in src/transformers/models/mixtral/convert_mixtral_weights_to_hf.py [0:0]
def write_model(model_path, input_base_path, model_size, safe_serialization=True):
os.makedirs(model_path, exist_ok=True)
params = read_json(os.path.join(input_base_path, "params.json"))
num_shards = 1
# For some reason this is a string in the params.json
sliding_window = int(params["sliding_window"]) if "sliding_window" in params else None
n_layers = params["num_hidden_layers"]
n_heads = params["num_attention_heads"]
n_heads_per_shard = n_heads // num_shards
dim = params["hidden_size"]
dims_per_head = dim // n_heads
base = params.get("rope_theta", 10000.0)
max_position_embeddings = 4096 * 8
num_local_experts = params["num_local_experts"]
ffn_dim = params["intermediate_size"]
vocab_size = params["vocab_size"]
if "num_key_value_heads" in params:
num_key_value_heads = params["num_key_value_heads"] # for GQA / MQA
num_local_key_value_heads = num_key_value_heads // num_shards
key_value_dim = dims_per_head * num_local_key_value_heads
else: # compatibility with other checkpoints
num_key_value_heads = n_heads
num_local_key_value_heads = n_heads_per_shard
key_value_dim = dim
# permute for sliced rotary
def permute(w, n_heads=n_heads, dim1=dim, dim2=dim):
return w.view(n_heads, dim1 // n_heads // 2, 2, dim2).transpose(1, 2).reshape(dim1, dim2)
print(f"Fetching all parameters from the checkpoint at {input_base_path}.")
# Load weights
loaded = [
torch.load(os.path.join(input_base_path, f"consolidated.{i:02d}.pt"), map_location="cpu", weights_only=True)
for i in range(8)
]
merged_state_dict = {}
for state_dict in loaded:
merged_state_dict.update(state_dict)
state_dict = {}
for layer_i in range(n_layers):
# Sharded
# Note that attention.w{q,k,v,o}, feed_fordward.w[1,2,3], attention_norm.weight and ffn_norm.weight share
# the same storage object, saving attention_norm and ffn_norm will save other weights too, which is
# redundant as other weights will be stitched from multiple shards. To avoid that, they are cloned.
state_dict.update(
{
f"model.layers.{layer_i}.input_layernorm.weight": merged_state_dict[
f"layers.{layer_i}.attention_norm.weight"
].clone(),
f"model.layers.{layer_i}.post_attention_layernorm.weight": merged_state_dict[
f"layers.{layer_i}.ffn_norm.weight"
].clone(),
}
)
state_dict[f"model.layers.{layer_i}.self_attn.q_proj.weight"] = permute(
merged_state_dict[f"layers.{layer_i}.attention.wq.weight"]
.view(n_heads_per_shard, dims_per_head, dim)
.reshape(dim, dim)
)
state_dict[f"model.layers.{layer_i}.self_attn.k_proj.weight"] = permute(
merged_state_dict[f"layers.{layer_i}.attention.wk.weight"]
.view(num_local_key_value_heads, dims_per_head, dim)
.reshape(key_value_dim, dim),
num_key_value_heads,
key_value_dim,
dim,
)
state_dict[f"model.layers.{layer_i}.self_attn.v_proj.weight"] = (
merged_state_dict[f"layers.{layer_i}.attention.wv.weight"]
.view(num_local_key_value_heads, dims_per_head, dim)
.reshape(key_value_dim, dim)
)
state_dict[f"model.layers.{layer_i}.self_attn.o_proj.weight"] = merged_state_dict[
f"layers.{layer_i}.attention.wo.weight"
]
w1 = merged_state_dict[f"layers.{layer_i}.block_sparse_moe.w1"]
w2 = merged_state_dict[f"layers.{layer_i}.block_sparse_moe.w2"]
w3 = merged_state_dict[f"layers.{layer_i}.block_sparse_moe.w3"]
experts_w1 = [
w1[ffn_dim * expert_idx : ffn_dim * (expert_idx + 1), :].clone(memory_format=torch.contiguous_format)
for expert_idx in range(num_local_experts)
]
for idx, expert_block in enumerate(experts_w1):
expert_key = f"model.layers.{layer_i}.block_sparse_moe.experts.{idx}.w1"
state_dict[expert_key + ".weight"] = expert_block.clone()
experts_w2 = [
w2[ffn_dim * expert_idx : ffn_dim * (expert_idx + 1), :].clone(memory_format=torch.contiguous_format)
for expert_idx in range(num_local_experts)
]
for idx, expert_block in enumerate(experts_w2):
expert_key = f"model.layers.{layer_i}.block_sparse_moe.experts.{idx}.w2"
state_dict[expert_key + ".weight"] = expert_block.T.clone(memory_format=torch.contiguous_format)
experts_w3 = [
w3[ffn_dim * expert_idx : ffn_dim * (expert_idx + 1), :].clone(memory_format=torch.contiguous_format)
for expert_idx in range(num_local_experts)
]
for idx, expert_block in enumerate(experts_w3):
expert_key = f"model.layers.{layer_i}.block_sparse_moe.experts.{idx}.w3"
state_dict[expert_key + ".weight"] = expert_block.clone()
state_dict[f"model.layers.{layer_i}.block_sparse_moe.gate.weight"] = merged_state_dict[
f"layers.{layer_i}.block_sparse_moe.gate.weight"
]
state_dict.update(
{
"model.norm.weight": merged_state_dict["norm.weight"],
"model.embed_tokens.weight": merged_state_dict["tok_embeddings.weight"],
"lm_head.weight": merged_state_dict["output.weight"],
}
)
config = MixtralConfig(
hidden_size=dim,
intermediate_size=ffn_dim,
num_attention_heads=params["num_attention_heads"],
num_hidden_layers=params["num_hidden_layers"],
rms_norm_eps=params["rms_norm_eps"],
num_key_value_heads=num_key_value_heads,
vocab_size=vocab_size,
rope_theta=base,
max_position_embeddings=max_position_embeddings,
sliding_window=sliding_window,
num_local_experts=num_local_experts,
)
print("Loading the checkpoint in a Mixtral model.")
with torch.device("meta"):
model = MixtralForCausalLM(config)
# Avoid saving this as part of the config.
del model.config._name_or_path
model.config.torch_dtype = torch.float16
print("Saving in the Transformers format.")
model.load_state_dict(state_dict, strict=True, assign=True)
for n, p in model.named_parameters():
assert p.device.type != "meta", f"{n} has not been loaded!"
model.save_pretrained(model_path, safe_serialization=safe_serialization)