llama-stack/llama_toolchain/inference/model_parallel.py
2024-07-23 08:32:33 -07:00

104 lines
3.1 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
from copy import deepcopy
from dataclasses import dataclass
from functools import partial
from typing import Generator, List, Optional
from llama_models.llama3_1.api.chat_format import ChatFormat
from llama_models.llama3_1.api.datatypes import Message
from llama_models.llama3_1.api.tokenizer import Tokenizer
from .api.config import InlineImplConfig
from .generation import Llama
from .parallel_utils import ModelParallelProcessGroup
@dataclass
class InferenceArgs:
messages: List[Message]
temperature: float
top_p: float
max_gen_len: int
logprobs: bool
class ModelRunner:
def __init__(self, llama):
self.llama = llama
# the `task` object is the same that is sent to `ModelParallelProcessGroup.run_inference()`
def __call__(self, task: InferenceArgs):
return self.llama.chat_completion(
task.messages,
task.temperature,
task.top_p,
task.max_gen_len,
task.logprobs,
)
def init_model_cb(config: InlineImplConfig):
llama = Llama.build(config)
return ModelRunner(llama)
class LlamaModelParallelGenerator:
"""
This abstraction exists so
- we can run model parallel code without needing to run the CLIs via torchrun
- this also enables use model parallel code within a notebook context.
A Context Manager is used to ensure that the model parallel process is started and stopped
correctly. This does make the ergonomics a little awkward, because it isn't immediately
clear at the callsite why we need to use a context manager.
"""
def __init__(self, config: InlineImplConfig):
self.config = config
# this is a hack because Agent's loop uses this to tokenize and check if input is too long
# while the tool-use loop is going
checkpoint = self.config.checkpoint_config.checkpoint
self.formatter = ChatFormat(Tokenizer(checkpoint.tokenizer_path))
def start(self):
self.__enter__()
def stop(self):
self.__exit__(None, None, None)
def __enter__(self):
checkpoint = self.config.checkpoint_config.checkpoint
self.group = ModelParallelProcessGroup(
checkpoint.model_parallel_size,
init_model_cb=partial(init_model_cb, self.config),
)
self.group.start()
return self
def __exit__(self, exc_type, exc_value, exc_traceback):
self.group.stop()
def chat_completion(
self,
messages: List[Message],
temperature: float = 0.6,
top_p: float = 0.9,
max_gen_len: Optional[int] = None,
logprobs: bool = False,
) -> Generator:
req_obj = InferenceArgs(
messages=deepcopy(messages),
temperature=temperature,
top_p=top_p,
max_gen_len=max_gen_len,
logprobs=logprobs,
)
gen = self.group.run_inference(req_obj)
yield from gen