Source code for lightning.pytorch.profilers.pytorch

# Copyright The Lightning AI team.
# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.
"""Profiler to check if there are any bottlenecks in your code."""
import inspect
import logging
import os
from functools import lru_cache, partial
from pathlib import Path
from typing import Any, Callable, ContextManager, Dict, List, Optional, Type, TYPE_CHECKING, Union

import torch
from torch import nn, Tensor
from torch.autograd.profiler import record_function

from lightning.fabric.accelerators.cuda import is_cuda_available
from lightning.pytorch.profilers.profiler import Profiler
from lightning.pytorch.utilities.exceptions import MisconfigurationException
from lightning.pytorch.utilities.imports import _KINETO_AVAILABLE
from lightning.pytorch.utilities.rank_zero import rank_zero_warn, WarningCache

    from torch.autograd.profiler import EventList
    from torch.utils.hooks import RemovableHandle

    from lightning.pytorch.core.module import LightningModule

    from torch.profiler import ProfilerAction, ProfilerActivity, tensorboard_trace_handler

log = logging.getLogger(__name__)
warning_cache = WarningCache()

_PROFILER = Union[torch.profiler.profile, torch.autograd.profiler.profile, torch.autograd.profiler.emit_nvtx]

class RegisterRecordFunction:
    """While profiling autograd operations, this class will add labels for module names around the forward function.

    The Lightning PyTorch Profiler will activate this feature automatically. It can be deactivated as follows:

        from lightning.pytorch.profilers import PyTorchProfiler
        profiler = PyTorchProfiler(record_module_names=False)

    It can be used outside of Lightning as follows:

        from lightning.pytorch import Trainer, seed_everything
        with RegisterRecordFunction(model):
            out = model(batch)


    def __init__(self, model: nn.Module) -> None:
        self._model = model
        self._records: Dict[str, record_function] = {}
        self._handles: Dict[str, List["RemovableHandle"]] = {}

    def _start_recording_forward(self, _: nn.Module, input: Tensor, record_name: str) -> Tensor:
        # Add [pl][module] in name for pytorch profiler to recognize
        record = record_function("[pl][module]" + record_name)
        self._records[record_name] = record
        return input

    def _stop_recording_forward(self, _: nn.Module, __: Tensor, output: Tensor, record_name: str) -> Tensor:
        self._records[record_name].__exit__(None, None, None)
        return output

    def __enter__(self) -> None:
        for module_name, module in self._model.named_modules():
            if module_name:
                full_name = f"{type(module).__module__}.{type(module).__name__}"
                record_name = f"{full_name}: {module_name}"
                pre_forward_handle = module.register_forward_pre_hook(
                    partial(self._start_recording_forward, record_name=record_name)
                post_forward_handle = module.register_forward_hook(
                    partial(self._stop_recording_forward, record_name=record_name)

                self._handles[module_name] = [pre_forward_handle, post_forward_handle]

    def __exit__(self, type: Any, value: Any, traceback: Any) -> None:
        for handles in self._handles.values():
            for h in handles:
        self._handles = {}

class ScheduleWrapper:
    """This class is used to override the schedule logic from the profiler and perform recording for both
    `training_step`, `validation_step`."""

    def __init__(self, schedule: Callable) -> None:
        if not _KINETO_AVAILABLE:
            raise ModuleNotFoundError("You are trying to use `ScheduleWrapper` which require kineto install.")
        self._schedule = schedule

    def reset(self) -> None:
        # handle properly `fast_dev_run`. PyTorch Profiler will fail otherwise.
        self._num_training_step = 0
        self._num_validation_step = 0
        self._num_test_step = 0
        self._num_predict_step = 0
        self._training_step_reached_end = False
        self._validation_step_reached_end = False
        self._test_step_reached_end = False
        self._predict_step_reached_end = False
        # used to stop profiler when `ProfilerAction.RECORD_AND_SAVE` is reached.
        self._current_action: Optional[str] = None
        self._prev_schedule_action: Optional[ProfilerAction] = None
        self._start_action_name: Optional[str] = None

    def setup(self, start_action_name: str) -> None:
        self._start_action_name = start_action_name

    def pre_step(self, current_action: str) -> None:
        self._current_action = current_action

    def is_training(self) -> bool:
        assert self._current_action is not None
        return self._current_action.endswith("training_step")

    def is_validating(self) -> bool:
        assert self._current_action is not None
        return self._current_action.endswith("validation_step")

    def is_testing(self) -> bool:
        assert self._current_action is not None
        return self._current_action.endswith("test_step")

    def is_predicting(self) -> bool:
        assert self._current_action is not None
        return self._current_action.endswith("predict_step")

    def num_step(self) -> int:
        if self.is_training:
            return self._num_training_step
        if self.is_validating:
            return self._num_validation_step
        if self.is_testing:
            return self._num_test_step
        if self.is_predicting:
            return self._num_predict_step
        return 0

    def _step(self) -> None:
        if self.is_training:
            self._num_training_step += 1
        elif self.is_validating:
            assert self._start_action_name is not None
            if self._start_action_name.endswith("on_fit_start"):
                if self._num_training_step > 0:
                    self._num_validation_step += 1
                self._num_validation_step += 1
        elif self.is_testing:
            self._num_test_step += 1
        elif self.is_predicting:
            self._num_predict_step += 1

    def has_finished(self) -> bool:
        if self.is_training:
            return self._training_step_reached_end
        if self.is_validating:
            return self._validation_step_reached_end
        if self.is_testing:
            return self._test_step_reached_end
        if self.is_predicting:
            return self._predict_step_reached_end
        return False

    def __call__(self, num_step: int) -> "ProfilerAction":
        # ignore the provided input. Keep internal state instead.
        if self._current_action is None or self.has_finished:
            return ProfilerAction.NONE

        action = self._schedule(max(self.num_step, 0))
        if self._prev_schedule_action == ProfilerAction.RECORD and action == ProfilerAction.WARMUP:
            # Work around the corner case when validation starts before train.
            # In this case, the action is RECORD in validation loop, and then call into the train
            # and the action is still WARMUP in train and pytorch will recognize this as error.
            action = ProfilerAction.RECORD
        if action == ProfilerAction.RECORD_AND_SAVE:
            if self.is_training:
                self._training_step_reached_end = True
            elif self.is_validating:
                self._validation_step_reached_end = True
            elif self.is_testing:
                self._test_step_reached_end = True
            elif self.is_predicting:
                self._predict_step_reached_end = True
        self._prev_schedule_action = action
        return action

[docs]class PyTorchProfiler(Profiler): STEP_FUNCTIONS = {"training_step", "validation_step", "test_step", "predict_step"} AVAILABLE_SORT_KEYS = { "cpu_time", "cuda_time", "cpu_time_total", "cuda_time_total", "cpu_memory_usage", "cuda_memory_usage", "self_cpu_memory_usage", "self_cuda_memory_usage", "count", } def __init__( self, dirpath: Optional[Union[str, Path]] = None, filename: Optional[str] = None, group_by_input_shapes: bool = False, emit_nvtx: bool = False, export_to_chrome: bool = True, row_limit: int = 20, sort_by_key: Optional[str] = None, record_module_names: bool = True, **profiler_kwargs: Any, ) -> None: r"""This profiler uses PyTorch's Autograd Profiler and lets you inspect the cost of. different operators inside your model - both on the CPU and GPU Args: dirpath: Directory path for the ``filename``. If ``dirpath`` is ``None`` but ``filename`` is present, the ``trainer.log_dir`` (from :class:`~lightning.pytorch.loggers.tensorboard.TensorBoardLogger`) will be used. filename: If present, filename where the profiler results will be saved instead of printing to stdout. The ``.txt`` extension will be used automatically. group_by_input_shapes: Include operator input shapes and group calls by shape. emit_nvtx: Context manager that makes every autograd operation emit an NVTX range Run:: nvprof --profile-from-start off -o -- <regular command here> To visualize, you can either use:: nvvp torch.autograd.profiler.load_nvprof(path) export_to_chrome: Whether to export the sequence of profiled operators for Chrome. It will generate a ``.json`` file which can be read by Chrome. row_limit: Limit the number of rows in a table, ``-1`` is a special value that removes the limit completely. sort_by_key: Attribute used to sort entries. By default they are printed in the same order as they were registered. Valid keys include: ``cpu_time``, ``cuda_time``, ``cpu_time_total``, ``cuda_time_total``, ``cpu_memory_usage``, ``cuda_memory_usage``, ``self_cpu_memory_usage``, ``self_cuda_memory_usage``, ``count``. record_module_names: Whether to add module names while recording autograd operation. \**profiler_kwargs: Keyword arguments for the PyTorch profiler. This depends on your PyTorch version Raises: MisconfigurationException: If arg ``sort_by_key`` is not present in ``AVAILABLE_SORT_KEYS``. If arg ``schedule`` is not a ``Callable``. If arg ``schedule`` does not return a ``torch.profiler.ProfilerAction``. """ super().__init__(dirpath=dirpath, filename=filename) self._group_by_input_shapes = group_by_input_shapes and profiler_kwargs.get("record_shapes", False) self._emit_nvtx = emit_nvtx self._export_to_chrome = export_to_chrome self._row_limit = row_limit self._sort_by_key = sort_by_key or f"{'cuda' if profiler_kwargs.get('use_cuda', False) else 'cpu'}_time_total" self._record_module_names = record_module_names self._profiler_kwargs = profiler_kwargs self.profiler: Optional[_PROFILER] = None self.function_events: Optional["EventList"] = None self._lightning_module: Optional["LightningModule"] = None # set by ProfilerConnector self._register: Optional[RegisterRecordFunction] = None self._parent_profiler: Optional[ContextManager] = None self._recording_map: Dict[str, record_function] = {} self._start_action_name: Optional[str] = None self._schedule: Optional[ScheduleWrapper] = None if _KINETO_AVAILABLE: self._init_kineto(profiler_kwargs) if self._sort_by_key not in self.AVAILABLE_SORT_KEYS: raise MisconfigurationException( f"Found sort_by_key: {self._sort_by_key}. Should be within {self.AVAILABLE_SORT_KEYS}. " ) def _init_kineto(self, profiler_kwargs: Any) -> None: has_schedule = "schedule" in profiler_kwargs self._has_on_trace_ready = "on_trace_ready" in profiler_kwargs schedule = profiler_kwargs.get("schedule", None) if schedule is not None: if not callable(schedule): raise MisconfigurationException(f"Schedule should be a callable. Found: {schedule}") action = schedule(0) if not isinstance(action, ProfilerAction): raise MisconfigurationException( f"Schedule should return a `torch.profiler.ProfilerAction`. Found: {action}" ) self._default_schedule() schedule = schedule if has_schedule else self._default_schedule() self._schedule = ScheduleWrapper(schedule) if schedule is not None else schedule self._profiler_kwargs["schedule"] = self._schedule activities = profiler_kwargs.get("activities", None) self._profiler_kwargs["activities"] = activities or self._default_activities() self._export_to_flame_graph = profiler_kwargs.get("export_to_flame_graph", False) self._metric = profiler_kwargs.get("metric", "self_cpu_time_total") with_stack = profiler_kwargs.get("with_stack", False) or self._export_to_flame_graph self._profiler_kwargs["with_stack"] = with_stack @property def _total_steps(self) -> Union[int, float]: assert self._schedule is not None assert self._lightning_module is not None trainer = self._lightning_module.trainer if self._schedule.is_training: return trainer.num_training_batches if self._schedule.is_validating: return sum(trainer.num_val_batches) + sum(trainer.num_sanity_val_batches) if self._schedule.is_testing: return sum(trainer.num_test_batches) if self._schedule.is_predicting: return sum(trainer.num_predict_batches) raise NotImplementedError("Unsupported schedule") def _should_override_schedule(self) -> bool: return ( self._lightning_module is not None and self._schedule is not None and self._total_steps < 5 and self._schedule._schedule == self._default_schedule() ) @staticmethod @lru_cache(1) def _default_schedule() -> Optional[Callable]: if _KINETO_AVAILABLE: # Those schedule defaults allow the profiling overhead to be negligible over training time. return torch.profiler.schedule(wait=1, warmup=1, active=3) return None def _default_activities(self) -> List["ProfilerActivity"]: activities: List["ProfilerActivity"] = [] if not _KINETO_AVAILABLE: return activities if self._profiler_kwargs.get("use_cpu", True): activities.append(ProfilerActivity.CPU) if self._profiler_kwargs.get("use_cuda", is_cuda_available()): activities.append(ProfilerActivity.CUDA) return activities
[docs] def start(self, action_name: str) -> None: if self.profiler is None: # close profiler if it is already opened. might happen if 2 profilers # are created and the first one did not call `describe` if torch.autograd._profiler_enabled(): torch.autograd._disable_profiler() if self._schedule is not None: self._schedule.setup(action_name) self._create_profilers() profiler = self.profiler.__enter__() if profiler is not None: self.profiler = profiler if self._parent_profiler is not None: self._parent_profiler.__enter__() if self._lightning_module is not None and self._register is None and self._record_module_names: self._register = RegisterRecordFunction(self._lightning_module) self._register.__enter__() if self.profiler is not None and action_name not in self._recording_map: # Add [pl][profile] in name for pytorch profiler to recognize recording = record_function("[pl][profile]" + action_name) recording.__enter__() self._recording_map[action_name] = recording
[docs] def stop(self, action_name: str) -> None: if action_name in self._recording_map: self._recording_map[action_name].__exit__(None, None, None) del self._recording_map[action_name] if not _KINETO_AVAILABLE or self._emit_nvtx: return if self.profiler is not None and any(action_name.endswith(func) for func in self.STEP_FUNCTIONS): assert isinstance(self.profiler, torch.profiler.profile) if self._schedule is not None: self._schedule.pre_step(action_name) # the default schedule requires a minimum of 5 steps to properly work: `wait=1, warmup=1, active=3`. # otherwise, this will raise a `segmentation fault`. if self._should_override_schedule(): warning_cache.warn( "The PyTorch Profiler default schedule will be overridden as there is not enough " "steps to properly record traces." ) self._schedule = None self.profiler.schedule = torch.profiler.profiler._default_schedule_fn def on_trace_ready(profiler: _PROFILER) -> None: if self.dirpath is not None: if self._export_to_chrome: handler = tensorboard_trace_handler( str(self.dirpath), self._prepare_filename(action_name=action_name, extension="") ) handler(profiler) if self._export_to_flame_graph: path = os.path.join( self.dirpath, self._prepare_filename(action_name=action_name, extension=".stack") ) assert isinstance(profiler, torch.autograd.profiler.profile) profiler.export_stacks(path, metric=self._metric) else: rank_zero_warn("The PyTorchProfiler failed to export trace as `dirpath` is None") if not self._has_on_trace_ready: self.profiler.on_trace_ready = on_trace_ready if self._schedule is not None: self.profiler.step_num = self._schedule.num_step self.profiler.step() self.profiler.add_metadata("Framework", "pytorch-lightning")
def summary(self) -> str: if not self._profiler_kwargs.get("enabled", True) or self._emit_nvtx: return "" self._delete_profilers() if not self.function_events: return "" if self._export_to_chrome and not _KINETO_AVAILABLE: filename = f"{self.local_rank}_trace.json" path_to_trace = filename if self.dirpath is None else os.path.join(self.dirpath, filename) self.function_events.export_chrome_trace(path_to_trace) data = self.function_events.key_averages(group_by_input_shapes=self._group_by_input_shapes) table = data.table(sort_by=self._sort_by_key, row_limit=self._row_limit) recorded_stats = {"records": table} return self._stats_to_str(recorded_stats) def _create_profilers(self) -> None: if self.profiler is not None: return if self._emit_nvtx: if self._parent_profiler is None: self._parent_profiler = torch.cuda.profiler.profile() self.profiler = self._create_profiler(torch.autograd.profiler.emit_nvtx) else: self._parent_profiler = None self.profiler = self._create_profiler( torch.profiler.profile if _KINETO_AVAILABLE else torch.autograd.profiler.profile ) def _create_profiler(self, profiler: Type[_PROFILER]) -> _PROFILER: init_parameters = inspect.signature(profiler.__init__).parameters kwargs = {k: v for k, v in self._profiler_kwargs.items() if k in init_parameters} return profiler(**kwargs) def _cache_functions_events(self) -> None: if self._emit_nvtx: return if _KINETO_AVAILABLE: assert isinstance(self.profiler, torch.profiler.profile) self.function_events = else: assert isinstance(self.profiler, torch.autograd.profiler.profile) self.function_events = self.profiler.function_events def _delete_profilers(self) -> None: if self.profiler is not None: self.profiler.__exit__(None, None, None) self._cache_functions_events() self.profiler = None if self._schedule is not None: self._schedule.reset() if self._parent_profiler is not None: self._parent_profiler.__exit__(None, None, None) self._parent_profiler = None if self._register is not None: self._register.__exit__(None, None, None) self._register = None
[docs] def teardown(self, stage: Optional[str]) -> None: self._delete_profilers() for k in list(self._recording_map): self.stop(k) self._recording_map = {} super().teardown(stage=stage)

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