llama-stack/llama_stack/models/llama/llama4/ffn.py
Ashwin Bharambe 530d4bdfe1
refactor: move all llama code to models/llama out of meta reference (#1887)
# What does this PR do?

Move around bits. This makes the copies from llama-models _much_ easier
to maintain and ensures we don't entangle meta-reference specific
tidbits into llama-models code even by accident.

Also, kills the meta-reference-quantized-gpu distro and rolls
quantization deps into meta-reference-gpu.

## Test Plan

```
LLAMA_MODELS_DEBUG=1 \
  with-proxy llama stack run meta-reference-gpu \
  --env INFERENCE_MODEL=meta-llama/Llama-4-Scout-17B-16E-Instruct \
   --env INFERENCE_CHECKPOINT_DIR=<DIR> \
   --env MODEL_PARALLEL_SIZE=4 \
   --env QUANTIZATION_TYPE=fp8_mixed
```

Start a server with and without quantization. Point integration tests to
it using:

```
pytest -s -v  tests/integration/inference/test_text_inference.py \
   --stack-config http://localhost:8321 --text-model meta-llama/Llama-4-Scout-17B-16E-Instruct
```
2025-04-07 15:03:58 -07:00

58 lines
2.1 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# top-level folder for each specific model found within the models/ directory at
# the top-level of this source tree.
from typing import Any, Dict, List
from fairscale.nn.model_parallel.layers import ColumnParallelLinear, RowParallelLinear
from fairscale.nn.model_parallel.mappings import reduce_from_model_parallel_region
from torch import nn
from torch.nn import functional as F
class FeedForward(nn.Module):
def __init__(
self,
dim: int,
hidden_dim: int,
do_reduce: bool = True,
):
super().__init__()
self.do_reduce = do_reduce
self.w1 = ColumnParallelLinear(dim, hidden_dim, bias=False, gather_output=False, init_method=lambda x: x)
self.w2 = RowParallelLinear(hidden_dim, dim, bias=False, input_is_parallel=True, init_method=lambda x: x)
self.w3 = ColumnParallelLinear(dim, hidden_dim, bias=False, gather_output=False, init_method=lambda x: x)
self._register_load_state_dict_pre_hook(self.load_hook)
def load_hook(
self,
state_dict: Dict[str, Any],
prefix: str,
local_metadata: Dict[str, Any],
strict: bool,
missing_keys: List[str],
unexpected_keys: List[str],
error_msgs: List[str],
) -> None:
if prefix + "mlp.fc1_weight" in state_dict:
w1, w3 = state_dict.pop(prefix + "mlp.fc1_weight").chunk(2, dim=0)
state_dict[prefix + "w1.weight"] = w1
state_dict[prefix + "w3.weight"] = w3
state_dict[prefix + "w2.weight"] = state_dict.pop(prefix + "mlp.fc2_weight")
def forward(self, x):
x = F.silu(F.linear(x, self.w1.weight)) * F.linear(x, self.w3.weight)
out = F.linear(x, self.w2.weight)
if self.do_reduce:
return reduce_from_model_parallel_region(out)
return out