JAX-based TPU worker

This commit is contained in:
Woosuk Kwon 2024-04-16 17:37:11 +00:00
parent 6d62e4c6aa
commit 91b47e3f2f

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@ -1,18 +1,28 @@
"""A TPU worker class."""
from typing import Dict, List, Optional, Set, Tuple
from typing import Dict, List, Optional, Tuple
import jax.numpy as jnp
import torch
import torch_xla.core.xla_model as xm
from vllm.attention import get_attn_backend
from vllm.config import (CacheConfig, DeviceConfig, LoRAConfig, ModelConfig,
ParallelConfig, SchedulerConfig, VisionLanguageConfig)
from vllm.logger import init_logger
from vllm.model_executor import set_random_seed
from vllm.sequence import SamplerOutput, SequenceGroupMetadata
from vllm.utils import STR_DTYPE_TO_TORCH_DTYPE, get_dtype_size
from vllm.worker.tpu_model_runner import TPUModelRunner
from vllm.worker.worker_base import LoraNotSupportedWorkerBase
from vllm.utils import get_dtype_size, STR_DTYPE_TO_TORCH_DTYPE
logger = init_logger(__name__)
class TPUWorker:
class TPUWorker(LoraNotSupportedWorkerBase):
"""A worker class that executes (a partition of) the model on a CPU socket.
Each worker is associated with a single CPU socket. The worker is
responsible for maintaining the KV cache and executing the model on the
CPU. In case of distributed inference, each worker is assigned a partition
of the model.
"""
def __init__(
self,
@ -20,60 +30,74 @@ class TPUWorker:
parallel_config: ParallelConfig,
scheduler_config: SchedulerConfig,
device_config: DeviceConfig,
local_rank: int,
rank: int,
distributed_init_method: str,
lora_config: Optional[LoRAConfig] = None,
vision_language_config: Optional[VisionLanguageConfig] = None,
kv_cache_dtype: Optional[str] = "auto",
is_driver_worker: bool = False,
cache_config: CacheConfig,
vision_language_config: Optional[VisionLanguageConfig],
) -> None:
self.model_config = model_config
self.parallel_config = parallel_config
self.scheduler_config = scheduler_config
self.device_config = device_config
self.local_rank = local_rank
self.rank = rank
self.distributed_init_method = distributed_init_method
self.lora_config = lora_config
self.is_driver_worker = is_driver_worker
if self.is_driver_worker:
assert self.rank == 0, "The driver worker must have rank 0."
self.cache_config = cache_config
self.vision_language_config = vision_language_config
if self.vision_language_config:
assert not self.lora_config, (
"To be tested: vision language model with LoRA settings.")
assert self.device_config.device_type == "tpu"
self.device_config.device = xm.xla_device()
self.device = self.device_config.device
if self.cache_config.cache_dtype == "auto":
self.cache_dtype = self.model_config.dtype
else:
self.cache_dtype = STR_DTYPE_TO_TORCH_DTYPE[
self.cache_config.cache_dtype]
self.model_runner = TPUModelRunner(
model_config,
parallel_config,
scheduler_config,
device_config,
lora_config=self.lora_config,
kv_cache_dtype=kv_cache_dtype,
is_driver_worker=is_driver_worker,
vision_language_config=vision_language_config)
self.cache_config = None
self.tpu_cache = None
def init_device(self) -> None:
# Set random seed.
self._set_random_seed(self.model_config.seed)
set_random_seed(self.model_config.seed)
# TODO: JAX
def load_model(self):
self.model_runner.load_model()
def warm_up_model(self) -> None:
# Reset the seed to ensure that the random state is not affected by
# the model initialization and profiling.
self._set_random_seed(self.model_config.seed)
def determine_num_available_blocks(self) -> Tuple[int, int]:
num_tpu_blocks = 100
return num_tpu_blocks, 0
def initialize_cache(
self,
num_gpu_blocks: int,
num_cpu_blocks: int,
) -> None:
self.cache_config.num_gpu_blocks = num_gpu_blocks
self.cache_config.num_cpu_blocks = num_cpu_blocks
self.block_size = self.cache_config.block_size
dtype = _torch_dtype_to_jax(self.cache_dtype)
num_layers = self.model_config.get_num_layers(self.parallel_config)
num_kv_heads = self.model_config.get_num_kv_heads(self.parallel_config)
head_size = self.model_config.get_head_size()
self.tpu_cache = [
jnp.zeros(
(2, num_kv_heads, num_gpu_blocks, self.block_size, head_size),
dtype=dtype) for _ in range(num_layers)
]
self.model_runner.block_size = self.block_size
def get_cache_block_size_bytes(self) -> int:
head_size = self.model_config.get_head_size()
num_heads = self.model_config.get_num_kv_heads(self.parallel_config)
num_layers = self.model_config.get_num_layers(self.parallel_config)
key_cache_block = self.cache_config.block_size * num_heads * head_size
value_cache_block = key_cache_block
total = num_layers * (key_cache_block + value_cache_block)
dtype_size = get_dtype_size(self.cache_dtype)
return dtype_size * total
@torch.inference_mode()
def execute_model(
self,
seq_group_metadata_list: Optional[List[SequenceGroupMetadata]] = None,
@ -101,84 +125,11 @@ class TPUWorker:
self.tpu_cache)
return output
def allocate_kv_cache(self, cache_config: CacheConfig) -> None:
self.cache_config = cache_config
kv_cache_shape = self.attn_backend.get_kv_cache_shape(
cache_config.num_gpu_blocks, cache_config.block_size, self.num_heads, self.head_size)
kv_cache: List[torch.Tensor] = []
for _ in range(self.num_layers):
kv_cache.append(
torch.empty(kv_cache_shape,
dtype=self.dtype,
device=self.device))
self.tpu_cache = kv_cache
def _set_random_seed(self, seed: int) -> None:
xm.set_rng_state(seed, device=self.device)
set_random_seed(seed)
class CacheEngine:
def __init__(
self,
cache_config: CacheConfig,
model_config: ModelConfig,
parallel_config: ParallelConfig,
device_config: DeviceConfig,
) -> None:
self.cache_config = cache_config
self.model_config = model_config
self.parallel_config = parallel_config
self.device_config = device_config
self.head_size = model_config.get_head_size()
self.num_layers = model_config.get_num_layers(parallel_config)
self.num_heads = model_config.get_num_kv_heads(parallel_config)
self.block_size = cache_config.block_size
self.num_tpu_blocks = cache_config.num_gpu_blocks
if cache_config.cache_dtype == "auto":
self.dtype = model_config.dtype
else:
self.dtype = STR_DTYPE_TO_TORCH_DTYPE[cache_config.cache_dtype]
self.device = device_config.device
# Get attention backend.
self.attn_backend = get_attn_backend(self.dtype)
# Initialize the cache.
kv_cache_shape = self.attn_backend.get_kv_cache_shape(
self.num_tpu_blocks, self.block_size, self.num_heads, self.head_size)
self.tpu_cache: List[torch.Tensor] = []
for _ in range(self.num_layers):
self.tpu_cache.append(
torch.empty(kv_cache_shape,
dtype=self.dtype,
device=self.device))
def copy(self, src_to_dsts: Dict[int, List[int]]) -> None:
raise NotImplementedError(
"Copying blocks is not supported on TPU backend.")
@staticmethod
def get_cache_block_size(
block_size: int,
cache_dtype: str,
model_config: ModelConfig,
parallel_config: ParallelConfig,
) -> int:
head_size = model_config.get_head_size()
num_heads = model_config.get_num_kv_heads(parallel_config)
num_layers = model_config.get_num_layers(parallel_config)
key_cache_block = block_size * num_heads * head_size
value_cache_block = key_cache_block
total = num_layers * (key_cache_block + value_cache_block)
if cache_dtype == "auto":
dtype = model_config.dtype
else:
dtype = STR_DTYPE_TO_TORCH_DTYPE[cache_dtype]
dtype_size = get_dtype_size(dtype)
return dtype_size * total
def _torch_dtype_to_jax(dtype: torch.dtype) -> jnp.dtype:
mapping = {
torch.float32: jnp.float32,
torch.float16: jnp.float16,
torch.bfloat16: jnp.bfloat16,
}
return mapping[dtype]