[Test][KV Connector] Add request_finished fence population tests for offloading scheduler (#45679)

Signed-off-by: Alex <alex.tech.lab@outlook.com>
Signed-off-by: AlexHuang <jihuihuang@future.com>
Co-authored-by: Or Ozeri <oro@il.ibm.com>
This commit is contained in:
AlexHuang
2026-06-18 08:13:52 +03:00
committed by GitHub
co-authored by Or Ozeri
parent 421c1ec448
commit 554352a311
2 changed files with 302 additions and 9 deletions
@@ -906,9 +906,27 @@ def test_fence_at_update_state_after_alloc(request_runner):
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.run(decoded_tokens=[EOS_TOKEN_ID], complete_transfers=False)
# Capture fence snapshots to verify block 0 is registered.
fence_snapshots: list[dict] = []
def capture_fence():
fence_snapshots.append(
dict(runner.connector_scheduler._block_id_to_pending_jobs)
)
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
complete_transfers=False,
post_step_fn=capture_fence,
)
assert runner.connector_scheduler._block_id_to_pending_jobs
# Verify fence was populated with the store job's block IDs.
populated_fence = next((f for f in fence_snapshots if f), None)
assert populated_fence is not None, "Fence was never populated"
assert len(populated_fence) > 0, "Fence is empty"
runner.scheduler.reset_prefix_cache()
runner.new_request(token_ids=[0] * 4)
runner.connector_scheduler._maximal_prefix_lookup = lambda key, req_context: 1
@@ -939,9 +957,27 @@ def test_fence_at_build_store_jobs(request_runner):
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.run(decoded_tokens=[EOS_TOKEN_ID], complete_transfers=False)
# Capture fence snapshots to verify block 0 is registered.
fence_snapshots: list[dict] = []
def capture_fence():
fence_snapshots.append(
dict(runner.connector_scheduler._block_id_to_pending_jobs)
)
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
complete_transfers=False,
post_step_fn=capture_fence,
)
assert runner.connector_scheduler._block_id_to_pending_jobs
# Verify fence was populated with the store job's block IDs.
populated_fence = next((f for f in fence_snapshots if f), None)
assert populated_fence is not None, "Fence was never populated"
assert len(populated_fence) > 0, "Fence is empty"
runner.scheduler.reset_prefix_cache()
runner.new_request(token_ids=[1] * 4)
runner.connector_scheduler._maximal_prefix_lookup = lambda key, req_context: 0
@@ -1021,8 +1057,8 @@ def test_max_offload_tokens_validation(request_runner, async_scheduling: bool):
token_ids=[0] * offloaded_block_size * 3,
kv_transfer_params={"max_offload_tokens": max_offload_tokens},
)
r.manager.prepare_store.side_effect = (
lambda keys, req_context: generate_store_output(keys)
r.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
# Pending offloads drain via non-blocking stepping, not a flush, so no
@@ -1120,8 +1156,8 @@ def test_offload_prompt_only(request_runner, async_scheduling: bool):
extra_config_overrides={"offload_prompt_only": True},
)
runner.manager.prepare_store.side_effect = (
lambda keys, req_context: generate_store_output(keys)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.new_request(token_ids=[0] * offloaded_block_size * num_prompt_blocks)
@@ -2182,3 +2218,249 @@ class TestEagle:
(1, 1),
),
)
# ---------------------------------------------------------------------------
# Tests for request_finished fence population with in-flight pending stores.
# ---------------------------------------------------------------------------
def test_request_finished_with_pending_stores_populates_fence(request_runner):
"""When a request finishes with in-flight store jobs, the fence index
(_block_id_to_pending_jobs) is correctly populated with the store jobs'
non_sliding_window_block_ids.
This prevents data corruption when a subsequent request reuses the same
GPU blocks before the store completes.
"""
block_size = 4
block_size_factor = 1
offloaded_block_size = block_size * block_size_factor
# Use 2 GPU blocks so the second run reuses the same blocks,
# triggering a fence-based flush of the in-flight job from run 1.
runner = request_runner(
block_size=block_size,
num_gpu_blocks=2,
async_scheduling=False,
block_size_factor=block_size_factor,
)
# 4 prompt tokens → 1 GPU block (block 0)
runner.new_request(token_ids=[0] * offloaded_block_size)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
# Capture fence state at each step to verify it was populated.
fence_snapshots: list[dict] = []
job_block_ids: set[int] = set()
def capture_fence():
fence_snapshots.append(
dict(runner.connector_scheduler._block_id_to_pending_jobs)
)
for js in runner.connector_scheduler._jobs.values():
if js.is_store:
job_block_ids.update(js.non_sliding_window_block_ids or [])
# Run 1: create store job, finish request, populate fence.
# With non-blocking drain (#45595), the job stays in-flight.
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
complete_transfers=False,
post_step_fn=capture_fence,
)
# Verify fence was populated at some point during the run.
assert len(job_block_ids) > 0, "No store job was created"
populated_fence = next((f for f in fence_snapshots if len(f) > 0), None)
assert populated_fence is not None, "Fence was never populated"
# Verify fence contained the job's non-SW block IDs.
for bid in job_block_ids:
assert bid in populated_fence, f"Block {bid} not in fence: {populated_fence}"
# Run 2: block reuse triggers fence-based flush → cleanup.
runner.scheduler.reset_prefix_cache()
runner.new_request(token_ids=[0] * offloaded_block_size)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
expected_stored=(0,),
expected_flushed=(0,),
)
# Verify fence is empty after full lifecycle (cleanup happened).
assert runner.connector_scheduler._block_id_to_pending_jobs == {}
# req_status should be removed.
req_id = str(runner.req_id)
assert req_id not in runner.connector_scheduler._req_status
def test_multiple_in_flight_stores_all_flushed_by_fence(request_runner):
"""When a request finishes with multiple in-flight store jobs,
ALL jobs are flushed when a new request reuses their blocks.
Uses three runner.run() calls:
- Run 1: decode fills a block → job_0 created
- Run 2: decode fills another block + EOS → job_1 created, request finishes
- Run 3: block reuse → both jobs flushed via fence
"""
block_size = 4
block_size_factor = 1
offloaded_block_size = block_size * block_size_factor
# 4 GPU blocks: block 0 is null, blocks 1-3 are usable.
runner = request_runner(
block_size=block_size,
num_gpu_blocks=4,
async_scheduling=False,
block_size_factor=block_size_factor,
)
# Prompt: 4 tokens → block 1
runner.new_request(token_ids=[0] * offloaded_block_size)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
# Run 1: 4 decoded tokens → block 2 full → job_0 created for block 1.
runner.run(
decoded_tokens=[0] * offloaded_block_size,
complete_transfers=False,
)
assert len(runner.connector_scheduler._jobs) >= 1
# Run 2: 4 more tokens + EOS → block 3 full → more jobs created.
# Request finishes → all jobs registered in fence.
runner.run(
decoded_tokens=[0] * offloaded_block_size + [EOS_TOKEN_ID],
complete_transfers=False,
)
num_jobs = len(runner.connector_scheduler._jobs)
assert num_jobs >= 2, f"Expected multiple in-flight jobs, got {num_jobs}"
# Run 3: block reuse → fence flushes both jobs.
runner.scheduler.reset_prefix_cache()
runner.new_request(token_ids=[0] * offloaded_block_size * 3)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
expected_stored=(0, 1, 2),
expected_flushed=(0, 1, 2),
)
# Post-condition: fence cleaned up, all jobs gone.
assert runner.connector_scheduler._block_id_to_pending_jobs == {}
assert len(runner.connector_scheduler._jobs) == 0
def test_request_finished_mixed_full_attn_and_sliding_window(
request_runner,
):
"""With both FullAttention and SlidingWindow groups, a single store job
has both non_sliding_window_block_ids and sliding_window_block_ids.
request_finished only registers non-SW blocks in the fence.
SW blocks were already registered at store creation time.
"""
block_size = 4
sliding_window = 8 # 2 blocks
kv_cache_groups = [
KVCacheGroupSpec(
["layer0"],
FullAttentionSpec(
block_size=block_size,
num_kv_heads=1,
head_size=1,
dtype=torch.float32,
),
),
KVCacheGroupSpec(
["layer1"],
SlidingWindowSpec(
block_size=block_size,
num_kv_heads=1,
head_size=1,
dtype=torch.float32,
sliding_window=sliding_window,
),
),
]
# Use 4 GPU blocks (2 per group) so run 2 reuses the same blocks,
# triggering a fence-based flush.
runner = request_runner(
block_size=block_size,
num_gpu_blocks=4,
async_scheduling=False,
kv_cache_groups=kv_cache_groups,
)
# 1 block of prompt (4 tokens) — 1 block per group.
runner.new_request(token_ids=[0] * block_size)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
# Capture fence state and job block IDs at each step.
fence_snapshots: list[dict] = []
sw_block_ids: set[int] = set()
non_sw_block_ids: set[int] = set()
def capture_fence():
fence_snapshots.append(
dict(runner.connector_scheduler._block_id_to_pending_jobs)
)
for js in runner.connector_scheduler._jobs.values():
if js.is_store:
sw_block_ids.update(js.sliding_window_block_ids or [])
non_sw_block_ids.update(js.non_sliding_window_block_ids or [])
# Run 1: create store job, finish request, populate fence.
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
complete_transfers=False,
post_step_fn=capture_fence,
)
# Verify job had both SW and non-SW blocks.
assert len(sw_block_ids) > 0, "No SW blocks in store job"
assert len(non_sw_block_ids) > 0, "No non-SW blocks in store job"
# Find the fence snapshot where both SW and non-SW blocks were present.
# SW blocks should appear at creation time, non-SW at request_finished.
populated_fence = None
for fence in fence_snapshots:
has_sw = all(bid in fence for bid in sw_block_ids)
has_non_sw = all(bid in fence for bid in non_sw_block_ids)
if has_sw and has_non_sw:
populated_fence = fence
break
assert populated_fence is not None, (
f"Fence never contained both SW {sw_block_ids} and "
f"non-SW {non_sw_block_ids} blocks. Snapshots: {fence_snapshots}"
)
# Run 2: block reuse triggers fence-based flush of the old job.
runner.scheduler.reset_prefix_cache()
runner.new_request(token_ids=[0] * block_size)
runner.manager.prepare_store.side_effect = lambda keys, req_context: (
generate_store_output(keys)
)
runner.run(
decoded_tokens=[EOS_TOKEN_ID],
expected_stored=((0, 0), (1, 0)),
expected_flushed=((1, 0),),
)
# Verify fence is empty after full lifecycle (cleanup happened).
assert runner.connector_scheduler._block_id_to_pending_jobs == {}
assert len(runner.connector_scheduler._jobs) == 0
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from collections.abc import Iterable, Iterator
from collections.abc import Callable, Iterable, Iterator
from dataclasses import dataclass
from typing import Any
from unittest.mock import MagicMock
@@ -430,7 +430,12 @@ class RequestRunner:
for block_idx, block in enumerate(blocks):
self.gpu_blocks[block.block_id] = GPUBlock(group_idx, block_idx)
def _run(self, decoded_tokens: list[int], complete_transfers: bool):
def _run(
self,
decoded_tokens: list[int],
complete_transfers: bool,
post_step_fn: Callable[[], None] | None = None,
):
"""
Runs multiple engine (scheduler + worker) steps.
Assumes a single request is running.
@@ -438,6 +443,8 @@ class RequestRunner:
Args:
decoded_tokens: the tokens to yield at each step.
complete_transfers: complete transfers immediately
post_step_fn: optional callback invoked after each step's
update_from_output(), before the next schedule().
"""
tokens_iter = iter(decoded_tokens)
@@ -500,6 +507,9 @@ class RequestRunner:
else:
self.scheduler.update_from_output(scheduler_output, model_runner_output)
if post_step_fn is not None:
post_step_fn()
if (
prev_token_id == EOS_TOKEN_ID
and prev_token_id != token_id
@@ -545,6 +555,7 @@ class RequestRunner:
expected_stored: tuple[int | tuple[int, int], ...] = (),
expected_loaded: tuple[int | tuple[int, int], ...] = (),
expected_flushed: tuple[int | tuple[int, int], ...] = (),
post_step_fn: Callable[[], None] | None = None,
):
"""
Runs multiple engine (scheduler + worker) steps.
@@ -570,7 +581,7 @@ class RequestRunner:
expected_flushed_gpu_blocks = self._to_gpu_blocks(expected_flushed)
self.manager.reset_mock()
self._run(decoded_tokens, complete_transfers)
self._run(decoded_tokens, complete_transfers, post_step_fn=post_step_fn)
loaded_gpu_blocks: set[GPUBlock] = set()
for transfer in self.completed_loads: