytes(partial_destination_bytes)
         raise OSError(errno.ENOSPC, "simulated disk full")
 
-    monkeypatch.setattr(model_install_default, "move", partial_copy_then_fail)
+    _fake_move(monkeypatch, partial_copy_then_fail)
 
     job = installer.import_model(LocalModelSource(path=source_path, inplace=False))
     installer.wait_for_job(job, timeout=10)
@@ -692,7 +699,7 @@ def recreate_after_absence_check(src: Path, dst: Path) -> None:
             dst.write_bytes(b"new user bytes")
         real_rename_noreplace(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", fail_later_move)
+    _fake_move(monkeypatch, fail_later_move)
     monkeypatch.setattr(ModelInstallService, "_rename_noreplace", staticmethod(recreate_after_absence_check))
 
     with pytest.raises(model_install_default.InstallRecoveryRequiredError, match="recovery required"):
@@ -722,7 +729,7 @@ def partial_copy_then_fail(src: Path, dst: Path):
             raise PermissionError("copy failed after destination creation")
         return shutil.move(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", partial_copy_then_fail)
+    _fake_move(monkeypatch, partial_copy_then_fail)
 
     with pytest.raises(RuntimeError, match="recovery required") as exc_info:
         mm2_installer.install_path(diffusers_dir)
@@ -747,7 +754,7 @@ def fail_after_unowned_destination_artifact(src: Path, dst: Path):
             raise PermissionError("later source remains locked")
         return shutil.move(src, dst)
 
-    monkeypatch.setattr(model_install_default, "move", fail_after_unowned_destination_artifact)
+    _fake_move(monkeypatch, fail_after_unowned_destination_artifact)
 
     with pytest.raises(RuntimeError, match="recovery required") as exc_info:
         mm2_installer.install_path(diffusers_dir)
@@ -803,7 +810,7 @@ def sorted_source_files(path: Path):
         return iter(sorted(entries, key=lambda entry: entry.name)) if path == tmpdir else iter(entries)
 
     monkeypatch.setattr(Path, "iterdir", sorted_source_files)
-    monkeypatch.setattr(model_install_default, "move", fail_after_partial_transfer)
+    _fake_move(monkeypatch, fail_after_partial_transfer)
     real_write_install_marker = mm2_installer._write_install_marker
 
     def fail_recovery_marker(job_arg, *args, **kwargs):
diff --git a/tests/app/services/shared/test_for_scheduler_performance.py b/tests/app/services/shared/test_for_scheduler_performance.py
index c2de4d3706c..d58b2c0f5a3 100644
--- a/tests/app/services/shared/test_for_scheduler_performance.py
+++ b/tests/app/services/shared/test_for_scheduler_performance.py
@@ -146,6 +146,7 @@ def _run_trivial_loop(
     return clock() - started
 
 
+@pytest.mark.platform_independent
 @pytest.mark.parametrize(
     ("loop_type", "include_if", "external_condition"),
     [
diff --git a/tests/app/services/shared/test_graph_execution_runtime.py b/tests/app/services/shared/test_graph_execution_runtime.py
index d5b0ee11fd9..b0c00e531dc 100644
--- a/tests/app/services/shared/test_graph_execution_runtime.py
+++ b/tests/app/services/shared/test_graph_execution_runtime.py
@@ -2,10 +2,13 @@
 import sys
 import textwrap
 
+import pytest
+
 from invokeai.app.services.shared import graph as graph_facade
 from invokeai.app.services.shared import graph_execution_runtime
 
 
+@pytest.mark.platform_independent
 def test_runtime_module_imports_without_graph_cycle() -> None:
     script = textwrap.dedent(
         """
diff --git a/tests/app/services/shared/test_graph_if_activation.py b/tests/app/services/shared/test_graph_if_activation.py
index f2cfc39deed..90827e48521 100644
--- a/tests/app/services/shared/test_graph_if_activation.py
+++ b/tests/app/services/shared/test_graph_if_activation.py
@@ -74,6 +74,7 @@ def _is_activation_dependency_rejected(self, dependency: ActivationDependency) -
         return dependency in self.rejected
 
 
+@pytest.mark.platform_independent
 def test_standalone_import_does_not_import_graph() -> None:
     assert_module_imports_without_graph("invokeai.app.services.shared.graph_if_activation")
 
diff --git a/tests/app/services/shared/test_graph_if_dependencies.py b/tests/app/services/shared/test_graph_if_dependencies.py
index b77f7f90206..a1004553b3f 100644
--- a/tests/app/services/shared/test_graph_if_dependencies.py
+++ b/tests/app/services/shared/test_graph_if_dependencies.py
@@ -227,6 +227,7 @@ def _indirectly_connected_if_graph() -> Graph:
     return graph
 
 
+@pytest.mark.platform_independent
 def test_leaf_import_does_not_import_graph() -> None:
     assert_module_imports_without_graph("invokeai.app.services.shared.graph_if_dependencies")
 
diff --git a/tests/app/services/shared/test_graph_if_runtime.py b/tests/app/services/shared/test_graph_if_runtime.py
index ad596f2812a..7a8c72abbe7 100644
--- a/tests/app/services/shared/test_graph_if_runtime.py
+++ b/tests/app/services/shared/test_graph_if_runtime.py
@@ -20,6 +20,7 @@ def state() -> GraphExecutionState:
     return state
 
 
+@pytest.mark.platform_independent
 def test_runtime_import_without_graph() -> None:
     assert_module_imports_without_graph("invokeai.app.services.shared.graph_if_runtime")
 
diff --git a/tests/app/services/shared/test_graph_iterate_planner.py b/tests/app/services/shared/test_graph_iterate_planner.py
index 9e4e1016276..e98e430c389 100644
--- a/tests/app/services/shared/test_graph_iterate_planner.py
+++ b/tests/app/services/shared/test_graph_iterate_planner.py
@@ -6,6 +6,7 @@
 import pytest
 
 
+@pytest.mark.platform_independent
 @pytest.mark.parametrize("planner_first", [True, False])
 def test_planner_import_boundary(planner_first: bool) -> None:
     script = textwrap.dedent(
diff --git a/tests/app/services/shared/test_graph_materializer.py b/tests/app/services/shared/test_graph_materializer.py
index e407af81998..f5c28118e86 100644
--- a/tests/app/services/shared/test_graph_materializer.py
+++ b/tests/app/services/shared/test_graph_materializer.py
@@ -9,6 +9,7 @@
 from invokeai.app.services.shared import graph as graph_facade
 
 
+@pytest.mark.platform_independent
 def test_materializer_import_is_leaf_and_keeps_networkx_lazy() -> None:
     script = textwrap.dedent(
         """
diff --git a/tests/app/services/shared/test_graph_models.py b/tests/app/services/shared/test_graph_models.py
index f6211956c81..9ab948b1db7 100644
--- a/tests/app/services/shared/test_graph_models.py
+++ b/tests/app/services/shared/test_graph_models.py
@@ -293,6 +293,7 @@ def test_graph_models_preserve_heterogeneous_control_flow_roundtrip() -> None:
     assert isinstance(restored_state.execution_graph.nodes["return"], ForReturnInvocation)
 
 
+@pytest.mark.platform_independent
 def test_graph_models_preserve_lazy_networkx_and_registry_behavior() -> None:
     script = """
     import builtins
diff --git a/tests/app/services/shared/test_graph_runtime_records.py b/tests/app/services/shared/test_graph_runtime_records.py
index 82d7bd45e2a..689018af729 100644
--- a/tests/app/services/shared/test_graph_runtime_records.py
+++ b/tests/app/services/shared/test_graph_runtime_records.py
@@ -2,10 +2,13 @@
 import sys
 import textwrap
 
+import pytest
+
 from invokeai.app.services.shared import graph as graph_facade
 from invokeai.app.services.shared import graph_runtime_records
 
 
+@pytest.mark.platform_independent
 def test_runtime_records_import_without_graph_cycle() -> None:
     script = textwrap.dedent(
         """
diff --git a/tests/app/services/shared/test_graph_scheduler.py b/tests/app/services/shared/test_graph_scheduler.py
index da40f6b90da..f5984381dba 100644
--- a/tests/app/services/shared/test_graph_scheduler.py
+++ b/tests/app/services/shared/test_graph_scheduler.py
@@ -1,6 +1,8 @@
 import subprocess
 import sys
 
+import pytest
+
 from invokeai.app.services.shared import graph as graph_module
 from invokeai.app.services.shared import graph_scheduler
 
@@ -10,6 +12,7 @@ def test_graph_facade_reexports_scheduler_classes() -> None:
     assert graph_module._GenericGraphSchedulerAdapter is graph_scheduler._GenericGraphSchedulerAdapter
 
 
+@pytest.mark.platform_independent
 def test_graph_scheduler_import_does_not_import_graph_facade() -> None:
     result = subprocess.run(
         [
diff --git a/tests/app/test_database_access_guard.py b/tests/app/test_database_access_guard.py
index 59e113d4fc3..43dc4e0c9c6 100644
--- a/tests/app/test_database_access_guard.py
+++ b/tests/app/test_database_access_guard.py
@@ -11,6 +11,10 @@
 from dataclasses import dataclass
 from pathlib import Path
 
+import pytest
+
+pytestmark = pytest.mark.platform_independent
+
 REPO_ROOT = Path(__file__).resolve().parents[2]
 SCANNED_ROOTS = ("invokeai", "scripts")
 DATABASE_LAYER = (
diff --git a/tests/backend/architectures/test_import_isolation.py b/tests/backend/architectures/test_import_isolation.py
index e2db7e9d9e0..d31a1379a75 100644
--- a/tests/backend/architectures/test_import_isolation.py
+++ b/tests/backend/architectures/test_import_isolation.py
@@ -13,8 +13,12 @@
 mean this never runs in CI.
 """
 
+import pytest
+
 from tests.dangerously_run_function_in_subprocess import dangerously_run_function_in_subprocess
 
+pytestmark = pytest.mark.platform_independent
+
 
 def _registry_is_full_after_importing_dependencies() -> None:
     # No arguments and no closure: the whole function body is re-executed in a fresh interpreter, so
diff --git a/tests/backend/architectures/test_layering.py b/tests/backend/architectures/test_layering.py
index b2f9ca0f67b..c4e426fdcc6 100644
--- a/tests/backend/architectures/test_layering.py
+++ b/tests/backend/architectures/test_layering.py
@@ -18,6 +18,10 @@
 from collections.abc import Iterable
 from pathlib import Path
 
+import pytest
+
+pytestmark = pytest.mark.platform_independent
+
 REPO_ROOT = Path(__file__).parents[3]
 ARCH = "invokeai.backend.architectures"
 ARCH_DIR = "invokeai/backend/architectures"
diff --git a/tests/backend/model_manager/load/model_cache/test_model_cache_ram_budget.py b/tests/backend/model_manager/load/model_cache/test_model_cache_ram_budget.py
index bc186af4794..646445fb2f1 100644
--- a/tests/backend/model_manager/load/model_cache/test_model_cache_ram_budget.py
+++ b/tests/backend/model_manager/load/model_cache/test_model_cache_ram_budget.py
@@ -41,6 +41,16 @@ def mock_logger():
     return logger
 
 
+@pytest.fixture(autouse=True)
+def _collect_only_this_tests_objects():
+    """These tests call gc.collect() to run finalizers, often once per loop iteration. A full collection walks
+    the whole heap of the worker process, a third of a second deep into a session. Freezing what existed before
+    the test leaves every collection to the objects the test created, which is where its garbage lives."""
+    gc.freeze()
+    yield
+    gc.unfreeze()
+
+
 def _make_cache(store, budget, logger, keep_ram_copy=True) -> ModelCache:
     return ModelCache(
         execution_device_working_mem_gb=1.0,
diff --git a/tests/backend/util/test_vae_tiling_scope.py b/tests/backend/util/test_vae_tiling_scope.py
index d944ec94a3a..669db6d713d 100644
--- a/tests/backend/util/test_vae_tiling_scope.py
+++ b/tests/backend/util/test_vae_tiling_scope.py
@@ -111,6 +111,7 @@ def test_entering_with_tiling_already_on_turns_it_off_and_puts_it_back(self):
 
         assert (vae.use_tiling, vae.tile_sample_min_size, vae.tile_latent_min_size) == before
 
+    @pytest.mark.platform_independent
     def test_every_tile_size_the_field_accepts_assembles_the_full_latent(self):
         """The decode sweep below, pointed at the encode.
 
@@ -141,6 +142,7 @@ def test_the_vaes_own_geometry_is_restored(self):
 
         assert (vae.use_tiling, vae.tile_sample_min_size, vae.tile_latent_min_size) == before
 
+    @pytest.mark.platform_independent
     def test_every_tile_size_the_field_accepts_assembles_the_full_image(self):
         """A sweep over every value the node field accepts, on the class that can fail it.
 
@@ -164,6 +166,7 @@ def test_every_tile_size_the_field_accepts_assembles_the_full_image(self):
 
         assert not wrong
 
+    @pytest.mark.platform_independent
     @pytest.mark.parametrize("overlap_factor", [0.125, 0.2, 0.3, 1 / 3, 0.35])
     def test_a_non_stock_overlap_factor_is_honoured_rather_than_assumed(self, overlap_factor):
         """Which tiles a factor admits depends on how it rounds in binary, not on its value.
@@ -183,6 +186,7 @@ def test_a_non_stock_overlap_factor_is_honoured_rather_than_assumed(self, overla
             with torch.no_grad(), scoped_vae_tiling(vae, tile_size):
                 assert vae.decode(latent, return_dict=False)[0].shape == (1, 3, 512, 512)
 
+    @pytest.mark.platform_independent
     def test_a_decode_at_the_vaes_default_resolution_actually_tiles(self):
         """The case the missing size costs: a 1024px decode against a VAE whose default tile is also
         1024 stays in the single-pass path, which is the one the reservation was sized against."""
diff --git a/tests/conftest.py b/tests/conftest.py
index badeaca0e79..9bf75bc752a 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -11,6 +11,7 @@
 
 import pytest
 
+from invokeai.app.services.auth import password_utils
 from invokeai.app.services.board_image_records.board_image_records_default import BoardImageRecordStorage
 from invokeai.app.services.board_records.board_records_default import BoardRecordStorage
 from invokeai.app.services.board_video_records.board_video_records_default import BoardVideoRecordStorage
@@ -18,8 +19,10 @@
 from invokeai.app.services.bulk_download.bulk_download_default import BulkDownloadService
 from invokeai.app.services.client_state_persistence.client_state_persistence_default import ClientStatePersistence
 from invokeai.app.services.config.config_default import InvokeAIAppConfig
+from invokeai.app.services.download import download_default
 from invokeai.app.services.external_generation.external_generation_default import ExternalGenerationService
 from invokeai.app.services.gallery.gallery_default import GalleryService
+from invokeai.app.services.image_index import image_index_default
 from invokeai.app.services.image_index.image_index_default import ImageIndexService
 from invokeai.app.services.image_index.image_index_records_default import ImageIndexRecords
 from invokeai.app.services.image_records.image_records_default import ImageRecordStorage
@@ -30,6 +33,7 @@
 from invokeai.app.services.invocation_services import InvocationServices
 from invokeai.app.services.invocation_stats.invocation_stats_default import InvocationStatsService
 from invokeai.app.services.invoker import Invoker
+from invokeai.app.services.model_install import model_install_default
 from invokeai.app.services.project_records.project_records_default import ProjectRecordsStorage
 from invokeai.app.services.shared.database.database import Database
 from invokeai.app.services.system_prompt_records.system_prompt_records_default import (
@@ -79,6 +83,33 @@ def _clear_deferred_empty_cache():
     TorchDevice._empty_cache_deferred.clear()
 
 
+_PRODUCTION_PASSWORD_CONTEXT = password_utils.pwd_context
+_TEST_PASSWORD_CONTEXT = _PRODUCTION_PASSWORD_CONTEXT.copy(bcrypt__rounds=4)
+
+
+@pytest.fixture(autouse=True)
+def _cheap_password_hashing(monkeypatch: pytest.MonkeyPatch) -> None:
+    """At the production cost factor every user a test creates or logs in costs a fifth of a second, which
+    was most of the multiuser router tests' run time. Cost-4 hashes still round-trip, and stored cost-12
+    hashes still verify. Tests about the cost itself request `production_password_hashing`."""
+    monkeypatch.setattr(password_utils, "pwd_context", _TEST_PASSWORD_CONTEXT)
+
+
+@pytest.fixture
+def production_password_hashing(monkeypatch: pytest.MonkeyPatch) -> None:
+    """Hash at the production cost factor, for tests that assert or measure it."""
+    monkeypatch.setattr(password_utils, "pwd_context", _PRODUCTION_PASSWORD_CONTEXT)
+
+
+@pytest.fixture(autouse=True)
+def _fast_service_polling(monkeypatch: pytest.MonkeyPatch) -> None:
+    """Idle service workers poll their queues once a second, so every stop() in a fixture teardown waited up to
+    that long. Shortening the intervals keeps the same loops and orderings; it only removes the idle wait."""
+    monkeypatch.setattr(download_default, "_QUEUE_POLL_SECONDS", 0.02)
+    monkeypatch.setattr(model_install_default, "_INSTALL_QUEUE_POLL_SECONDS", 0.02)
+    monkeypatch.setattr(image_index_default, "_POLL_SECONDS", 0.02)
+
+
 @pytest.fixture
 def mock_sqlite_database() -> Database:
     """The in-memory database behind `mock_services`, for tests that need SQL of their own or a service that
diff --git a/tests/test_imports.py b/tests/test_imports.py
index 48889bf3dd8..e464f19cbaf 100644
--- a/tests/test_imports.py
+++ b/tests/test_imports.py
@@ -4,6 +4,8 @@
 import sys
 import textwrap
 
+import pytest
+
 import invokeai
 
 KNOWN_IMPORT_ERRORS = {
@@ -38,6 +40,7 @@ def test_invokeai_imports():
     assert not failed_to_import, f"Modules failed to import: {failed_to_import}"
 
 
+@pytest.mark.platform_independent
 def test_graph_module_import_does_not_require_networkx():
     script = """
     import builtins
diff --git a/tests/test_node_graph.py b/tests/test_node_graph.py
index d06a1905cb5..6efc2fcfcb8 100644
--- a/tests/test_node_graph.py
+++ b/tests/test_node_graph.py
@@ -2743,6 +2743,7 @@ def invoke(self) -> str:
                 return "foo"
 
 
+@pytest.mark.platform_independent
 def test_nodes_must_return_invocation_output_under_optimized_python():
     result = subprocess.run(
         [

From d213bf5e4fa807546d5ff4727e0bde1b36e2e518 Mon Sep 17 00:00:00 2001
From: Alexander Eichhorn <alex@eichhorn.dev>
Date: Thu, 15 Oct 2026 02:50:12 +0200
Subject: [PATCH 2/3] test(video): trim the open-GOP source only around its
 I-frames

Reads the source's key frames and trims around each open-GOP I-frame instead of from all 40 starts.
Asserts read_h264_layout offers no open-GOP I-frame as a cut point, which the old loop did not catch.
---
 .../test_video_frame_extract_range.py         | 33 +++++++++++++++++--
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/tests/app/invocations/test_video_frame_extract_range.py b/tests/app/invocations/test_video_frame_extract_range.py
index 1cd2dec8dfd..6bec7b32fa9 100644
--- a/tests/app/invocations/test_video_frame_extract_range.py
+++ b/tests/app/invocations/test_video_frame_extract_range.py
@@ -7,19 +7,22 @@
 stops decoding as soon as the range is written.
 """
 
+import re
 import shutil
+import subprocess
 from pathlib import Path
 from typing import Iterator
 from unittest.mock import MagicMock, patch
 
 import imageio.v2 as iio2
+import imageio_ffmpeg
 import numpy as np
 import pytest
 
 from invokeai.app.invocations.fields import VideoField
 from invokeai.app.invocations.video_frame_extract_range import ExtractVideoRangeInvocation, _write_frame_range
 from invokeai.app.services.session_processor.session_processor_common import CanceledException
-from invokeai.app.util.h264_splice import read_h264_layout
+from invokeai.app.util.h264_splice import MIN_ENCODED_FRAMES, read_h264_layout
 from invokeai.app.util.mp4_metadata import read_mp4_tags, write_mp4_tags
 from invokeai.app.util.video_encoding import make_mp4_writer
 from invokeai.app.util.video_thumbnails import probe_video
@@ -150,6 +153,19 @@ def test_invocation_echoes_the_source_video_it_was_given() -> None:
     assert output.video.video_name == "output.mp4"
 
 
+def _key_frames(path: Path) -> list[int]:
+    """Display indices of the key frames, as the decoder reports them."""
+    result = subprocess.run(
+        [imageio_ffmpeg.get_ffmpeg_exe(), "-hide_banner", "-i", str(path), "-vf", "showinfo", "-f", "null", "-"],
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+        errors="replace",
+        check=True,
+    )
+    return [int(n) for n, key in re.findall(r"\bn:\s*(\d+)\b.*?\biskey:(\d)", result.stderr) if key == "1"]
+
+
 def _decode(path: Path) -> list[np.ndarray]:
     reader = iio2.get_reader(str(path), format="FFMPEG")
     try:
@@ -314,8 +330,19 @@ def test_open_gop_source_trim_keeps_every_frame(tmp_path: Path) -> None:
         writer.append_data(frame)
     writer.close()
 
-    # Every start in the last two GOPs, so one lands on an open-GOP I-frame wherever x264 put it.
-    for start in range(60, 100):
+    layout = read_h264_layout(source)
+    assert layout is not None
+    open_gop_frames = [n for n in _key_frames(source) if n >= 60]
+    assert open_gop_frames, "x264 placed no keyframe in the last two GOPs"
+    # Only the IDR is a clean cut; offering an open-GOP I-frame as one is the regression this guards.
+    assert layout.sync_samples == (0,), f"cut points {layout.sync_samples} include an open-GOP I-frame"
+
+    # Around each open-GOP I-frame of the last two GOPs: a cut on it, a head of MIN_ENCODED_FRAMES
+    # or more before it, a head too short to keep, and a start just past it. The window is wide
+    # enough for the I-frame's decode position, which leading B-frames put up to two before its
+    # display position, so every way of treating it as a cut point is exercised.
+    starts = sorted({s for p in open_gop_frames for s in range(p - MIN_ENCODED_FRAMES - 2, p + 2) if s < 100})
+    for start in starts:
         saved, _ = _invoke_trim(tmp_path, source, start, 99)
         assert len(_decode(saved)) == 100 - start, f"trim from {start}"
 

From 0a54b0b99e6d440142463845a1672d48c4fda729 Mon Sep 17 00:00:00 2001
From: Alexander Eichhorn <alex@eichhorn.dev>
Date: Thu, 15 Oct 2026 21:59:40 +0200
Subject: [PATCH 3/3] test(session-processor): give the woken worker time for
 its gc pass

A woken worker runs a full gc.collect() before taking its item, which late in an xdist session can exceed the 2 s join.
Polls every 60 s with a 10 s deadline, so a pass still requires the release listener.
---
 .../test_lent_device_scheduling.py                 | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tests/app/services/session_processor/test_lent_device_scheduling.py b/tests/app/services/session_processor/test_lent_device_scheduling.py
index d9eb2cf2060..032ff35b61e 100644
--- a/tests/app/services/session_processor/test_lent_device_scheduling.py
+++ b/tests/app/services/session_processor/test_lent_device_scheduling.py
@@ -24,6 +24,12 @@
 GPU0 = torch.device("cuda:0")
 GPU1 = torch.device("cuda:1")
 
+# A woken worker still runs a full gc.collect() before it takes its item, which late in an xdist
+# session can take seconds. The poll interval stays far above this deadline, so a pass still
+# needs the release listener rather than the poll.
+_POLLING_INTERVAL_S = 60
+_WAKE_DEADLINE_S = 10
+
 
 @pytest.fixture(autouse=True)
 def pool() -> Iterator[None]:
@@ -65,7 +71,7 @@ def get_queue_item(self, item_id: int):
             configuration=SimpleNamespace(multiuser=False, clear_vram_after_session=False),
         )
     )
-    processor._polling_interval = 5  # long enough that only the release listener can wake it in time
+    processor._polling_interval = _POLLING_INTERVAL_S
     processor._thread_semaphore = BoundedSemaphore(1)
     processor._poll_now_event = Event()
     GENERATION_DEVICE_POOL.set_release_listener(processor._poll_now_event.set)
@@ -93,8 +99,8 @@ def test_worker_leaves_items_alone_while_its_gpu_is_lent_and_resumes_on_release(
         assert claims == []  # nothing claimed onto the lent GPU
 
         GENERATION_DEVICE_POOL.release_borrow(GPU0)
-        # The release wakes the worker at once; its 5 s poll interval would fail this join.
-        thread.join(timeout=2)
+        # The release wakes the worker at once; waiting for its poll interval would fail this join.
+        thread.join(timeout=_WAKE_DEADLINE_S)
         assert not thread.is_alive()
         assert claims == ["cuda:0"]
     finally:
@@ -108,7 +114,7 @@ def test_worker_on_a_free_gpu_claims_while_another_is_lent() -> None:
 
     thread, stop_event, claims, processor = _start_worker(GPU1)
     try:
-        thread.join(timeout=2)
+        thread.join(timeout=_WAKE_DEADLINE_S)
         assert not thread.is_alive()
         assert claims == ["cuda:1"]
     finally: