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| from typing import Optional |
|
|
| import numpy as np |
|
|
| from cosmos_transfer1.utils import distributed, log |
|
|
|
|
| class TeroPolyScheduler: |
| def __init__( |
| self, |
| total_Mimg: int, |
| batch_size: int, |
| ref_Mimg: Optional[int] = None, |
| ref_batches: float = 70e3 / 1024, |
| max_lr_ratio: Optional[float] = 1.0, |
| min_lr_ratio: Optional[float] = None, |
| rampup_Mimg: float = 0, |
| rampdown_Mimg: int = 0, |
| verbosity_interval: int = 0, |
| formula: str = "poly", |
| poly_exp: float = 0.5, |
| ): |
| self.total_Mimg = total_Mimg |
| self.batch_size = batch_size * distributed.get_world_size() |
| self.ref_Mimg = ref_Mimg or ref_batches * batch_size / 1e6 |
| self.ref_batches = ref_batches |
| self.max_lr_ratio = max_lr_ratio |
| self.min_lr_ratio = min_lr_ratio |
| self.rampup_Mimg = rampup_Mimg |
| self.rampdown_Mimg = rampdown_Mimg |
| self.verbosity_interval = verbosity_interval |
| self.formula = formula |
| self.poly_exp = poly_exp |
|
|
| self._model = None |
|
|
| @property |
| def model(self): |
| return self._model |
|
|
| @model.setter |
| def model(self, model): |
| self._model = model |
|
|
| def schedule(self, n, **kwargs): |
| cur_Mimg = getattr(self.model, "sample_counter", 0) / 1e6 |
|
|
| if self.formula == "constant": |
| lr = 1.0 |
| elif self.formula == "poly": |
| lr = max(cur_Mimg / self.ref_Mimg, 1e-8) ** -self.poly_exp |
| else: |
| raise ValueError(f'Invalid learning rate formula "{self.formula}"') |
|
|
| if self.max_lr_ratio is not None: |
| lr = min(lr, self.max_lr_ratio) |
| if self.min_lr_ratio is not None: |
| lr = max(lr, self.min_lr_ratio) |
|
|
| if self.rampup_Mimg > 0 and cur_Mimg < self.rampup_Mimg: |
| lr *= cur_Mimg / self.rampup_Mimg |
| if self.rampdown_Mimg > 0 and cur_Mimg > self.total_Mimg - self.rampdown_Mimg: |
| lr *= (self.total_Mimg - cur_Mimg) / self.rampdown_Mimg |
|
|
| return lr |
|
|
| def __call__(self, n, **kwargs): |
| return self.schedule(n, **kwargs) |
|
|
|
|
| class LambdaWarmUpCosineScheduler: |
| """ |
| A learning rate scheduler that combines warm-up with a cosine decay schedule for multiple cycles. |
| It supports different configurations for each cycle, including the number of warm-up steps, minimum |
| and maximum scaling factors for the learning rate. |
| |
| The scheduler is intended to be used with a base learning rate of 1.0, where the actual learning |
| rate at any step is the base learning rate multiplied by the scaling factor computed by the scheduler. |
| |
| Parameters: |
| warm_up_steps (list[int]): List of integers where each element represents the number of warm-up |
| steps for the corresponding cycle. |
| f_min (list[float]): List of the minimum scaling factors for each cycle after warm-up. |
| f_max (list[float]): List of the maximum scaling factors at the start and end of each cosine cycle. |
| f_start (list[float]): List of starting scaling factors for each warm-up phase. |
| cycle_lengths (list[int]): List of the total lengths of each cycle, including warm-up steps. |
| verbosity_interval (int, optional): Interval of training steps at which to print current step and |
| scaling factor information. Set to 0 by default to disable verbosity. |
| |
| Examples: |
| >>> scheduler = LambdaWarmUpCosineScheduler2( |
| warm_up_steps=[10, 10], |
| f_min=[0.1, 0.1], |
| f_max=[1.0, 1.0], |
| f_start=[0.01, 0.01], |
| cycle_lengths=[50, 50], |
| verbosity_interval=10) |
| >>> for step in range(100): |
| >>> lr_multiplier = scheduler(step) |
| >>> print(f"Step {step}: LR Multiplier = {lr_multiplier}") |
| """ |
|
|
| def __init__(self, warm_up_steps, f_min, f_max, f_start, cycle_lengths, verbosity_interval=0): |
| assert len(warm_up_steps) == len(f_min) == len(f_max) == len(f_start) == len(cycle_lengths) |
| self.lr_warm_up_steps = warm_up_steps |
| self.f_start = f_start |
| self.f_min = f_min |
| self.f_max = f_max |
| self.cycle_lengths = cycle_lengths |
| self.cum_cycles = np.cumsum([0] + list(self.cycle_lengths)) |
| self.last_f = 0.0 |
| self.verbosity_interval = verbosity_interval |
|
|
| def find_in_interval(self, n): |
| interval = 0 |
| for cl in self.cum_cycles[1:]: |
| if n <= cl: |
| return interval |
| interval += 1 |
|
|
| def schedule(self, n, **kwargs): |
| cycle = self.find_in_interval(n) |
| n = n - self.cum_cycles[cycle] |
| if self.verbosity_interval > 0: |
| if n % self.verbosity_interval == 0: |
| log.info(f"current step: {n}, recent lr-multiplier: {self.last_f}, " f"current cycle {cycle}") |
| if n < self.lr_warm_up_steps[cycle]: |
| f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle] |
| self.last_f = f |
| return f |
| else: |
| t = (n - self.lr_warm_up_steps[cycle]) / (self.cycle_lengths[cycle] - self.lr_warm_up_steps[cycle]) |
| t = min(t, 1.0) |
| f = self.f_min[cycle] + 0.5 * (self.f_max[cycle] - self.f_min[cycle]) * (1 + np.cos(t * np.pi)) |
| self.last_f = f |
| return f |
|
|
| def __call__(self, n, **kwargs): |
| return self.schedule(n, **kwargs) |
|
|
|
|
| class LambdaLinearScheduler(LambdaWarmUpCosineScheduler): |
| """ |
| Linear instead of cosine decay for the main part of the cycle. |
| """ |
|
|
| def schedule(self, n, **kwargs): |
| cycle = self.find_in_interval(n) |
| n = n - self.cum_cycles[cycle] |
| if self.verbosity_interval > 0: |
| if n % self.verbosity_interval == 0: |
| log.info(f"current step: {n}, recent lr-multiplier: {self.last_f}, " f"current cycle {cycle}") |
|
|
| if n < self.lr_warm_up_steps[cycle]: |
| f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle] |
| self.last_f = f |
| return f |
| else: |
| f = self.f_min[cycle] + (self.f_max[cycle] - self.f_min[cycle]) * (self.cycle_lengths[cycle] - n) / ( |
| self.cycle_lengths[cycle] - self.lr_warm_up_steps[cycle] |
| ) |
| self.last_f = f |
| return f |
|
|