convert : add --fuse-qkv flag to fuse Q/K/V into QKV during HF-to-GGUF conversion (#22780)

This commit is contained in:
PikaPikachu
2026-09-07 00:47:05 +08:00
committed by GitHub
parent 5fdfa62829
commit 465e49b9ce
20 changed files with 396 additions and 125 deletions
+91 -1
View File
@@ -130,7 +130,8 @@ class ModelBase:
sentence_transformers_dense_modules: bool = False,
target_model_dir: Path | None = None,
fuse_gate_up_exps: bool = False,
fp8_as_q8: bool = False):
fp8_as_q8: bool = False,
fuse_qkv: bool = False):
if type(self) is ModelBase or \
type(self) is TextModel or \
type(self) is MmprojModel:
@@ -153,6 +154,15 @@ class ModelBase:
self.fuse_gate_up_exps = fuse_gate_up_exps
self._gate_exp_buffer: dict[int, Tensor] = {}
self._up_exp_buffer: dict[int, Tensor] = {}
self.fuse_qkv = fuse_qkv
self._q_buffer: dict[int, Tensor] = {}
self._k_buffer: dict[int, Tensor] = {}
self._v_buffer: dict[int, Tensor] = {}
self._q_bias_buffer: dict[int, Tensor] = {}
self._k_bias_buffer: dict[int, Tensor] = {}
self._v_bias_buffer: dict[int, Tensor] = {}
self._fusable_qkv_weight_layers: set[int] = set()
self._fusable_qkv_bias_layers: set[int] = set()
self.hparams = ModelBase.load_hparams(self.dir_model, self.is_mistral_format) if hparams is None else hparams
self.model_tensors = self.index_tensors(remote_hf_model_id=remote_hf_model_id)
self.metadata_override = metadata_override
@@ -617,6 +627,43 @@ class ModelBase:
raise ValueError(f"Can not map tensor {name!r}")
return new_name
def prepare_qkv_fusion(self) -> None:
self._fusable_qkv_weight_layers.clear()
self._fusable_qkv_bias_layers.clear()
if not self.fuse_qkv or gguf.MODEL_TENSOR.ATTN_QKV not in gguf.MODEL_TENSORS[self.model_arch]:
return
qkv_types = {
gguf.MODEL_TENSOR.ATTN_Q,
gguf.MODEL_TENSOR.ATTN_K,
gguf.MODEL_TENSOR.ATTN_V,
}
weights: dict[int, set[gguf.MODEL_TENSOR]] = {}
biases: dict[int, set[gguf.MODEL_TENSOR]] = {}
for name in self.model_tensors:
mapped = self.tensor_map.get_type_and_name(name, try_suffixes=(".weight", ".bias"))
if mapped is None:
continue
tensor_type, new_name = mapped
if tensor_type not in qkv_types:
continue
bid = next((int(part) for part in new_name.split(".") if part.isdecimal()), None)
if bid is None:
continue
if new_name.endswith(".weight"):
weights.setdefault(bid, set()).add(tensor_type)
elif new_name.endswith(".bias"):
biases.setdefault(bid, set()).add(tensor_type)
for bid, weight_types in weights.items():
bias_types = biases.get(bid, set())
if weight_types == qkv_types and (not bias_types or bias_types == qkv_types):
self._fusable_qkv_weight_layers.add(bid)
if bias_types:
self._fusable_qkv_bias_layers.add(bid)
def set_gguf_parameters(self):
raise NotImplementedError("set_gguf_parameters() must be implemented in subclasses")
@@ -645,6 +692,40 @@ class ModelBase:
self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.FFN_UP_EXP, bid):
return []
# Handle Q/K/V tensor fusion if enabled
qkv_bid = next((int(part) for part in new_name.split(".") if part.isdecimal()), None) if self.fuse_qkv else None
if qkv_bid is not None:
is_bias = new_name.endswith('.bias')
suffix = '.bias' if is_bias else '.weight'
fusable_layers = self._fusable_qkv_bias_layers if is_bias else self._fusable_qkv_weight_layers
if qkv_bid not in fusable_layers:
return [(new_name, data_torch)]
buf_q = self._q_bias_buffer if is_bias else self._q_buffer
buf_k = self._k_bias_buffer if is_bias else self._k_buffer
buf_v = self._v_bias_buffer if is_bias else self._v_buffer
if self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_Q, qkv_bid, suffix):
buf_q[qkv_bid] = data_torch
elif self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_K, qkv_bid, suffix):
buf_k[qkv_bid] = data_torch
elif self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_V, qkv_bid, suffix):
buf_v[qkv_bid] = data_torch
if qkv_bid in buf_q and qkv_bid in buf_k and qkv_bid in buf_v:
q_data = buf_q.pop(qkv_bid)
k_data = buf_k.pop(qkv_bid)
v_data = buf_v.pop(qkv_bid)
fused_data = torch.cat([q_data, k_data, v_data], dim=0)
fused_name = self.format_tensor_name(gguf.MODEL_TENSOR.ATTN_QKV, qkv_bid, suffix=suffix)
logger.info(f"Fused Q, K, V {suffix[1:]} into QKV for layer {qkv_bid}")
return [(fused_name, fused_data)]
if self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_Q, qkv_bid, suffix) or \
self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_K, qkv_bid, suffix) or \
self.match_model_tensor_name(new_name, gguf.MODEL_TENSOR.ATTN_V, qkv_bid, suffix):
return []
return [(new_name, data_torch)]
def tensor_force_quant(self, name: str, new_name: str, bid: int | None, n_dims: int) -> gguf.GGMLQuantizationType | bool:
@@ -899,6 +980,8 @@ class ModelBase:
self.dequant_model()
self.prepare_qkv_fusion()
# Handle empty tensor_map for models with block_count=0 (like MobileNetV5)
if self.tensor_map.mapping:
max_name_len = max(len(s) for _, s in self.tensor_map.mapping.values()) + len(".weight,")
@@ -1027,6 +1110,13 @@ class ModelBase:
self.gguf_writer.add_tensor(new_name, data, raw_dtype=data_qtype)
qkv_buffers = (
self._q_buffer, self._k_buffer, self._v_buffer,
self._q_bias_buffer, self._k_bias_buffer, self._v_bias_buffer,
)
if any(qkv_buffers):
raise ValueError("QKV fusion did not consume all buffered tensors")
def set_type(self):
self.gguf_writer.add_type(gguf.GGUFType.MODEL)