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petals/src/petals/models/bloom/block.py

33 lines
1.4 KiB
Python

Add LLaMA support (#323) This PR: 1. **Abolishes the model conversion procedure.** Now, models are downloaded directly from original repositories like https://huggingface.co/bigscience/bloom. Servers download only shards with blocks to be hosted, and clients download only shards with input/output embeddings and layernorms. - BLOOM is loaded from `bigscience/bloom`, but we use the DHT prefix `bigscience/bloom-petals` for backward compatibility. Same with smaller BLOOMs and BLOOMZ. - LLaMA can be loaded from any repo like `username/llama-65b-hf`, but we use the DHT prefix `llama-65b-hf` (without the username) to accomodate blocks from different repos (there're a few of them with minor differences, such as `Llama` vs. `LLaMA` in the class name). 2. **Refactors the client to generalize it for multiple models.** Now, we have `petals.models` packages that contain model-specific code (e.g. `petals.models.bloom`, `petals.models.llama`). General code (e.g. CPU-efficient LM head, p-tuning) is kept in `petals.client`. 3. **Introduces** `WrappedLlamaBlock`, `DistributedLlamaConfig`, `DistributedLlamaForCausalLM`, `DistributedLlamaForSequenceClassification`, and `DistributedLlamaModel` compatible with Petals functionality (p-tuning, adapters, etc.). 4. **Introduces** `AutoDistributedConfig` that automatically chooses the correct config class (`DistributedLlamaConfig` or `DistributedBloomConfig`). The refactored configs contain all model-specific info for both clients and servers. Upgrade instructions: - Remove disk caches for blocks in old (converted) format to save disk space. That is, remove `~/.cache/petals/model--bigscience--bloom-petals` and `~/.cache/petals/model--bigscience--bloomz-petals` directories (if present).
11 months ago
"""
Bloom intermediate layer
Based on https://github.com/huggingface/transformers/commit/ca2a55e9dfb245527b5e1c954fec6ffbb7aef07b
See commit history for authorship.
"""
from typing import Optional, Tuple
import torch
from transformers.models.bloom.modeling_bloom import BloomBlock, BloomModel, build_alibi_tensor
class WrappedBloomBlock(BloomBlock):
def forward(
self,
hidden_states: torch.Tensor,
*args,
attention_mask: Optional[torch.Tensor] = None,
alibi: Optional[torch.Tensor] = None,
layer_past: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
**kwargs
):
assert attention_mask is None, "Non-causal attention masks are not supported yet"
batch_size, seq_length = hidden_states.shape[:2]
past_length = 0 if layer_past is None else layer_past[0].shape[-1]
seq_length_with_past = seq_length + past_length
attention_mask = torch.ones((batch_size, seq_length_with_past), device=hidden_states.device)
if alibi is None:
alibi = build_alibi_tensor(attention_mask, num_heads=self.num_heads, dtype=hidden_states.dtype)
attention_mask = BloomModel._prepare_attn_mask(None, attention_mask, (batch_size, seq_length), past_length)
return super().forward(
hidden_states, *args, attention_mask=attention_mask, alibi=alibi, layer_past=layer_past, **kwargs
)