lightning/pytorch_lightning/trainer/logging.py

206 lines
6.8 KiB
Python

from abc import ABC
from typing import Union, Iterable
import torch
from pytorch_lightning.core import memory
from pytorch_lightning.loggers import TensorBoardLogger, LightningLoggerBase, LoggerCollection
from pytorch_lightning.utilities import memory_utils
class TrainerLoggingMixin(ABC):
# this is just a summary on variables used in this abstract class,
# the proper values/initialisation should be done in child class
current_epoch: int
on_gpu: bool
log_gpu_memory: ...
logger: Union[LightningLoggerBase, bool]
tqdm_metrics: ...
global_step: int
proc_rank: int
use_dp: bool
use_ddp2: bool
default_root_dir: str
slurm_job_id: int
num_gpus: int
def configure_logger(self, logger):
if logger is True:
# default logger
self.logger = TensorBoardLogger(
save_dir=self.default_root_dir,
version=self.slurm_job_id,
name='lightning_logs'
)
self.logger.rank = 0
elif logger is False:
self.logger = None
else:
if isinstance(logger, Iterable):
self.logger = LoggerCollection(logger)
else:
self.logger = logger
self.logger.rank = 0
def log_metrics(self, metrics, grad_norm_dic, step=None):
"""Logs the metric dict passed in.
If `step` parameter is None and `step` key is presented is metrics,
uses metrics["step"] as a step
Args:
metrics (dict): Metric values
grad_norm_dic (dict): Gradient norms
step (int): Step for which metrics should be logged. Default value corresponds to `self.global_step`
"""
# add gpu memory
if self.on_gpu and self.log_gpu_memory:
mem_map = memory.get_memory_profile(self.log_gpu_memory)
metrics.update(mem_map)
# add norms
metrics.update(grad_norm_dic)
# turn all tensors to scalars
scalar_metrics = self.metrics_to_scalars(metrics)
if "step" in scalar_metrics and step is None:
step = scalar_metrics.pop("step")
else:
# added metrics by Lightning for convenience
metrics['epoch'] = self.current_epoch
step = step if step is not None else self.global_step
# log actual metrics
if self.proc_rank == 0 and self.logger is not None:
self.logger.agg_and_log_metrics(scalar_metrics, step=step)
self.logger.save()
def add_tqdm_metrics(self, metrics):
for k, v in metrics.items():
if isinstance(v, torch.Tensor):
v = v.item()
self.tqdm_metrics[k] = v
def metrics_to_scalars(self, metrics):
new_metrics = {}
for k, v in metrics.items():
if isinstance(v, torch.Tensor):
v = v.item()
if isinstance(v, dict):
v = self.metrics_to_scalars(v)
new_metrics[k] = v
return new_metrics
def process_output(self, output, train=False):
"""Reduces output according to the training mode.
Separates loss from logging and tqdm metrics
"""
# ---------------
# EXTRACT CALLBACK KEYS
# ---------------
# all keys not progress_bar or log are candidates for callbacks
callback_metrics = {}
for k, v in output.items():
if k not in ['progress_bar', 'log', 'hiddens']:
callback_metrics[k] = v
if train and (self.use_dp or self.use_ddp2):
num_gpus = self.num_gpus
callback_metrics = self.reduce_distributed_output(callback_metrics, num_gpus)
# ---------------
# EXTRACT PROGRESS BAR KEYS
# ---------------
try:
progress_output = output['progress_bar']
# reduce progress metrics for tqdm when using dp
if train and (self.use_dp or self.use_ddp2):
num_gpus = self.num_gpus
progress_output = self.reduce_distributed_output(progress_output, num_gpus)
progress_bar_metrics = progress_output
except Exception:
progress_bar_metrics = {}
# ---------------
# EXTRACT LOGGING KEYS
# ---------------
# extract metrics to log to experiment
try:
log_output = output['log']
# reduce progress metrics for tqdm when using dp
if train and (self.use_dp or self.use_ddp2):
num_gpus = self.num_gpus
log_output = self.reduce_distributed_output(log_output, num_gpus)
log_metrics = log_output
except Exception:
log_metrics = {}
# ---------------
# EXTRACT LOSS
# ---------------
# if output dict doesn't have the keyword loss
# then assume the output=loss if scalar
loss = None
if train:
try:
loss = output['loss']
except Exception:
if isinstance(output, torch.Tensor):
loss = output
else:
raise RuntimeError(
'No `loss` value in the dictionary returned from `model.training_step()`.'
)
# when using dp need to reduce the loss
if self.use_dp or self.use_ddp2:
loss = self.reduce_distributed_output(loss, self.num_gpus)
# ---------------
# EXTRACT HIDDEN
# ---------------
hiddens = output.get('hiddens')
# use every metric passed in as a candidate for callback
callback_metrics.update(progress_bar_metrics)
callback_metrics.update(log_metrics)
# detach all metrics for callbacks to prevent memory leaks
# no .item() because it will slow things down
callback_metrics = memory_utils.recursive_detach(callback_metrics)
return loss, progress_bar_metrics, log_metrics, callback_metrics, hiddens
def reduce_distributed_output(self, output, num_gpus):
if num_gpus <= 1:
return output
# when using DP, we get one output per gpu
# average outputs and return
if isinstance(output, torch.Tensor):
return output.mean()
for k, v in output.items():
# recurse on nested dics
if isinstance(output[k], dict):
output[k] = self.reduce_distributed_output(output[k], num_gpus)
# do nothing when there's a scalar
elif isinstance(output[k], torch.Tensor) and output[k].dim() == 0:
pass
# reduce only metrics that have the same number of gpus
elif output[k].size(0) == num_gpus:
reduced = torch.mean(output[k])
output[k] = reduced
return output