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Reorganize examples (#9010)

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* Reorganize example folder

* Continue reorganization

* Change requirements for tests

* Final cleanup

* Finish regroup with tests all passing

* Copyright

* Requirements and readme

* Make a full link for the documentation

* Address review comments

* Apply suggestions from code review

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>

* Add symlink

* Reorg again

* Apply suggestions from code review

Co-authored-by: Thomas Wolf <thomwolf@users.noreply.github.com>

* Adapt title

* Update to new strucutre

* Remove test

* Update READMEs

Co-authored-by: Lysandre Debut <lysandre@huggingface.co>
Co-authored-by: Thomas Wolf <thomwolf@users.noreply.github.com>
This commit is contained in:
Sylvain Gugger
2020-12-11 10:07:02 -05:00
committed by GitHub
parent 86896de064
commit 783d7d2629
215 changed files with 4454 additions and 1193 deletions
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173
examples/research_projects/seq2seq-distillation/make_student.py Normal file
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import warnings
from pathlib import Path
from typing import List, Tuple, Union
import fire
from torch import nn
from transformers import AutoModelForSeq2SeqLM, AutoTokenizer, PreTrainedModel
from transformers.utils import logging
logger = logging.get_logger(__name__)
def copy_layers(src_layers: nn.ModuleList, dest_layers: nn.ModuleList, layers_to_copy: List[int]) -> None:
layers_to_copy = nn.ModuleList([src_layers[i] for i in layers_to_copy])
assert len(dest_layers) == len(layers_to_copy), f"{len(dest_layers)} != {len(layers_to_copy)}"
dest_layers.load_state_dict(layers_to_copy.state_dict())
LAYERS_TO_COPY = {
# maps num layers in teacher -> num_layers in student -> which teacher layers to copy.
# 12: bart, 16: pegasus, 6: marian/Helsinki-NLP
12: {
1: [0], # This says that if the teacher has 12 layers and the student has 1, copy layer 0 of the teacher
2: [0, 6],
3: [0, 6, 11],
4: [0, 4, 8, 11],
6: [0, 2, 4, 7, 9, 11],
9: [0, 1, 2, 4, 5, 7, 9, 10, 11],
12: list(range(12)),
},
16: { # maps num layers in student -> which teacher layers to copy
1: [0],
2: [0, 15],
3: [0, 8, 15],
4: [0, 5, 10, 15],
6: [0, 3, 6, 9, 12, 15],
8: [0, 2, 4, 6, 8, 10, 12, 15],
9: [0, 1, 3, 5, 7, 9, 11, 13, 15],
12: [0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15],
16: list(range(16)),
},
6: {1: [0], 2: [0, 5], 3: [0, 2, 5], 4: [0, 1, 3, 5], 6: list(range(6))},
}
LAYERS_TO_SUPERVISE = {
# maps num layers in student -> which teacher layers to copy.
6: {1: [5], 2: [3, 5], 3: [1, 4, 5], 4: [1, 2, 4, 5]},
12: {1: [11], 2: [5, 11], 3: [3, 7, 11], 6: [1, 3, 5, 8, 10, 11]},
16: {1: [15], 4: [4, 9, 12, 15], 8: [1, 3, 5, 7, 9, 11, 13, 15]},
}
def pick_layers_to_copy(n_student, n_teacher):
try:
val = LAYERS_TO_COPY[n_teacher][n_student]
return val
except KeyError:
if n_student != n_teacher:
warnings.warn(
f"no hardcoded layers to copy for teacher {n_teacher} -> student {n_student}, defaulting to first {n_student}"
)
return list(range(n_student))
def get_layers_to_supervise(n_student, n_teacher) -> List[int]:
"""Used or the --supervise_forward kwarg"""
if n_student > n_teacher:
raise ValueError(f"Cannot perform intermediate supervision for student {n_student} > teacher {n_teacher}")
elif n_teacher == n_student:
return list(range(n_teacher))
elif n_student == 1:
return [n_teacher - 1]
else:
return LAYERS_TO_SUPERVISE[n_teacher][n_student]
def create_student_by_copying_alternating_layers(
teacher: Union[str, PreTrainedModel],
save_path: Union[str, Path] = "student",
e: Union[int, None] = None,
d: Union[int, None] = None,
copy_first_teacher_layers=False,
e_layers_to_copy=None,
d_layers_to_copy=None,
**extra_config_kwargs
) -> Tuple[PreTrainedModel, List[int], List[int]]:
"""Make a student by copying alternating layers from a teacher, save it to save_path.
Args:
teacher: str or PreTrainedModel if str, this will call AutoModelForSeq2SeqLM.from_pretrained(teacher) before
copying layers
save_path: where to save the student, defaults to student directory.
e: how many Encoder layers should the student have, default is fully copy of teacher
d: how many Decoder layers should the student have, default is fully copy of teacher
copy_first_teacher_layers: [bool] dont copy alternating layers, just the first e/d.
**extra_config_kwargs: extra kwargs to pass to the student, by default the teacher config is used.
Returns:
student: new, smaller model. (Also saves it to save_path)
e_layers_to_copy: list of which teacher encoder layers were used
d_layers_to_copy: list of which teacher decoder layers were used
"""
_msg = "encoder_layers and decoder_layers cannot be both None-- you would just have an identical teacher."
assert (e is not None) or (d is not None), _msg
if isinstance(teacher, str):
AutoTokenizer.from_pretrained(teacher).save_pretrained(save_path) # purely for convenience
teacher = AutoModelForSeq2SeqLM.from_pretrained(teacher).eval()
else:
assert isinstance(teacher, PreTrainedModel), f"teacher must be a model or string got type {type(teacher)}"
init_kwargs = teacher.config.to_diff_dict()
try:
teacher_e, teacher_d = teacher.config.encoder_layers, teacher.config.decoder_layers
if e is None:
e = teacher_e
if d is None:
d = teacher_d
init_kwargs.update({"encoder_layers": e, "decoder_layers": d})
except AttributeError: # T5
teacher_e, teacher_d = teacher.config.num_layers, teacher.config.num_decoder_layers
if e is None:
e = teacher_e
if d is None:
d = teacher_d
init_kwargs.update({"num_layers": e, "num_decoder_layers": d})
# Kwargs to instantiate student: teacher kwargs with updated layer numbers + **extra_config_kwargs
init_kwargs.update(extra_config_kwargs)
# Copy weights
student_cfg = teacher.config_class(**init_kwargs)
student = AutoModelForSeq2SeqLM.from_config(student_cfg)
# Start by copying the full teacher state dict this will copy the first N teacher layers to the student.
info = student.load_state_dict(teacher.state_dict(), strict=False)
assert info.missing_keys == [], info.missing_keys # every student key should have a teacher keys.
if copy_first_teacher_layers: # Our copying is done. We just log and save
e_layers_to_copy, d_layers_to_copy = list(range(e)), list(range(d))
logger.info(
f"Copied encoder layers {e_layers_to_copy} and decoder layers {d_layers_to_copy}. Saving them to {save_path}"
)
student.save_pretrained(save_path)
return student, e_layers_to_copy, d_layers_to_copy
# Decide which layers of the teacher to copy. Not exactly alternating -- we try to keep first and last layer.
if e_layers_to_copy is None:
e_layers_to_copy: List[int] = pick_layers_to_copy(e, teacher_e)
if d_layers_to_copy is None:
d_layers_to_copy: List[int] = pick_layers_to_copy(d, teacher_d)
try:
copy_layers(teacher.model.encoder.layers, student.model.encoder.layers, e_layers_to_copy)
copy_layers(teacher.model.decoder.layers, student.model.decoder.layers, d_layers_to_copy)
except AttributeError: # For t5, student.model.encoder.layers is called student.encoder.block
copy_layers(teacher.encoder.block, student.encoder.block, e_layers_to_copy)
copy_layers(teacher.decoder.block, student.decoder.block, d_layers_to_copy)
logger.info(
f"Copied encoder layers {e_layers_to_copy} and decoder layers {d_layers_to_copy}. Saving them to {save_path}"
)
student.config.init_metadata = dict(
teacher_type=teacher.config.model_type,
copied_encoder_layers=e_layers_to_copy,
copied_decoder_layers=d_layers_to_copy,
)
student.save_pretrained(save_path)
# Save information about copying for easier reproducibility
return student, e_layers_to_copy, d_layers_to_copy
if __name__ == "__main__":
fire.Fire(create_student_by_copying_alternating_layers)