vllm/tests/v1/tpu/worker/test_tpu_model_runner.py
Yong Hoon Shin bdf13965ab
[V1] Support cross-layer KV sharing (#18212)
Signed-off-by: Yong Hoon Shin <yhshin@meta.com>
2025-06-03 20:33:07 +00:00

591 lines
20 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import unittest.mock as mock
import pytest
from vllm.attention.layer import Attention
from vllm.config import (CacheConfig, ModelConfig, SchedulerConfig, VllmConfig,
set_current_vllm_config)
from vllm.sampling_params import SamplingParams
from vllm.utils import GiB_bytes
from vllm.v1.core.kv_cache_utils import (estimate_max_model_len,
get_kv_cache_config)
from vllm.v1.core.sched.output import (CachedRequestData, NewRequestData,
SchedulerOutput)
from vllm.v1.worker.tpu_model_runner import (
TPUModelRunner, _get_padded_num_reqs_with_upper_limit,
_get_padded_token_len, _get_req_paddings, _get_token_paddings)
# Mock torch_xla module since it may not be available in the test environments
torch_xla_patcher = mock.patch.dict(
"sys.modules", {
"torch_xla": mock.MagicMock(),
"torch_xla.core.xla_model": mock.MagicMock(),
"torch_xla.runtime": mock.MagicMock(),
})
torch_xla_patcher.start()
# Mock the PallasAttentionBackend
pallas_attention_backend_patcher = mock.patch(
"vllm.v1.worker.tpu_model_runner.PallasAttentionBackend", )
pallas_attention_backend_patcher.start()
@pytest.fixture
def model_runner():
# Patchers have already been started at module level.
scheduler_config = SchedulerConfig(
max_num_seqs=10,
max_num_batched_tokens=512,
max_model_len=512,
)
model_config = ModelConfig(
model="facebook/opt-125m",
task="generate",
tokenizer="facebook/opt-125m",
tokenizer_mode="auto",
trust_remote_code=True,
dtype="bfloat16", # TPUs typically use bfloat16
seed=42,
)
cache_config = CacheConfig(
block_size=16,
gpu_memory_utilization=0.9,
swap_space=0,
cache_dtype="auto",
)
vllm_config = VllmConfig(
model_config=model_config,
cache_config=cache_config,
scheduler_config=scheduler_config,
)
device = "xla:0" # Mocking TPU device
with mock.patch("vllm.v1.worker.tpu_model_runner.torch"), \
mock.patch("vllm.v1.worker.tpu_model_runner.xm"), \
mock.patch("vllm.v1.worker.tpu_model_runner.xr"):
return TPUModelRunner(vllm_config, device)
@pytest.fixture(autouse=True, scope="session")
def cleanup_patches():
yield
torch_xla_patcher.stop()
pallas_attention_backend_patcher.stop()
def _schedule_new_request(*req_ids: str) -> SchedulerOutput:
new_reqs = []
num_scheduled_tokens = {}
total_num_scheduled_tokens = 0
for req_id in req_ids:
new_reqs.append(
NewRequestData(
req_id=req_id,
prompt_token_ids=[1, 2, 3],
mm_inputs=[],
mm_hashes=[],
mm_positions=[],
sampling_params=SamplingParams(),
block_ids=[[0]], # block_ids should be list[list[int]]
num_computed_tokens=0,
lora_request=None,
))
num_scheduled_tokens[req_id] = 3
total_num_scheduled_tokens += num_scheduled_tokens[req_id]
return SchedulerOutput(
scheduled_new_reqs=new_reqs,
scheduled_cached_reqs=[],
num_scheduled_tokens=num_scheduled_tokens,
total_num_scheduled_tokens=total_num_scheduled_tokens,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
def _is_req_scheduled(model_runner, req_id: str) -> bool:
return req_id in model_runner.input_batch.req_id_to_index
def _is_req_added(model_runner, req_id: str) -> bool:
return req_id in model_runner.requests
def _is_req_state_block_table_match(model_runner, req_id: str) -> bool:
"""Check if the request state block IDs match the block table.
This function handles both legacy BlockTable and new MultiGroupBlockTable
structures for backward compatibility.
"""
req_index = model_runner.input_batch.req_id_to_index[req_id]
multi_group_block_table = model_runner.input_batch.block_table
req_state = model_runner.requests[req_id]
# Access the first block table from MultiGroupBlockTable
# This is safe since we currently only use single KV cache groups
block_table = multi_group_block_table[0]
# req_state.block_ids is now list[list[int]] for MultiGroupBlockTable
# Extract the first group's block IDs
if isinstance(req_state.block_ids[0], list):
# New format: list[list[int]] - extract first group
req_block_ids = req_state.block_ids[0]
else:
# Legacy format: list[int] - use directly
req_block_ids = req_state.block_ids
if block_table.num_blocks_per_row[req_index] != len(req_block_ids):
return False
num_blocks = block_table.num_blocks_per_row[req_index]
block_table_values = block_table.block_table_np[req_index, :num_blocks]
return (block_table_values == req_block_ids).all()
def test_update_states_new_request(model_runner):
req_id = "req_0"
# new req
scheduler_output = _schedule_new_request(req_id)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
assert _is_req_state_block_table_match(model_runner, req_id)
def test_update_states_request_finished(model_runner):
req_id = "req_0"
# new req
scheduler_output = _schedule_new_request(req_id)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
# finish req
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={},
total_num_scheduled_tokens=0,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids={req_id},
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
model_runner._update_states(scheduler_output)
assert not _is_req_added(model_runner, req_id)
assert not _is_req_scheduled(model_runner, req_id)
def test_update_states_request_resumed(model_runner):
req_id = "req_0"
# new req
scheduler_output = _schedule_new_request(req_id)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
# unschedule req
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={},
total_num_scheduled_tokens=0,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert not _is_req_scheduled(model_runner, req_id)
# resume req
cached_req_data = CachedRequestData(
req_id=req_id,
resumed_from_preemption=False,
new_token_ids=[],
new_block_ids=[],
num_computed_tokens=0,
)
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[cached_req_data],
num_scheduled_tokens={req_id: 1},
total_num_scheduled_tokens=1,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
assert _is_req_state_block_table_match(model_runner, req_id)
def test_update_states_no_changes(model_runner):
req_id = "req_0"
# new req
scheduler_output = _schedule_new_request(req_id)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
# schedule req
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={req_id: 1},
total_num_scheduled_tokens=1,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_id)
assert _is_req_scheduled(model_runner, req_id)
assert _is_req_state_block_table_match(model_runner, req_id)
def test_update_states_request_unscheduled(model_runner):
req_ids = ("req_0", "req_1")
# new reqs
scheduler_output = _schedule_new_request(*req_ids)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_ids[0])
assert _is_req_scheduled(model_runner, req_ids[0])
assert _is_req_added(model_runner, req_ids[1])
assert _is_req_scheduled(model_runner, req_ids[1])
# unschedule req_1
scheduler_output = SchedulerOutput(
scheduled_new_reqs=[],
scheduled_cached_reqs=[],
num_scheduled_tokens={req_ids[0]: 1},
total_num_scheduled_tokens=1,
scheduled_spec_decode_tokens={},
scheduled_encoder_inputs={},
num_common_prefix_blocks=0,
finished_req_ids=set(),
free_encoder_input_ids=[],
structured_output_request_ids={},
grammar_bitmask=None,
)
model_runner._update_states(scheduler_output)
assert _is_req_added(model_runner, req_ids[0])
assert _is_req_scheduled(model_runner, req_ids[0])
assert _is_req_added(model_runner, req_ids[1])
assert not _is_req_scheduled(model_runner, req_ids[1])
def test_get_paddings():
# Bucketed padding
min_token_size, max_token_size, padding_gap = 16, 512, 64
expected_paddings = [16, 32, 64, 128, 192, 256, 320, 384, 448, 512]
actual_paddings = _get_token_paddings(min_token_size, max_token_size,
padding_gap)
# Bucketed padding with max_token_size not a power of two.
max_token_size = 317
expected_paddings = [16, 32, 64, 128, 192, 256, 320]
actual_paddings = _get_token_paddings(min_token_size, max_token_size,
padding_gap)
assert actual_paddings == expected_paddings
# Exponential padding.
max_token_size, padding_gap = 1024, 0
expected_paddings = [16, 32, 64, 128, 256, 512, 1024]
actual_paddings = _get_token_paddings(min_token_size, max_token_size,
padding_gap)
assert actual_paddings == expected_paddings
# Exponential padding with max_token_size not a power of two.
max_token_size = 317
expected_paddings = [16, 32, 64, 128, 256, 512]
actual_paddings = _get_token_paddings(min_token_size, max_token_size,
padding_gap)
assert actual_paddings == expected_paddings
def test_get_padded_token_len():
min_token_size, max_token_size, padding_gap = 16, 512, 64
paddings = _get_token_paddings(min_token_size, max_token_size, padding_gap)
assert _get_padded_token_len(paddings, 1) == 16
assert _get_padded_token_len(paddings, 16) == 16
assert _get_padded_token_len(paddings, 20) == 32
assert _get_padded_token_len(paddings, 300) == 320
assert _get_padded_token_len(paddings, 512) == 512
def test_get_padded_num_reqs_with_upper_limit():
assert _get_padded_num_reqs_with_upper_limit(3, 32) == 8
assert _get_padded_num_reqs_with_upper_limit(9, 32) == 16
assert _get_padded_num_reqs_with_upper_limit(19, 32) == 32
assert _get_padded_num_reqs_with_upper_limit(17, 28) == 28
def test_get_req_paddings():
assert _get_req_paddings(1, 32) == [8, 16, 32]
assert _get_req_paddings(8, 32) == [8, 16, 32]
assert _get_req_paddings(8, 36) == [8, 16, 32, 36]
def test_init_kv_cache_with_kv_sharing_invalid_target_layer_order():
layer_0 = "model.layers.0.self_attn.attn"
layer_1 = "model.layers.1.self_attn.attn"
error_msg = f"{layer_1} must come before the current layer"
with pytest.raises(ValueError, match=error_msg):
fwd_context = {
# initialization below will fail because target layer is invalid;
# the target layer needs to come before layer 1
layer_0:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_0,
kv_sharing_target_layer_name=layer_1,
),
layer_1:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_1,
)
}
# suppress var not used error
assert fwd_context is not None
def test_init_kv_cache_with_kv_sharing_target_layer_not_exist():
layer_0 = "model.layers.0.self_attn.attn"
layer_1 = "model.layers.1.self_attn.attn"
invalid_layer = "model.layers.0.cross_attn.attn"
error_msg = f"{invalid_layer} is not a valid Attention layer in the model"
with pytest.raises(ValueError, match=error_msg):
fwd_context = {
layer_0:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_0,
),
layer_1:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_1,
# invalid layer: cross_attn.atn doesn't exist!
kv_sharing_target_layer_name=invalid_layer,
)
}
# suppress var not used error
assert fwd_context is not None
def test_init_kv_cache_with_kv_sharing_target_same_as_current():
layer_0 = "model.layers.0.self_attn.attn"
layer_1 = "model.layers.1.self_attn.attn"
error_msg = f"{layer_1} cannot be the same as the current layer"
with pytest.raises(ValueError, match=error_msg):
fwd_context = {
# initialization below will fail because target layer is invalid;
# the target layer needs to come before layer 1
layer_0:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_0,
),
layer_1:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_1,
kv_sharing_target_layer_name=layer_1,
)
}
# suppress var not used error
assert fwd_context is not None
def test_init_kv_cache_without_kv_sharing(model_runner):
layer_0 = "model.layers.0.self_attn.attn"
layer_1 = "model.layers.1.self_attn.attn"
vllm_config = model_runner.vllm_config
with set_current_vllm_config(vllm_config):
fwd_context = {
layer_0:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_0,
),
layer_1:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_1,
)
}
# suppress var not used error
assert fwd_context is not None
# Set high context length to test max context length estimation
vllm_config.model_config.max_model_len = 3_000_000
vllm_ctx = vllm_config.compilation_config.static_forward_context
kv_cache_spec = model_runner.get_kv_cache_spec()
assert len(kv_cache_spec) == 2
assert len(model_runner.shared_kv_cache_layers) == 0
available_memory = 20 * GiB_bytes
# page size for layer 0's kv_cache_spec is 32KB
num_expected_blocks = 327680 # 20GB / 32KB / 2 (num layers)
kv_cache_config = get_kv_cache_config(vllm_config, kv_cache_spec,
available_memory)
assert kv_cache_config.num_blocks == num_expected_blocks
assert len(kv_cache_config.tensors) == 2
assert kv_cache_config.tensors[layer_0].size == available_memory // 2
assert kv_cache_config.tensors[layer_1].size == available_memory // 2
max_context_len =\
estimate_max_model_len(vllm_config, kv_cache_spec, 5 * GiB_bytes)
# max context len with KV sharing should be 2x as large as without
assert max_context_len == 1310720
# important: override tensor size to prevent large mem alloc during test
# this will only allocate 2 block worth of memory (2 * 32kb)
kv_cache_config.num_blocks = 1
for layer in kv_cache_config.tensors:
kv_cache_config.tensors[layer].size =\
kv_cache_spec[layer].page_size_bytes
model_runner.initialize_kv_cache(kv_cache_config)
layer_0_kv = vllm_ctx[layer_0].kv_cache[0]
layer_1_kv = vllm_ctx[layer_1].kv_cache[0]
# check layer 1 kv cache does NOT share memory with layer 0
assert id(layer_1_kv) != id(layer_0_kv)
# check layer 1 added to kv cache group's layer names
assert len(kv_cache_config.kv_cache_groups) == 1
assert len(kv_cache_config.kv_cache_groups[0].layer_names) == 2
assert kv_cache_config.kv_cache_groups[0].layer_names[0] == layer_0
assert kv_cache_config.kv_cache_groups[0].layer_names[1] == layer_1
def test_init_kv_cache_with_kv_sharing_valid(model_runner):
layer_0 = "model.layers.0.self_attn.attn"
layer_1 = "model.layers.1.self_attn.attn"
vllm_config = model_runner.vllm_config
with set_current_vllm_config(vllm_config):
fwd_context = {
layer_0:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_0,
),
layer_1:
Attention(
num_heads=8,
head_size=64,
scale=1.0,
prefix=layer_1,
kv_sharing_target_layer_name="model.layers.0.self_attn.attn",
)
}
# suppress var not used error
assert fwd_context is not None
# Set high context length to test max context length estimation
vllm_config.model_config.max_model_len = 3_000_000
vllm_ctx = vllm_config.compilation_config.static_forward_context
kv_cache_spec = model_runner.get_kv_cache_spec()
assert len(kv_cache_spec) == 1
assert layer_0 in kv_cache_spec
assert model_runner.shared_kv_cache_layers[layer_1] == layer_0
available_memory = 20 * GiB_bytes
# page size for layer 0's kv_cache_spec is 32KB
# with KV sharing, we can allocate (available_mem//page_size//1) blocks
# which is twice as many as without KV sharing
num_expected_blocks = 655360 # 20GB / 32KB
kv_cache_config = get_kv_cache_config(vllm_config, kv_cache_spec,
available_memory)
assert kv_cache_config.num_blocks == num_expected_blocks
assert len(kv_cache_config.tensors) == 1
# Each layer now has twice the available memory for KV cache
# compared to no KV sharing
assert kv_cache_config.tensors[layer_0].size == available_memory
max_context_len =\
estimate_max_model_len(vllm_config, kv_cache_spec, 5 * GiB_bytes)
# max context len with KV sharing should be 2x as large as without
assert max_context_len == 2 * 1310720
# important: override tensor size to prevent large mem alloc during test
# this will only allocate 1 block worth of memory (32kb)
kv_cache_config.num_blocks = 1
kv_cache_config.tensors[layer_0].size =\
kv_cache_spec[layer_0].page_size_bytes
model_runner.initialize_kv_cache(kv_cache_config)
layer_0_kv = vllm_ctx[layer_0].kv_cache[0]
layer_1_kv = vllm_ctx[layer_1].kv_cache[0]
# check layer 1 kv cache shares memory with layer 0
assert id(layer_1_kv) == id(layer_0_kv)
# check layer 1 added to kv cache group's layer names
assert len(kv_cache_config.kv_cache_groups) == 1
assert len(kv_cache_config.kv_cache_groups[0].layer_names) == 2
assert kv_cache_config.kv_cache_groups[0].layer_names[0] == layer_0
assert kv_cache_config.kv_cache_groups[0].layer_names[1] == layer_1