dummy_m4 / m4 /utils /activation_tracker.py
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# Copyright 2020 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Adapted from https://github.com/huggingface/transformers/blob/f93c90d21749b61bd89152a7fe99a839df29ed94/src/transformers/debug_utils.py
"""
import json
from transformers.utils import ExplicitEnum, is_torch_available, logging
from m4.training.utils import get_stats
if is_torch_available():
import torch
logger = logging.get_logger(__name__)
class ActivationTracker:
"""
This debug class helps detect and understand where the model starts getting very large or very small, and more
importantly `nan` or `inf` activation elements.
This class will plug hooks into the model and record the activation values of the model into a list of dictionaries: `jsonl_stats`.
Recording is only active during training, not during validation, and when `trace_activation` is set to True.
In practise, since this tracking requires additional computation, we only track activations every X steps.
In the case of gradient accumulation, all the batches being accumulated are being recorded and identified by the `batch_idx` key.
Args:
model (`nn.Module`):
The model to debug.
abort_after_batch_num (`int``, *optional*):
Whether to abort after a certain batch number has finished
"""
def __init__(
self,
model,
abort_after_batch_num=None,
):
self.model = model
self.is_validation = False
self.abort_after_batch_num = abort_after_batch_num
self.jsonl_stats = []
self.batch_number = 0
self.detected_overflow = False
self.analyse_model()
self.register_forward_hook()
def analyse_model(self):
# extract the fully qualified module names, to be able to report at run time. e.g.:
# encoder.block.2.layer.0.SelfAttention.o
#
# for shared weights only the first shared module name will be registered
self.module_names = {m: name for name, m in self.model.named_modules()}
def analyse_variable(self, var, ctx, current_module_stats):
if torch.is_tensor(var):
dict_stats = get_stats(var, ctx)
current_module_stats.update(dict_stats)
# self.expand_frame(text_stats)
if detect_overflow(var, ctx):
self.detected_overflow = True
return current_module_stats
def create_frame(self, module, input, output):
module_name = f"{self.module_names[module]}"
module_type = f"{module.__class__.__name__}"
current_module_stats = {}
# inputs
if isinstance(input, tuple):
for i, x in enumerate(input):
current_module_stats = self.analyse_variable(x, f"input[{i}]", current_module_stats)
else:
current_module_stats = self.analyse_variable(input, "input", current_module_stats)
# outputs
if isinstance(output, tuple):
for i, x in enumerate(output):
# possibly a tuple of tuples
if isinstance(x, tuple):
for j, y in enumerate(x):
current_module_stats = self.analyse_variable(y, f"output[{i}][{j}]", current_module_stats)
else:
current_module_stats = self.analyse_variable(x, f"output[{i}]", current_module_stats)
else:
current_module_stats = self.analyse_variable(output, "output", current_module_stats)
if current_module_stats:
# When we activate gradient checkpointing, the forward hook will be called twice for some (not all) modules.
# That will lead to double (repeated) entries in the list.
# This is a hack to avoid these double entries.
if (module_name, module_type) not in [(x["name"], x["type"]) for x in self.jsonl_stats]:
self.jsonl_stats.append(
{
"name": module_name,
"type": module_type,
**current_module_stats,
}
)
def register_forward_hook(self):
self.model.apply(self._register_forward_hook)
def _register_forward_hook(self, module):
module.register_forward_hook(self.forward_hook)
def forward_hook(self, module, input, output):
# - input is a tuple of packed inputs (could be non-Tensors)
# - output could be a Tensor or a tuple of Tensors and non-Tensors
trace_activation = self.trace_activation
# count batch numbers - the very first forward hook of the batch will be called when the
# batch completes - i.e. it gets called very last - we know this batch has finished
if module == self.model:
self.batch_number += 1
if trace_activation and not self.is_validation:
self.create_frame(module, input, output)
if self.detected_overflow:
# now we can abort, as it's pointless to continue running
raise ValueError(
"DebugUnderflowOverflow: inf/nan detected, aborting as there is no point running further. "
"Please scroll up above this traceback to see the activation values prior to this event."
)
# abort after certain batch if requested to do so
if self.abort_after_batch_num is not None and self.batch_number > self.abort_after_batch_num:
raise ValueError(
f"DebugUnderflowOverflow: aborting after {self.batch_number} batches due to"
f" `abort_after_batch_num={self.abort_after_batch_num}` arg"
)
def fill_in_batch_idx(self, batch_idx):
if not self.jsonl_stats:
return
for r in self.jsonl_stats:
if "batch_idx" not in r:
r["batch_idx"] = batch_idx
else:
if not (r["batch_idx"] <= batch_idx):
raise ValueError("`batch_idx` should be increasing")
def dump_stats(self, log_activations_filename, curr_opt_step):
with open(log_activations_filename, "a") as file:
# append stats to file
for r in self.jsonl_stats:
r["step"] = curr_opt_step
file.write(json.dumps(r) + "\n")
def reset_jsonl_stats(self):
self.jsonl_stats = []
def activate_hooks(self):
self.trace_activation = True
def deactivate_hooks(self):
self.trace_activation = False
def is_eval(self):
self.is_validation = True
def is_train(self):
self.is_validation = False
def detect_overflow(var, ctx):
"""
Report whether the tensor contains any `nan` or `inf` entries.
This is useful for detecting overflows/underflows and best to call right after the function that did some math that
modified the tensor in question.
This function contains a few other helper features that you can enable and tweak directly if you want to track
various other things.
Args:
var: the tensor variable to check
ctx: the message to print as a context
Return:
`True` if `inf` or `nan` was detected, `False` otherwise
"""
detected = False
if torch.isnan(var).any().item():
detected = True
print(f"{ctx} has nans")
if torch.isinf(var).any().item():
detected = True
print(f"{ctx} has infs")
# if needed to monitor large elements can enable the following
if 0: # and detected:
n100 = var[torch.ge(var.abs(), 100)]
if n100.numel() > 0:
print(f"{ctx}: n100={n100.numel()}")
n1000 = var[torch.ge(var.abs(), 1000)]
if n1000.numel() > 0:
print(f"{ctx}: n1000={n1000.numel()}")
n10000 = var[torch.ge(var.abs(), 10000)]
if n10000.numel() > 0:
print(f"{ctx}: n10000={n10000.numel()}")
if 0:
print(f"min={var.min():9.2e} max={var.max():9.2e}")
if 0:
print(f"min={var.min():9.2e} max={var.max():9.2e} var={var.var():9.2e} mean={var.mean():9.2e} ({ctx})")
return detected
class DebugOption(ExplicitEnum):
UNDERFLOW_OVERFLOW = "underflow_overflow"
TPU_METRICS_DEBUG = "tpu_metrics_debug"