DeepLearningExamples/PyTorch/Translation/Transformer/multiprocessing_train.py
2019-01-23 17:03:45 +01:00

89 lines
2.8 KiB
Python

#!/usr/bin/env python3 -u
# Copyright (c) 2017-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the license found in the LICENSE file in
# the root directory of this source tree. An additional grant of patent rights
# can be found in the PATENTS file in the same directory.
import os
import random
import signal
import torch
from fairseq import distributed_utils, options
from train import main as single_process_main
def main(args):
# Set distributed training parameters for a single node.
args.distributed_world_size = torch.cuda.device_count()
args.distributed_init_method = 'tcp://localhost:{port}'.format(
port=random.randint(10000, 20000))
mp = torch.multiprocessing.get_context('spawn')
# Create a thread to listen for errors in the child processes.
error_queue = mp.SimpleQueue()
error_handler = ErrorHandler(error_queue)
# Train with multiprocessing.
procs = []
for i in range(args.distributed_world_size):
args.distributed_rank = i
args.device_id = i
procs.append(mp.Process(target=run, args=(args, error_queue, ), daemon=True))
procs[i].start()
error_handler.add_child(procs[i].pid)
for p in procs:
p.join()
def run(args, error_queue):
try:
args.distributed_rank = distributed_utils.distributed_init(args)
single_process_main(args)
except KeyboardInterrupt:
pass # killed by parent, do nothing
except Exception:
# propagate exception to parent process, keeping original traceback
import traceback
error_queue.put((args.distributed_rank, traceback.format_exc()))
class ErrorHandler(object):
"""A class that listens for exceptions in children processes and propagates
the tracebacks to the parent process."""
def __init__(self, error_queue):
import signal
import threading
self.error_queue = error_queue
self.children_pids = []
self.error_thread = threading.Thread(target=self.error_listener, daemon=True)
self.error_thread.start()
signal.signal(signal.SIGUSR1, self.signal_handler)
def add_child(self, pid):
self.children_pids.append(pid)
def error_listener(self):
(rank, original_trace) = self.error_queue.get()
self.error_queue.put((rank, original_trace))
os.kill(os.getpid(), signal.SIGUSR1)
def signal_handler(self, signalnum, stackframe):
for pid in self.children_pids:
os.kill(pid, signal.SIGINT) # kill children processes
(rank, original_trace) = self.error_queue.get()
msg = "\n\n-- Tracebacks above this line can probably be ignored --\n\n"
msg += original_trace
raise Exception(msg)
if __name__ == '__main__':
parser = options.get_training_parser()
args = options.parse_args_and_arch(parser)
main(args)