| """Modified from https://github.com/THUDM/CogVideo/blob/3710a612d8760f5cdb1741befeebb65b9e0f2fe0/sat/sgm/modules/diffusionmodules/sigma_sampling.py |
| """ |
| import torch |
|
|
| class DiscreteSampling: |
| def __init__(self, num_idx, uniform_sampling=False, start_num_idx=0, sp_size=1): |
| self.num_idx = num_idx |
| self.start_num_idx = start_num_idx |
| self.uniform_sampling = uniform_sampling |
| self.is_distributed = torch.distributed.is_available() and torch.distributed.is_initialized() |
|
|
| if self.is_distributed and self.uniform_sampling: |
| world_size = torch.distributed.get_world_size() |
| self.rank = torch.distributed.get_rank() |
|
|
| i = 1 |
| while True: |
| if world_size % i != 0 or num_idx % (world_size // i) != 0: |
| i += 1 |
| else: |
| if i >= sp_size: |
| self.group_num = world_size // i |
| elif sp_size > world_size: |
| self.group_num = 1 |
| else: |
| self.group_num = world_size // sp_size |
| break |
| assert self.group_num > 0 |
| assert world_size % self.group_num == 0 |
| |
| self.group_width = world_size // self.group_num |
| self.sigma_interval = self.num_idx // self.group_num |
| print('rank=%d world_size=%d group_num=%d group_width=%d sigma_interval=%s' % ( |
| self.rank, world_size, self.group_num, |
| self.group_width, self.sigma_interval)) |
| |
| def __call__(self, n_samples, generator=None, device=None): |
| if self.is_distributed and self.uniform_sampling: |
| group_index = self.rank // self.group_width |
| idx = torch.randint( |
| self.start_num_idx + group_index * self.sigma_interval, |
| self.start_num_idx + (group_index + 1) * self.sigma_interval, |
| (n_samples,), |
| generator=generator, device=device, |
| ) |
| print('proc[%d] idx=%s' % (self.rank, idx)) |
| else: |
| idx = torch.randint( |
| self.start_num_idx, self.start_num_idx + self.num_idx, (n_samples,), |
| generator=generator, device=device, |
| ) |
| return idx |
