ColossalAI/colossalai/pipeline/rpc/_pipeline_base.py

852 lines
35 KiB
Python

import threading
from enum import Enum
from typing import List, Any, Tuple, Dict, Callable
from abc import ABC, abstractmethod
import sys
import os
import torch
from torch import nn
import torch.distributed.rpc as rpc
from torch.futures import Future
from torch._C._distributed_rpc import PyRRef
from torch import autograd
from torch import optim
from tqdm import tqdm
from time import time
from colorama import Back, Style
# config for debug and test
use_color_debug = True
# TODO:
# 1. adjust to args and kwargs (pytree)
def color_debug(text, prefix=' ', color='blue'):
if use_color_debug:
color = color.upper()
print(getattr(Back, color), prefix, Style.RESET_ALL, text)
def tensor_shape_list(tensors):
if tensors is None:
return None
if isinstance(tensors, (int, float)):
return tensors
if isinstance(tensors, torch.Tensor):
return tensors.shape
shapes = []
for t in tensors:
if hasattr(t, 'shape'):
shapes.append(t.shape)
else:
shapes.append('non tensor')
return shapes
def get_real_args(args):
if isinstance(args, torch.Tensor):
return args
elif isinstance(args, list):
real_args = []
for arg in args:
if isinstance(arg, Future):
value = arg.wait()
else:
value = arg
if isinstance(value, list):
real_args.extend(value)
else:
real_args.append(value)
return real_args
else:
raise TypeError(f"Expect receive tensor or list, but receive {type(args)}")
class Phase(Enum):
FORWARD = 0
BACKWARD = 1
UPDATE = 2
class UniqueKey:
__slots__ = ('microbatch_id', 'phase')
microbatch_id: int
phase: Phase
def __init__(self, microbatch_id, phase) -> None:
self.microbatch_id = microbatch_id
self.phase = phase
def __eq__(self, __o: object) -> bool:
return (self.microbatch_id == __o.microbatch_id) and (self.phase == __o.phase)
def __hash__(self) -> int:
return tuple.__hash__((self.microbatch_id, self.phase))
def __repr__(self) -> str:
return f'Key(microbatch_id={self.microbatch_id}, phase={self.phase})'
class WorkItem:
__slots__ = ('stage_id', 'phase', 'args', 'kwargs', 'output', 'refcount', 'microbatch_id', 'batch_id',
'num_microbatches', 'forward_only')
stage_id: int
phase: Phase
args: Tuple[Any]
kwargs: Dict[str, Any]
output: Future
microbatch_id: int
refcount: int
batch_id: int
num_microbatches: int
forward_only: bool
def __init__(self,
stage_id,
phase,
args,
kwargs,
output,
microbatch_id,
batch_id,
num_microbatches,
forward_only,
refcount=0) -> None:
for attr_name in self.__slots__:
setattr(self, attr_name, locals()[attr_name])
class BackwardCache:
__slots__ = ('checkpoint', 'stage_inputs', 'stage_outputs')
checkpoint: bool
stage_inputs: Tuple[Any]
stage_outputs: Tuple[Any]
def __init__(self,
stage_inputs: List[torch.Tensor],
stage_outputs: List[torch.Tensor] = None,
checkpoint: bool = False) -> None:
for arg_name in self.__slots__:
setattr(self, arg_name, locals()[arg_name])
class WorkerBase(ABC):
def __init__(self,
partition_fn: Callable,
partition_args: tuple,
pp_rank: int,
actual_stage_num: int,
num_microbatches: int,
device: str,
criterion: Callable = None,
metric: Callable = None,
checkpoint: bool = False) -> None:
super().__init__()
self.pp_rank = pp_rank
self.actual_stage_num = actual_stage_num
self.num_microbatches = num_microbatches
self.checkpoint = checkpoint
self.device = device
self._initialize_outstanding_range()
# variable and const for context managment
self.outstanding = 0
self.forward_times = 0
self.backward_times = 0
self.reset_key = UniqueKey(0, Phase.FORWARD)
# rref of other workers
self.pp_rank_to_worker_rref: Dict[int, PyRRef] = None
# lock for the list
self._initialize_lock()
# topology info
self.producer_stage_ids: List[int] = None
self.consumer_stage_ids: List[int] = None
# module partitions
self.partition_fn = partition_fn
self.partition_args = partition_args
self.criterion = criterion
self.metric = metric
# context to maintain loop
self._initialize_context_container()
# main loop
self.main_loop_thread = threading.Thread(target=self._work_loop, name=f'rank_{pp_rank}', daemon=True)
self.main_loop_thread.start()
def _get_future_by_device(self):
return torch.futures.Future(devices=None if self.device in (None, 'cpu') else [self.device])
def _initialize_outstanding_range(self):
outstanding_range = None
if self.pp_rank == self.actual_stage_num - 1:
outstanding_range = (0, 1)
else:
outstanding_range = (self.actual_stage_num, self.actual_stage_num)
self.outstanding_range = outstanding_range
def _initialize_context_container(self):
self.microbatch_id_to_backward_cache: Dict[int, BackwardCache] = dict()
self.microbatch_id_to_labels: Dict[int, Any] = dict()
self.work_list: Dict[UniqueKey, WorkItem] = dict()
self.output_list: Dict[UniqueKey, WorkItem] = dict()
def _initialize_lock(self):
self.partition_condition_lock = threading.Condition(threading.Lock())
self.work_list_condition_lock = threading.Condition(threading.Lock())
self.output_list_condition_lock = threading.Condition(threading.Lock())
self.label_lock = threading.Condition(threading.Lock())
def _initialize_partition(self):
partition_fn = self.partition_fn
partition_args = self.partition_args
device = self.device
with self.partition_condition_lock:
self.module_partition: nn.Module = partition_fn(*partition_args).to(device)
self.partition_condition_lock.notify_all()
def sync_global_worker_rrefs(self, pp_rank_to_worker_rref: Dict[int, PyRRef]) -> None:
assert self.pp_rank_to_worker_rref is None, f"in rank {self.pp_rank}, worker has sync global workers rrefs"
assert pp_rank_to_worker_rref is not None, "stage_to_workers must be a dict instead of None"
self.pp_rank_to_worker_rref = pp_rank_to_worker_rref
# for some schedule need the other worker's info to initialise partition (like Chimera)
# construction of partition is executed after the registion of pp_rank_to_worker_rref
self._initialize_partition()
def get_output_by_key(self, key: UniqueKey) -> Any:
with self.output_list_condition_lock:
self.output_list_condition_lock.wait_for(lambda: key in self.output_list)
output_work_item = self.output_list[key]
output = output_work_item.output
if isinstance(output, Future):
output = output.wait()
# color_debug(f'rank {self.pp_rank}, output {type(output)}', 'get output', 'red')
output_work_item.refcount += 1
# all consumers have been satisfied, the work_item can be released
with self.output_list_condition_lock:
if output_work_item.refcount >= len(self.consumer_stage_ids):
self.output_list.pop(key)
return output
def get_parameters(self) -> List[torch.Tensor]:
return [p for p in self.module_partition.parameters()]
def get_parameter_gradients(self) -> List[torch.Tensor]:
return [p.grad for p in self.module_partition.parameters()]
def get_partition(self):
with self.partition_condition_lock:
self.partition_condition_lock.wait_for(lambda: hasattr(self, 'module_partition'))
return self.module_partition
def get_partition_state_dict(self):
with self.partition_condition_lock:
self.partition_condition_lock.wait_for(lambda: hasattr(self, 'module_partition'))
return self.module_partition.state_dict()
# just for first pp_rank
def set_input(self, microbatch_id: int, microbatch: Tuple[Any], forward_only: bool):
assert self.consumer_stage_ids is not None
key = UniqueKey(microbatch_id, Phase.FORWARD)
output = self._get_future_by_device()
args = [microbatch] if isinstance(microbatch, torch.Tensor) else microbatch
work_item = WorkItem(self.pp_rank, Phase.FORWARD, args, {}, output, microbatch_id, None, self.num_microbatches,
forward_only)
with self.work_list_condition_lock:
self.work_list[key] = work_item
color_debug(f'rank {self.pp_rank} receive data from dataloader {self._get_store_len()}', 'data dispatch',
'magenta')
self.work_list_condition_lock.notify_all()
# just for last pp_rank
def set_labels(self, microbatch_id: int, microlabels: Any):
with self.label_lock:
self.microbatch_id_to_labels[microbatch_id] = microlabels
self.label_lock.notify_all()
# just for last pp_rank
def _begin_backward(self, microbatch_id: int):
with self.work_list_condition_lock:
assert self.producer_stage_ids is not None
key = UniqueKey(microbatch_id, Phase.BACKWARD)
output = self._get_future_by_device()
grad_wrt_loss = torch.tensor(1, device=self.device)
work_item = WorkItem(self.pp_rank, Phase.BACKWARD, grad_wrt_loss, {}, output, microbatch_id, None,
self.num_microbatches, False)
color_debug(f'rank {self.pp_rank} propose backward', 'data dispatch', 'magenta')
self.work_list[key] = work_item
self.work_list_condition_lock.notify_all()
def subscribe_producer(self, microbatch_id: int, forward_only: bool):
"""
You should call this function asynchronously
"""
assert self.producer_stage_ids is not None
producer_num = len(self.producer_stage_ids)
assert producer_num > 0, "only stage that has producers can subscribe producers"
stage_id = self.pp_rank
subscribe_forward_futures: List[Future] = [None] * producer_num
output = self._get_future_by_device()
for i in range(producer_num):
producer_stage_id = self.producer_stage_ids[i]
producer_output_key = UniqueKey(microbatch_id, Phase.FORWARD)
producer_worker_rref = self.pp_rank_to_worker_rref[producer_stage_id]
subscribe_forward_futures[i] = producer_worker_rref.rpc_async().get_output_by_key(producer_output_key)
color_debug(f'rank {self.pp_rank} get {len(subscribe_forward_futures)} futs from its producer', 'data dispatch',
'magenta')
work_item_from_producer = WorkItem(stage_id, Phase.FORWARD, subscribe_forward_futures, {}, output,
microbatch_id, None, self.num_microbatches, forward_only)
# color_debug(f'rank {self.pp_rank} get value {tensor_shape_list(args)} from fut', 'data dispatch', 'magenta')
# add work_item to work_list
with self.work_list_condition_lock:
key = UniqueKey(microbatch_id, Phase.FORWARD)
assert key not in self.work_list
self.work_list[key] = work_item_from_producer
color_debug(
f'rank_{self.pp_rank} load a new task to its work_list {key} {work_item_from_producer.phase} data: {tensor_shape_list(work_item_from_producer.args)}',
'data dispatch', 'magenta')
self.work_list_condition_lock.notify_all()
def subscribe_consumer(self, microbatch_id: int):
"""
You should call this function asynchronously
"""
assert self.producer_stage_ids is not None
consumer_num = len(self.consumer_stage_ids)
assert consumer_num > 0, "only stage that has consumers can subscribe comsumers"
stage_id = self.pp_rank
subscribe_backward_futures: List[Future] = [None] * consumer_num
output = self._get_future_by_device()
color_debug(f'rank {self.pp_rank} get {len(subscribe_backward_futures)} futs from its consumer',
'data dispatch', 'magenta')
for i in range(consumer_num):
consumer_stage_id = self.consumer_stage_ids[i]
consumer_output_key = UniqueKey(microbatch_id, Phase.BACKWARD)
consumer_worker_rref = self.pp_rank_to_worker_rref[consumer_stage_id]
subscribe_backward_futures[i] = consumer_worker_rref.rpc_async().get_output_by_key(consumer_output_key)
# flatten args
work_item_from_consumer = WorkItem(stage_id, Phase.BACKWARD, subscribe_backward_futures, {}, output,
microbatch_id, None, self.num_microbatches, False)
# color_debug(f'rank {self.pp_rank} get value {tensor_shape_list(args)} from fut', 'data dispatch', 'magenta')
# add work_item to work_list
with self.work_list_condition_lock:
key = UniqueKey(microbatch_id, Phase.BACKWARD)
assert key not in self.work_list
self.work_list[key] = work_item_from_consumer
color_debug(
f'rank_{self.pp_rank} load a new task to its work_list {key} {work_item_from_consumer.phase} data: {tensor_shape_list(work_item_from_consumer.args)}',
'data dispatch', 'magenta')
self.work_list_condition_lock.notify_all()
def _get_producer_consumer(self) -> None:
rank = self.pp_rank
assert self.producer_stage_ids is None, f"all the producers of rank {rank} has been subscribed"
assert self.consumer_stage_ids is None, f"all the consumers of rank {rank} has been subscribed"
# should be aranged in order, the order of the input of current forward
self.producer_stage_ids = []
self.consumer_stage_ids = []
# Just for demo
prev_rank = rank - 1
next_rank = rank + 1
if prev_rank >= 0:
self.producer_stage_ids.append(prev_rank)
if next_rank <= self.actual_stage_num - 1:
self.consumer_stage_ids.append(next_rank)
@abstractmethod
def _get_work_item_key(self) -> UniqueKey:
"""
this method control the order of the microbatch to consume
"""
def is_first_stage(self):
return self.pp_rank == 0
def is_last_stage(self):
return self.pp_rank == self.actual_stage_num - 1
def _consume_work_item_by_phase(self, work_item: WorkItem):
phase = work_item.phase
args = work_item.args
kwargs = work_item.kwargs
microbatch_id = work_item.microbatch_id
forward_only = work_item.forward_only
consume_result = None
is_first_stage = self.is_first_stage()
is_last_stage = self.is_last_stage()
# if self.pp_rank == 0:
# print(
# f'I am rank_{self.pp_rank} microbatch_id : {microbatch_id} {phase} {self._get_store_len()} | {self.outstanding} {self.outstanding_range}'
# )
if phase == Phase.FORWARD:
# remind its consumer to get data before forward
if not is_last_stage:
for stage_id in self.consumer_stage_ids:
consumer_worker_rref = self.pp_rank_to_worker_rref[stage_id]
consumer_worker_rref.remote().subscribe_producer(microbatch_id, forward_only)
self.forward_times += 1
if not forward_only:
self.outstanding += 1
args = get_real_args(args)
# last stage doesn't need to do checkpoint, for it will do backward instantly
if forward_only:
with torch.no_grad():
consume_result = self.module_partition(*args, **kwargs)
# TODO : integrate output list
if is_last_stage and self.criterion:
with self.label_lock:
self.label_lock.wait_for(lambda: microbatch_id in self.microbatch_id_to_labels)
labels = self.microbatch_id_to_labels.pop(microbatch_id)
loss: torch.Tensor = self.criterion(consume_result, labels)
if self.metric is not None:
metric_result = self.metric(consume_result, labels)
if isinstance(metric_result, torch.Tensor):
metric_result = metric_result.item()
else:
metric_result = None
consume_result = [loss.item(), metric_result]
stage_outputs = None
stage_inputs = None
use_checkpoint = None
elif self.checkpoint and not is_last_stage:
with torch.no_grad():
consume_result = self.module_partition(*args, **kwargs)
stage_outputs = None
stage_inputs = args
use_checkpoint = True
else:
consume_result = self.module_partition(*args, **kwargs)
# print(f'model{self.pp_rank + 1}(param_sum: {sum([p.sum().item() for p in self.module_partition.parameters()])}) input sum: {args[0].sum().item()} forward output sum: {consume_result.sum().item()}', )
if is_last_stage and self.criterion:
with self.label_lock:
self.label_lock.wait_for(lambda: microbatch_id in self.microbatch_id_to_labels)
labels = self.microbatch_id_to_labels.pop(microbatch_id)
loss: torch.Tensor = self.criterion(consume_result, labels)
if self.metric is not None:
metric_result = self.metric(consume_result, labels)
if isinstance(metric_result, torch.Tensor):
metric_result = metric_result.item()
else:
metric_result = None
consume_result = [loss.item(), metric_result]
else:
loss = consume_result
stage_outputs = loss
stage_inputs = args
use_checkpoint = False
if not forward_only:
self.microbatch_id_to_backward_cache[microbatch_id] = BackwardCache(stage_inputs,
stage_outputs,
checkpoint=use_checkpoint)
consume_result = [consume_result] if isinstance(consume_result,
(torch.Tensor, int, float)) else consume_result
# if not forward_only, do the backward
if not forward_only:
if is_last_stage: # if it is the last stage, trigger backward automatic
self._begin_backward(microbatch_id)
elif phase == Phase.BACKWARD:
# remind its producer to get data before backward
if not is_first_stage:
for stage_id in self.producer_stage_ids:
producer_worker_rref = self.pp_rank_to_worker_rref[stage_id]
producer_worker_rref.remote().subscribe_consumer(microbatch_id)
self.backward_times += 1
self.outstanding -= 1
assert microbatch_id in self.microbatch_id_to_backward_cache, f"microbatch_id {microbatch_id} not in backward cache"
backward_cache = self.microbatch_id_to_backward_cache.pop(microbatch_id)
stage_outputs = backward_cache.stage_outputs
stage_inputs = backward_cache.stage_inputs
use_checkpoint = backward_cache.checkpoint
if use_checkpoint:
stage_outputs = [self.module_partition(*stage_inputs)]
# overlap recompute and future.wait
grad_tensors = get_real_args(args)
autograd.backward(stage_outputs, grad_tensors=grad_tensors)
# collect grad of input tensor
consume_result = []
if not is_first_stage:
for input_node in stage_inputs:
if isinstance(input_node, torch.Tensor):
consume_result.append(input_node.grad)
else:
raise TypeError(f"Unknown phase appears in _consume_work_item_by_phase {phase}")
return consume_result
def _get_store_len(self):
return f'work_list:{len(self.work_list)} output_list:{len(self.output_list)} backward_cache:{len(self.microbatch_id_to_backward_cache)} label_cache:{len(self.microbatch_id_to_labels)}'
def _get_parameter_grad_sum(self):
grad_sum = 0
for p in self.module_partition.parameters():
if p.grad is not None:
grad_sum += p.grad.sum()
return grad_sum
def _is_first_step(self, work_item: WorkItem) -> bool:
return work_item.phase == Phase.FORWARD and work_item.microbatch_id == 0
def _is_last_step(self, work_item: WorkItem) -> bool:
if work_item.forward_only:
last_phase = Phase.FORWARD
else:
last_phase = Phase.BACKWARD
is_last_phase = work_item.phase == last_phase
is_last_microbatch = work_item.microbatch_id == self.num_microbatches - 1
return is_last_phase and is_last_microbatch
def _hook_before_step(self):
pass
def _reset_context(self):
self.forward_times = 0
self.backward_times = 0
self.outstanding = 0
self._initialize_outstanding_range()
# do the main loop to consume ready_list
def _work_loop(self):
# for init
self._get_producer_consumer()
# main loop
while True:
work_item_key = self._get_work_item_key()
# move current work item to output_list to activate subscribe in advance
with self.work_list_condition_lock:
work_item = self.work_list.pop(work_item_key)
color_debug(
f'rank {self.pp_rank} get a key : {work_item_key} work_item args: {tensor_shape_list(work_item.args)} {self._get_store_len()}',
'work loop', 'green')
with self.output_list_condition_lock:
# assert work_item_key not in self.output_list
self.output_list[work_item_key] = work_item
self.output_list_condition_lock.notify_all()
consume_result = self._consume_work_item_by_phase(work_item)
color_debug(
f'rank_{self.pp_rank} [{work_item.phase}] finish consuming, result is {tensor_shape_list(consume_result)} {self._get_store_len()} | {self.work_list.keys()} | {self.output_list.keys()}',
'work loop', 'green')
work_item.output.set_result(consume_result)
# if is last step in one batch reset context and do step
if self._is_last_step(work_item):
self._hook_before_step()
if hasattr(self, 'optimizer') and not work_item.forward_only:
self.step()
self._reset_context()
def initialize_optimizer(self, optimizer_class: type, **kwargs):
self.optimizer: optim.Optimizer = optimizer_class(self.module_partition.parameters(), **kwargs)
self.step_lock = threading.Lock()
self.step_lock.acquire()
def wait_for_step(self):
self.step_lock.acquire()
def step(self):
self.optimizer.step()
self.optimizer.zero_grad()
self.step_lock.release()
class PipelineEngineBase(ABC, nn.Module):
def __init__(self,
worker_type,
partition_fn: Callable,
stage_num,
num_microbatches,
device: str,
use_1F1B=False,
chunk: int = 1,
criterion: Callable = None,
metric: Callable = None,
checkpoint: bool = False) -> None:
super().__init__()
self.worker_type = worker_type
self.partition_fn: Callable = partition_fn
self.chunk = chunk
self.criterion = criterion
self.metric = metric
self.num_microbatches = num_microbatches
self.device = device
self.use_1F1B = use_1F1B
self.stage_num = stage_num
self.checkpoint = checkpoint
self.pp_rank_to_worker_rref: Dict[int, PyRRef] = dict()
self.step_futs: List[Future] = []
self._check_argument()
self._create_pp_rank_to_rpc_worker_id()
self._create_pp_rank_to_module_partition_id()
self._init_worker()
def _check_argument(self) -> None:
self.virtual_stage_num = self.stage_num * self.chunk
assert self.stage_num <= torch.cuda.device_count(), "stage_num must be smaller than device count!"
def _get_actual_stage_num(self) -> int:
return self.stage_num if self.chunk == 1 else self.virtual_stage_num
def _create_pp_rank_to_rpc_worker_id(self) -> None:
"""create a map from model partition to stage_id, which is useful when use_interleave is True.
e.g. If a model is splited into 4 parts, which means stage_num is 2, chunk is 2, then
pp_rank_to_rpc_worker_id = [0, 1, 0, 1], that means first and third part
of partitions will be moved to device 0 and the others to device 1
"""
stage_num = self.stage_num
actual_stage_num = self._get_actual_stage_num()
self.pp_rank_to_rpc_worker_id = [0] * actual_stage_num
for pp_rank in range(actual_stage_num):
self.pp_rank_to_rpc_worker_id[pp_rank] = pp_rank % stage_num
def _create_pp_rank_to_module_partition_id(self) -> None:
"""By default(both fill drain and 1F1B), length of model partitions equal to
actual_stage_num, so allocate model partition to corresponding stage
"""
actual_stage_num = self._get_actual_stage_num()
self.pp_rank_to_module_partition_id = [0] * actual_stage_num
for pp_rank in range(actual_stage_num):
self.pp_rank_to_module_partition_id[pp_rank] = pp_rank
def _init_worker(self) -> None:
actual_stage_num = self._get_actual_stage_num()
worker_type = self.worker_type
checkpoint = self.checkpoint
num_microbatches = self.num_microbatches
device = self.device
criterion = self.criterion
metric = self.metric
partition_fn = self.partition_fn
chunk = self.chunk
for pp_rank in range(len(self.pp_rank_to_rpc_worker_id)):
partition_id = self.pp_rank_to_module_partition_id[pp_rank]
partition_args = (partition_id, chunk, actual_stage_num)
rpc_worker_id = self.pp_rank_to_rpc_worker_id[pp_rank]
if device[:4] == 'cuda':
device = f'cuda:{rpc_worker_id}'
self.pp_rank_to_worker_rref[pp_rank] = rpc.remote(rpc_worker_id,
worker_type,
args=(partition_fn, partition_args, pp_rank,
actual_stage_num, num_microbatches, device,
criterion, metric, checkpoint))
# let each worker know global worker rref (include itself)
sync_futs = []
for pp_rank in self.pp_rank_to_worker_rref:
fut = self.pp_rank_to_worker_rref[pp_rank].rpc_async().sync_global_worker_rrefs(self.pp_rank_to_worker_rref)
sync_futs.append(fut)
for fut in sync_futs:
fut.wait()
def remote_parameters(self) -> Dict[int, List[torch.Tensor]]:
parameters = {}
actual_stage_num = self._get_actual_stage_num()
for stage_id in range(actual_stage_num):
parameters[stage_id] = []
worker_rref = self.pp_rank_to_worker_rref[stage_id]
for p in worker_rref.rpc_sync().get_parameters():
parameters[stage_id].append(p)
return parameters
def remote_grad(self) -> Dict[int, List[torch.Tensor]]:
grads = {}
actual_stage_num = self._get_actual_stage_num()
for stage_id in range(actual_stage_num):
grads[stage_id] = []
worker_rref = self.pp_rank_to_worker_rref[stage_id]
for grad in worker_rref.rpc_sync().get_parameter_gradients():
grads[stage_id].append(grad)
return grads
def get_input_pp_ranks(self) -> List[int]:
return [0]
def get_output_pp_ranks(self) -> List[int]:
return [self._get_actual_stage_num() - 1]
def _consume_constraint(self, microbatch_id: int, forward_only: bool, input_pp_ranks: List[int],
output_pp_ranks: List[int], ret_future):
actual_stage_num = self._get_actual_stage_num()
use_1F1B = self.use_1F1B
if microbatch_id >= actual_stage_num:
if forward_only or not use_1F1B:
for pp_rank in output_pp_ranks:
ret_future[pp_rank][microbatch_id - actual_stage_num].wait()
else:
key = UniqueKey(microbatch_id - actual_stage_num, Phase.BACKWARD)
for pp_rank in input_pp_ranks:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
worker_rref.rpc_sync().get_output_by_key(key)
def _create_ret_future(self, output_pp_ranks: List[int]) -> Dict[int, List[Future]]:
num_microbatches = self.num_microbatches
return {pp_rank: [None] * num_microbatches for pp_rank in output_pp_ranks}
def _set_input(self, input_pp_ranks: List[int], microbatch_id: int, microbatch, forward_only: bool):
for pp_rank in input_pp_ranks:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
# TODO : add relationship between input_pp_ranks and parts of microbatch
worker_rref.remote().set_input(microbatch_id, microbatch, forward_only)
def _set_labels(self, output_pp_ranks: List[int], microbatch_id: int, microlabels):
for pp_rank in output_pp_ranks:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
# TODO : add relationship between output_pp_ranks and parts of microlabels
worker_rref.remote().set_labels(microbatch_id, microlabels)
def _subscribe_forward(self, microbatch_id: int, output_pp_ranks: List[int], ret_future: Dict[int, List[Future]]):
key = UniqueKey(microbatch_id, Phase.FORWARD)
for pp_rank in output_pp_ranks:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
ret_future[pp_rank][microbatch_id] = worker_rref.rpc_async().get_output_by_key(key)
def _ensure_backward(self, forward_only: bool, input_pp_ranks: List[int]):
if not forward_only:
for pp_rank in input_pp_ranks:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
key = UniqueKey(self.num_microbatches - 1, Phase.BACKWARD)
worker_rref.rpc_sync().get_output_by_key(key)
def _collect_forward_result(self, output_pp_ranks: List[int], ret_future: Dict[int, List[Future]]):
forward_result = []
for pp_rank in output_pp_ranks:
worker_forward_result = [None] * self.num_microbatches
for microbatch_id in range(self.num_microbatches):
ret = ret_future[pp_rank][microbatch_id].wait()
worker_forward_result[microbatch_id] = ret
worker_forward_result = list(zip(*worker_forward_result))
forward_result.extend(worker_forward_result)
return forward_result
def forward_backward(self, batch: torch.Tensor, labels: torch.Tensor = None, forward_only: bool = False):
if labels is not None:
assert len(batch) == len(labels)
if not forward_only:
assert hasattr(self, 'optimizer_class')
num_microbatches = self.num_microbatches
microbatch_size = len(batch) // num_microbatches
# If Chimera mode is used, then rank of down pipeline is excluded from 'input_pp_ranks' or 'output_pp_ranks'
input_pp_ranks = self.get_input_pp_ranks()
output_pp_ranks = self.get_output_pp_ranks()
# a cache to collect data and control flow
ret_future = self._create_ret_future(output_pp_ranks)
for microbatch_id in range(num_microbatches):
# control data input speed
# to prevent exceed of wait limitations
self._consume_constraint(microbatch_id, forward_only, input_pp_ranks, output_pp_ranks, ret_future)
# set input
microbatch = batch[microbatch_size * microbatch_id:microbatch_size * (microbatch_id + 1)]
microbatch = microbatch.cuda()
self._set_input(input_pp_ranks, microbatch_id, microbatch, forward_only)
# set labels
if labels is not None:
microlabels = labels[microbatch_size * microbatch_id:microbatch_size * (microbatch_id + 1)]
microlabels = microlabels.cuda()
self._set_labels(output_pp_ranks, microbatch_id, microlabels)
# get data asynchronously
self._subscribe_forward(microbatch_id, output_pp_ranks, ret_future)
# wait for first rank to ensure all backwards are done
self._ensure_backward(forward_only, input_pp_ranks)
# collect forward result
forward_result = self._collect_forward_result(output_pp_ranks, ret_future)
if not forward_only and hasattr(self, 'optimizer_class'):
# wait for all step
for pp_rank in self.pp_rank_to_worker_rref:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
worker_rref.rpc_sync().wait_for_step()
return forward_result
def initialize_optimizer(self, optimizer_class: type, **kwargs):
self.optimizer_class = optimizer_class
for pp_rank in self.pp_rank_to_worker_rref:
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
worker_rref.remote().initialize_optimizer(optimizer_class, **kwargs)
def step(self):
actual_stage_num = self._get_actual_stage_num()
for pp_rank in range(actual_stage_num):
worker_rref = self.pp_rank_to_worker_rref[pp_rank]
fut = worker_rref.rpc_async().step()
self.step_futs.append(fut)
for fut in self.step_futs:
fut.wait()