ColossalAI/examples/tutorial/sequence_parallel/loss_func/bert_loss.py

29 lines
946 B
Python

import torch
import torch.nn as nn
import torch.nn.functional as F
from colossalai.legacy.context import ParallelMode
from colossalai.legacy.core import global_context as gpc
class BertLoss(nn.Module):
def forward(self, lm_loss, sop_logits, loss_mask, sentence_order):
lm_loss_ = lm_loss.float()
loss_mask = loss_mask.float()
loss_mask_sum = loss_mask.sum()
lm_loss = torch.sum(lm_loss_.view(-1) * loss_mask.reshape(-1))
lm_loss /= loss_mask_sum
torch.distributed.all_reduce(lm_loss, group=gpc.get_group(ParallelMode.SEQUENCE))
if sop_logits is not None:
sop_loss = F.cross_entropy(sop_logits.view(-1, 2).float(), sentence_order.view(-1), ignore_index=-1)
sop_loss = sop_loss.float()
loss = lm_loss + sop_loss * gpc.get_world_size(ParallelMode.SEQUENCE)
else:
sop_loss = None
loss = lm_loss
return loss