# coding=utf-8 from functools import partial from typing import Callable, List, Optional, Tuple, Union import torch import torch.nn.functional as F from torch import nn from transformers.cache_utils import Cache, DynamicCache, SlidingWindowCache, StaticCache from transformers.generation import GenerationMixin from transformers.modeling_attn_mask_utils import AttentionMaskConverter from transformers.modeling_flash_attention_utils import FlashAttentionKwargs from transformers.modeling_outputs import ( MoeCausalLMOutputWithPast, MoeModelOutputWithPast ) from transformers.modeling_rope_utils import ROPE_INIT_FUNCTIONS, dynamic_rope_update from transformers.modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel from transformers.processing_utils import Unpack from transformers.utils import LossKwargs, can_return_tuple, is_torch_flex_attn_available, logging from .configuration_smallthinker import SmallthinkerConfig if is_torch_flex_attn_available(): from torch.nn.attention.flex_attention import BlockMask from transformers.integrations.flex_attention import make_flex_block_causal_mask logger = logging.get_logger(__name__) class SmallthinkerHierarchicalMLP(nn.Module): def __init__(self, config: SmallthinkerConfig): super().__init__() self.config = config self.hidden_dim = config.hidden_size self.ffn_dim = config.moe_ffn_hidden_size self.moe_enable_secondary_experts = config.moe_enable_secondary_experts if self.moe_enable_secondary_experts: self.num_secondary_experts = config.moe_num_secondary_experts self.secondary_expert_size = config.moe_secondary_expert_size self.secondary_gate = nn.Linear(self.hidden_dim, self.num_secondary_experts, bias=False) self.up = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False) self.gate = nn.Linear(self.hidden_dim, self.ffn_dim, bias=False) self.down = nn.Linear(self.ffn_dim, self.hidden_dim, bias=False) def forward(self, secondary_gate_input: torch.Tensor, hidden_states: torch.Tensor): if self.moe_enable_secondary_experts: secondary_gate_logits = F.sigmoid(self.secondary_gate(secondary_gate_input)) > 0.5 secondary_gate_mask = secondary_gate_logits.unsqueeze(-1) current_hidden_states = self.up(hidden_states) * F.relu(self.gate(hidden_states)) activated_output = current_hidden_states batch_size, intermediate_size = activated_output.shape if self.moe_enable_secondary_experts: num_groups = intermediate_size // self.secondary_expert_size activated_output = activated_output.view(batch_size, num_groups, self.secondary_expert_size) output = activated_output * secondary_gate_mask else: output = activated_output current_hidden_states = output.view(batch_size, -1) current_hidden_states = self.down(current_hidden_states) return current_hidden_states class SmallthinkerMoeBlock(nn.Module): def __init__(self, config: SmallthinkerConfig): super().__init__() self.hidden_dim = config.hidden_size self.num_primary_experts = config.moe_num_primary_experts self.enable_early_router = config.moe_enable_early_router self.moe_primary_router_apply_softmax = config.moe_primary_router_apply_softmax self.num_active_primary_experts = config.moe_num_active_primary_experts self.primary_router = nn.Linear(self.hidden_dim, self.num_primary_experts, bias=False) self.experts = nn.ModuleList([SmallthinkerHierarchicalMLP(config) for _ in range(self.num_primary_experts)]) def forward(self, router_input: torch.Tensor, hidden_states: torch.Tensor) -> torch.Tensor: batch_size, sequence_length, hidden_dim = hidden_states.shape # Flatten the tokens into (bs * sl, hidden_dim) hidden_states = hidden_states.view(-1, hidden_dim) router_input = router_input.view(-1, hidden_dim) # Primary router logits: (bs * sl, n_experts) if self.enable_early_router: router_logits = self.primary_router(router_input) else: router_logits = self.primary_router(hidden_states) router_logits, selected_experts = torch.topk(router_logits, self.num_active_primary_experts, dim=-1) if self.moe_primary_router_apply_softmax: routing_weights = F.softmax(router_logits, dim=1, dtype=torch.float) else: routing_weights = F.sigmoid(router_logits) routing_weights /= routing_weights.sum(dim=-1, keepdim=True) routing_weights = routing_weights.to(hidden_states.dtype) # Prepare the final tensor final_hidden_states = torch.zeros( (batch_size * sequence_length, hidden_dim), dtype=hidden_states.dtype, device=hidden_states.device ) # One hot encode the selected experts to create an expert mask # this will be used to easily index which expert is going to be sollicitated expert_mask = torch.nn.functional.one_hot(selected_experts, num_classes=self.num_primary_experts).permute(2, 1, 0) expert_hitted = (expert_mask.sum(dim=(-1, -2)) > 0).nonzero(as_tuple=True)[0].tolist() for expert_idx in expert_hitted: expert_layer = self.experts[expert_idx] idx, top_x = torch.where(expert_mask[expert_idx]) # Index the correct hidden states and compute the expert hidden state for # the current expert. We need to make sure to multiply the output hidden # states by `routing_weights` on the corresponding tokens (top-1 and top-2) # current_state = hidden_states[None, top_x].reshape(-1, hidden_dim) # current_router_input = router_input[None, top_x].reshape(-1, hidden_dim) current_state = hidden_states[top_x].reshape(-1, hidden_dim) current_router_input = router_input[top_x].reshape(-1, hidden_dim) current_hidden_states = expert_layer(current_router_input, current_state) * routing_weights[top_x, idx, None] # However `index_add_` only support torch tensors for indexing so we'll use the `top_x` tensor here. final_hidden_states.index_add_(0, top_x, current_hidden_states.to(hidden_states.dtype)) final_hidden_states = final_hidden_states.reshape(batch_size, sequence_length, hidden_dim) return final_hidden_states, router_logits class SmallthinkerDenseMlpBlock(nn.Module): def __init__(self, config: SmallthinkerConfig): super().__init__() hidden_dim = config.hidden_size ffn_dim = config.dense_ffn_hidden_size self.up = nn.Linear(hidden_dim, ffn_dim, bias=False) self.gate = nn.Linear(hidden_dim, ffn_dim, bias=False) self.down = nn.Linear(ffn_dim, hidden_dim, bias=False) # Offer unified interface for SmallthinkerMoeBlock and SmallthinkerDenseMlpBlock, though router_input is not used here def forward(self, router_input: torch.Tensor, hidden_states: torch.Tensor) -> torch.Tensor: current_hidden_states = self.up(hidden_states) * F.relu(self.gate(hidden_states)) current_hidden_states = self.down(current_hidden_states) return current_hidden_states, None class SmallthinkerRMSNorm(nn.Module): def __init__(self, hidden_size, eps=1e-6): """ SmallthinkerRMSNorm is equivalent to T5LayerNorm """ super().__init__() self.hidden_size = hidden_size self.weight = nn.Parameter(torch.ones(hidden_size)) self.variance_epsilon = eps def forward(self, hidden_states): input_dtype = hidden_states.dtype hidden_states = hidden_states.to(torch.float32) variance = hidden_states.pow(2).mean(-1, keepdim=True) hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon) return self.weight * hidden_states.to(input_dtype) def extra_repr(self): return f"{tuple(self.weight.shape)}, eps={self.variance_epsilon}" def rotate_half(x): """Rotates half the hidden dims of the input.""" x1 = x[..., : x.shape[-1] // 2] x2 = x[..., x.shape[-1] // 2 :] return torch.cat((-x2, x1), dim=-1) def apply_rotary_pos_emb(q, k, cos, sin, position_ids=None, unsqueeze_dim=1): """Applies Rotary Position Embedding to the query and key tensors. Args: q (`torch.Tensor`): The query tensor. k (`torch.Tensor`): The key tensor. cos (`torch.Tensor`): The cosine part of the rotary embedding. sin (`torch.Tensor`): The sine part of the rotary embedding. position_ids (`torch.Tensor`, *optional*): Deprecated and unused. unsqueeze_dim (`int`, *optional*, defaults to 1): The 'unsqueeze_dim' argument specifies the dimension along which to unsqueeze cos[position_ids] and sin[position_ids] so that they can be properly broadcasted to the dimensions of q and k. For example, note that cos[position_ids] and sin[position_ids] have the shape [batch_size, seq_len, head_dim]. Then, if q and k have the shape [batch_size, heads, seq_len, head_dim], then setting unsqueeze_dim=1 makes cos[position_ids] and sin[position_ids] broadcastable to the shapes of q and k. Similarly, if q and k have the shape [batch_size, seq_len, heads, head_dim], then set unsqueeze_dim=2. Returns: `tuple(torch.Tensor)` comprising of the query and key tensors rotated using the Rotary Position Embedding. """ cos = cos.unsqueeze(unsqueeze_dim) sin = sin.unsqueeze(unsqueeze_dim) q_embed = (q * cos) + (rotate_half(q) * sin) k_embed = (k * cos) + (rotate_half(k) * sin) return q_embed, k_embed def repeat_kv(hidden_states: torch.Tensor, n_rep: int) -> torch.Tensor: """ This is the equivalent of torch.repeat_interleave(x, dim=1, repeats=n_rep). The hidden states go from (batch, num_key_value_heads, seqlen, head_dim) to (batch, num_attention_heads, seqlen, head_dim) """ batch, num_key_value_heads, slen, head_dim = hidden_states.shape if n_rep == 1: return hidden_states hidden_states = hidden_states[:, :, None, :, :].expand(batch, num_key_value_heads, n_rep, slen, head_dim) return hidden_states.reshape(batch, num_key_value_heads * n_rep, slen, head_dim) def eager_attention_forward( module: nn.Module, query: torch.Tensor, key: torch.Tensor, value: torch.Tensor, attention_mask: Optional[torch.Tensor], scaling: float, dropout: float = 0.0, **kwargs, ): key_states = repeat_kv(key, module.num_key_value_groups) value_states = repeat_kv(value, module.num_key_value_groups) attn_weights = torch.matmul(query, key_states.transpose(2, 3)) * scaling if attention_mask is not None: causal_mask = attention_mask[:, :, :, : key_states.shape[-2]] attn_weights = attn_weights + causal_mask attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query.dtype) attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training) attn_output = torch.matmul(attn_weights, value_states) attn_output = attn_output.transpose(1, 2).contiguous() return attn_output, attn_weights class SmallthinkerAttention(nn.Module): def __init__(self, config: SmallthinkerConfig, layer_idx: int): super().__init__() self.config = config self.layer_idx = layer_idx # For KVCache management self.head_dim = config.head_dim self.num_attention_heads = config.num_attention_heads self.num_key_value_heads = config.num_key_value_heads self.num_key_value_groups = config.num_attention_heads // config.num_key_value_heads self.scaling = self.head_dim**-0.5 self.is_causal = True self.q_proj = nn.Linear(config.hidden_size, config.num_attention_heads * self.head_dim, bias=False) self.k_proj = nn.Linear(config.hidden_size, config.num_key_value_heads * self.head_dim, bias=False) self.v_proj = nn.Linear(config.hidden_size, config.num_key_value_heads * self.head_dim, bias=False) self.o_proj = nn.Linear(config.num_attention_heads * self.head_dim, config.hidden_size, bias=False) self.sliding_window = config.sliding_window_size if config.sliding_window_layout[layer_idx] else None self.use_qk_norm = config.use_qk_norm def forward( self, hidden_states: torch.Tensor, position_embeddings: Tuple[torch.Tensor, torch.Tensor], attention_mask: Optional[torch.Tensor], past_key_value: Optional[Cache] = None, cache_position: Optional[torch.LongTensor] = None, **kwargs: Unpack[FlashAttentionKwargs], ) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]: if self.use_qk_norm: raise NotImplementedError("use_qk_norm is not implemented yet") input_shape = hidden_states.shape[:-1] hidden_shape = (*input_shape, -1, self.head_dim) query_states = self.q_proj(hidden_states).view(hidden_shape).transpose(1, 2) key_states = self.k_proj(hidden_states).view(hidden_shape).transpose(1, 2) value_states = self.v_proj(hidden_states).view(hidden_shape).transpose(1, 2) if position_embeddings: cos, sin = position_embeddings query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin) else: cos, sin = None, None if past_key_value is not None: # sin and cos are specific to RoPE models; cache_position needed for the static cache cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position} key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs) attention_interface: Callable = eager_attention_forward if self.config._attn_implementation == "sdpa": raise NotImplementedError("SDPA impl is buggy for now. NEVER TRY TO USE IT.") if self.config._attn_implementation != "eager": if self.config._attn_implementation == "sdpa" and kwargs.get("output_attentions", False): logger.warning_once( "`torch.nn.functional.scaled_dot_product_attention` does not support `output_attentions=True`. Falling back to " 'eager attention. This warning can be removed using the argument `attn_implementation="eager"` when loading the model.' ) else: attention_interface = ALL_ATTENTION_FUNCTIONS[self.config._attn_implementation] attn_output, attn_weights = attention_interface( self, query_states, key_states, value_states, attention_mask, dropout=0.0, scaling=self.scaling, sliding_window=self.sliding_window, # main diff with Llama **kwargs, ) attn_output = attn_output.reshape(*input_shape, -1).contiguous() attn_output = self.o_proj(attn_output) return attn_output, attn_weights class SmallthinkerDecoderLayer(nn.Module): def __init__(self, config: SmallthinkerConfig, layer_idx: int): super().__init__() self.hidden_size = config.hidden_size self.self_attn = SmallthinkerAttention(config, layer_idx) self.block_sparse_moe = SmallthinkerMoeBlock(config) if config.moe_layer_layout[layer_idx] else SmallthinkerDenseMlpBlock(config) self.input_layernorm = SmallthinkerRMSNorm(config.hidden_size, eps=config.rms_norm_eps) self.post_attention_layernorm = SmallthinkerRMSNorm(config.hidden_size, eps=config.rms_norm_eps) def forward( self, hidden_states: torch.Tensor, attention_mask: Optional[torch.Tensor] = None, position_ids: Optional[torch.LongTensor] = None, past_key_value: Optional[Tuple[torch.Tensor]] = None, output_attentions: Optional[bool] = False, output_router_logits: Optional[bool] = False, use_cache: Optional[bool] = False, cache_position: Optional[torch.LongTensor] = None, position_embeddings: Optional[Tuple[torch.Tensor, torch.Tensor]] = None, # necessary, but kept here for BC **kwargs: Unpack[FlashAttentionKwargs], ) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]: """ Args: hidden_states (`torch.FloatTensor`): input to the layer of shape `(batch, seq_len, embed_dim)` attention_mask (`torch.FloatTensor`, *optional*): attention mask of size `(batch, sequence_length)` where padding elements are indicated by 0. past_key_value (`Tuple(torch.FloatTensor)`, *optional*): cached past key and value projection states output_attentions (`bool`, *optional*): Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned tensors for more detail. output_router_logits (`bool`, *optional*): Whether or not to return the logits of all the routers. They are useful for computing the router loss, and should not be returned during inference. use_cache (`bool`, *optional*): If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see `past_key_values`). cache_position (`torch.LongTensor` of shape `(sequence_length)`, *optional*): Indices depicting the position of the input sequence tokens in the sequence. kwargs (`dict`, *optional*): Arbitrary kwargs to be ignored, used for FSDP and other methods that injects code into the model """ # print(f"hidden states, shape {hidden_states.shape}: {hidden_states}") # debug print residual = hidden_states router_input = hidden_states hidden_states = self.input_layernorm(hidden_states) # Self Attention hidden_states, self_attn_weights = self.self_attn( hidden_states=hidden_states, position_embeddings=position_embeddings, attention_mask=attention_mask, position_ids=position_ids, past_key_value=past_key_value, output_attentions=output_attentions, use_cache=use_cache, cache_position=cache_position, **kwargs, ) hidden_states = residual + hidden_states # Fully Connected residual = hidden_states hidden_states = self.post_attention_layernorm(hidden_states) hidden_states, router_logits = self.block_sparse_moe(router_input, hidden_states) hidden_states = residual + hidden_states # SYNC after_moe_residual_value=hidden_states outputs = (hidden_states,) if output_attentions: outputs += (self_attn_weights,) if output_router_logits: outputs += (router_logits,) return outputs class SmallthinkerRotaryEmbedding(nn.Module): def __init__(self, config: SmallthinkerConfig, device=None): super().__init__() # BC: "rope_type" was originally "type" if hasattr(config, "rope_scaling") and config.rope_scaling is not None: self.rope_type = config.rope_scaling.get("rope_type", config.rope_scaling.get("type")) else: self.rope_type = "default" self.max_seq_len_cached = config.max_position_embeddings self.original_max_seq_len = config.max_position_embeddings self.config = config self.rope_init_fn = ROPE_INIT_FUNCTIONS[self.rope_type] inv_freq, self.attention_scaling = self.rope_init_fn(self.config, device) self.register_buffer("inv_freq", inv_freq, persistent=False) self.original_inv_freq = self.inv_freq @torch.no_grad() @dynamic_rope_update # power user: used with advanced RoPE types (e.g. dynamic rope) def forward(self, x, position_ids): inv_freq_expanded = self.inv_freq[None, :, None].float().expand(position_ids.shape[0], -1, 1).to(x.device) position_ids_expanded = position_ids[:, None, :].float() device_type = x.device.type if isinstance(x.device.type, str) and x.device.type != "mps" else "cpu" with torch.autocast(device_type=device_type, enabled=False): # Force float32 freqs = (inv_freq_expanded.float() @ position_ids_expanded.float()).transpose(1, 2) emb = torch.cat((freqs, freqs), dim=-1) cos = emb.cos() * self.attention_scaling sin = emb.sin() * self.attention_scaling return cos.to(dtype=x.dtype), sin.to(dtype=x.dtype) class SmallthinkerPreTrainedModel(PreTrainedModel): config_class = SmallthinkerConfig base_model_prefix = "model" supports_gradient_checkpointing = True _no_split_modules = ["SmallthinkerDecoderLayer"] _skip_keys_device_placement = ["past_key_values"] _supports_flash_attn_2 = True _supports_sdpa = True _supports_flex_attn = True _supports_cache_class = True _supports_quantized_cache = True _supports_static_cache = False # MoE models don't work with torch.compile (`torch.where(condition)` not supported) _supports_attention_backend = True def _init_weights(self, module): std = self.config.initializer_range if isinstance(module, nn.Linear): module.weight.data.normal_(mean=0.0, std=std) if module.bias is not None: module.bias.data.zero_() elif isinstance(module, nn.Embedding): module.weight.data.normal_(mean=0.0, std=std) if module.padding_idx is not None: module.weight.data[module.padding_idx].zero_() elif isinstance(module, SmallthinkerRMSNorm): module.weight.data.fill_(1.0) # @auto_docstring class SmallthinkerModel(SmallthinkerPreTrainedModel): def __init__(self, config: SmallthinkerConfig): super().__init__(config) self.padding_idx = config.pad_token_id self.vocab_size = config.vocab_size self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx) self.layers = nn.ModuleList( [SmallthinkerDecoderLayer(config, layer_idx) for layer_idx in range(config.num_hidden_layers)] ) self.norm = SmallthinkerRMSNorm(config.hidden_size, eps=config.rms_norm_eps) self.rotary_emb = SmallthinkerRotaryEmbedding(config=config) self.gradient_checkpointing = False self.rope_layout = config.rope_layout # Initialize weights and apply final processing self.post_init() def get_input_embeddings(self): return self.embed_tokens def set_input_embeddings(self, value): self.embed_tokens = value @can_return_tuple # @auto_docstring def forward( self, input_ids: Optional[torch.LongTensor] = None, attention_mask: Optional[torch.Tensor] = None, position_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[List[torch.FloatTensor]] = None, inputs_embeds: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_router_logits: Optional[bool] = None, cache_position: Optional[torch.LongTensor] = None, **flash_attn_kwargs: Unpack[FlashAttentionKwargs], ) -> MoeModelOutputWithPast: output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions output_router_logits = ( output_router_logits if output_router_logits is not None else self.config.output_router_logits ) output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) use_cache = use_cache if use_cache is not None else self.config.use_cache if (input_ids is None) ^ (inputs_embeds is not None): raise ValueError("You must specify exactly one of input_ids or inputs_embeds") if self.gradient_checkpointing and self.training: if use_cache: logger.warning_once( "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..." ) use_cache = False if use_cache and past_key_values is None: past_key_values = DynamicCache() if inputs_embeds is None: inputs_embeds = self.embed_tokens(input_ids) if cache_position is None: past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0 cache_position = torch.arange( past_seen_tokens, past_seen_tokens + inputs_embeds.shape[1], device=inputs_embeds.device ) if position_ids is None: position_ids = cache_position.unsqueeze(0) # print("atten mask:", attention_mask) # debug print causal_mask = self._update_causal_mask( attention_mask, inputs_embeds, cache_position, past_key_values, output_attentions ) # print("causal mask:", causal_mask) # debug print hidden_states = inputs_embeds # create position embeddings to be shared across the decoder layers position_embeddings = self.rotary_emb(hidden_states, position_ids) # decoder layers all_hidden_states = () if output_hidden_states else None all_self_attns = () if output_attentions else None all_router_logits = () if output_router_logits else None for layer_idx, decoder_layer in enumerate(self.layers): if output_hidden_states: all_hidden_states += (hidden_states,) if self.gradient_checkpointing and self.training: layer_outputs = self._gradient_checkpointing_func( partial(decoder_layer.__call__, **flash_attn_kwargs), hidden_states, causal_mask, position_ids, past_key_values, output_attentions, output_router_logits, use_cache, cache_position, position_embeddings if self.rope_layout[layer_idx] else None, ) else: layer_outputs = decoder_layer( hidden_states, attention_mask=causal_mask, position_ids=position_ids, past_key_value=past_key_values, output_attentions=output_attentions, output_router_logits=output_router_logits, use_cache=use_cache, cache_position=cache_position, position_embeddings=position_embeddings if self.rope_layout[layer_idx] else None, **flash_attn_kwargs, ) hidden_states = layer_outputs[0] if output_attentions: all_self_attns += (layer_outputs[1],) if output_router_logits: all_router_logits += (layer_outputs[-1],) hidden_states = self.norm(hidden_states) # add hidden states from the last decoder layer if output_hidden_states: all_hidden_states += (hidden_states,) return MoeModelOutputWithPast( last_hidden_state=hidden_states, past_key_values=past_key_values, hidden_states=all_hidden_states, attentions=all_self_attns, router_logits=all_router_logits, ) def _update_causal_mask( self, attention_mask: Union[torch.Tensor, "BlockMask"], input_tensor: torch.Tensor, cache_position: torch.Tensor, past_key_values: Cache, output_attentions: bool = False, ): if self.config._attn_implementation == "flash_attention_2": if attention_mask is not None and past_key_values is not None: is_padding_right = attention_mask[:, -1].sum().item() != input_tensor.size()[0] if is_padding_right: raise ValueError( "You are attempting to perform batched generation with padding_side='right'" " this may lead to unexpected behaviour for Flash Attention version of Smallthinker. Make sure to " " call `tokenizer.padding_side = 'left'` before tokenizing the input. " ) if attention_mask is not None and 0.0 in attention_mask: return attention_mask return None if self.config._attn_implementation == "flex_attention": if isinstance(attention_mask, torch.Tensor): attention_mask = make_flex_block_causal_mask(attention_mask) return attention_mask # For SDPA, when possible, we will rely on its `is_causal` argument instead of its `attn_mask` argument, in # order to dispatch on Flash Attention 2. This feature is not compatible with static cache, as SDPA will fail # to infer the attention mask. past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0 using_static_cache = isinstance(past_key_values, StaticCache) using_sliding_window_cache = isinstance(past_key_values, SlidingWindowCache) # When output attentions is True, sdpa implementation's forward method calls the eager implementation's forward if ( self.config._attn_implementation == "sdpa" and not (using_static_cache or using_sliding_window_cache) and not output_attentions ): if AttentionMaskConverter._ignore_causal_mask_sdpa( attention_mask, inputs_embeds=input_tensor, past_key_values_length=past_seen_tokens, sliding_window=self.config.sliding_window, is_training=self.training, ): return None dtype = input_tensor.dtype min_dtype = torch.finfo(dtype).min sequence_length = input_tensor.shape[1] # SlidingWindowCache or StaticCache if using_sliding_window_cache or using_static_cache: target_length = past_key_values.get_max_cache_shape() # DynamicCache or no cache else: target_length = ( attention_mask.shape[-1] if isinstance(attention_mask, torch.Tensor) else past_seen_tokens + sequence_length + 1 ) # In case the provided `attention` mask is 2D, we generate a causal mask here (4D). causal_mask = self._prepare_4d_causal_attention_mask_with_cache_position( attention_mask, sequence_length=sequence_length, target_length=target_length, dtype=dtype, cache_position=cache_position, batch_size=input_tensor.shape[0], config=self.config, past_key_values=past_key_values, ) if ( self.config._attn_implementation == "sdpa" and attention_mask is not None and attention_mask.device.type in ["cuda", "xpu", "npu"] and not output_attentions ): # Attend to all tokens in fully masked rows in the causal_mask, for example the relevant first rows when # using left padding. This is required by F.scaled_dot_product_attention memory-efficient attention path. # Details: https://github.com/pytorch/pytorch/issues/110213 causal_mask = AttentionMaskConverter._unmask_unattended(causal_mask, min_dtype) return causal_mask @staticmethod def _prepare_4d_causal_attention_mask_with_cache_position( attention_mask: torch.Tensor, sequence_length: int, target_length: int, dtype: torch.dtype, cache_position: torch.Tensor, batch_size: int, config: SmallthinkerConfig, past_key_values: Cache, ): """ Creates a causal 4D mask of shape `(batch_size, 1, query_length, key_value_length)` from a 2D mask of shape `(batch_size, key_value_length)`, or if the input `attention_mask` is already 4D, do nothing. Args: attention_mask (`torch.Tensor`): A 2D attention mask of shape `(batch_size, key_value_length)` or a 4D attention mask of shape `(batch_size, 1, query_length, key_value_length)`. sequence_length (`int`): The sequence length being processed. target_length (`int`): The target length: when generating with static cache, the mask should be as long as the static cache, to account for the 0 padding, the part of the cache that is not filled yet. dtype (`torch.dtype`): The dtype to use for the 4D attention mask. cache_position (`torch.Tensor`): Indices depicting the position of the input sequence tokens in the sequence. batch_size (`torch.Tensor`): Batch size. config (`SmallthinkerConfig`): The model's configuration class past_key_values (`Cache`): The cache class that is being used currently to generate """ if attention_mask is not None and attention_mask.dim() == 4: # In this case we assume that the mask comes already in inverted form and requires no inversion or slicing. causal_mask = attention_mask else: min_dtype = torch.finfo(dtype).min causal_mask = torch.full( (sequence_length, target_length), fill_value=min_dtype, dtype=dtype, device=cache_position.device ) diagonal_attend_mask = torch.arange(target_length, device=cache_position.device) > cache_position.reshape( -1, 1 ) if config.get_text_config().sliding_window is not None: # if we have sliding window, we should not attend to tokens beyond sliding window length, so we mask them out also # the check is needed to verify is current checkpoint was trained with sliding window or not if not isinstance(past_key_values, SlidingWindowCache) or sequence_length > target_length: sliding_attend_mask = torch.arange(target_length, device=cache_position.device) <= ( cache_position.reshape(-1, 1) - config.get_text_config().sliding_window ) diagonal_attend_mask.bitwise_or_(sliding_attend_mask) causal_mask *= diagonal_attend_mask causal_mask = causal_mask[None, None, :, :].expand(batch_size, 1, -1, -1) if attention_mask is not None: causal_mask = causal_mask.clone() # copy to contiguous memory for in-place edit if attention_mask.shape[-1] > target_length: attention_mask = attention_mask[:, :target_length] mask_length = attention_mask.shape[-1] padding_mask = causal_mask[:, :, :, :mask_length] + attention_mask[:, None, None, :].to( causal_mask.device ) padding_mask = padding_mask == 0 causal_mask[:, :, :, :mask_length] = causal_mask[:, :, :, :mask_length].masked_fill( padding_mask, min_dtype ) return causal_mask class KwargsForCausalLM(FlashAttentionKwargs, LossKwargs): ... def load_balancing_loss_func( gate_logits: Union[torch.Tensor, Tuple[torch.Tensor], None], num_experts: Optional[int] = None, top_k=2, attention_mask: Optional[torch.Tensor] = None, ) -> Union[torch.Tensor, int]: r""" Computes auxiliary load balancing loss as in Switch Transformer - implemented in Pytorch. See Switch Transformer (https://arxiv.org/abs/2101.03961) for more details. This function implements the loss function presented in equations (4) - (6) of the paper. It aims at penalizing cases where the routing between experts is too unbalanced. Args: gate_logits: Logits from the `gate`, should be a tuple of model.config.num_hidden_layers tensors of shape [batch_size X sequence_length, num_experts]. num_experts: Number of experts top_k: The number of experts to route per-token, can be also interpreted as the `top-k` routing parameter. attention_mask (`torch.Tensor`, *optional*): The attention_mask used in forward function shape [batch_size X sequence_length] if not None. Returns: The auxiliary loss. """ if gate_logits is None or not isinstance(gate_logits, tuple): return 0 if isinstance(gate_logits, tuple): compute_device = gate_logits[0].device concatenated_gate_logits = torch.cat([layer_gate.to(compute_device) for layer_gate in gate_logits], dim=0) routing_weights = torch.nn.functional.softmax(concatenated_gate_logits, dim=-1) _, selected_experts = torch.topk(routing_weights, top_k, dim=-1) expert_mask = torch.nn.functional.one_hot(selected_experts, num_experts) if attention_mask is None: # Compute the percentage of tokens routed to each experts tokens_per_expert = torch.mean(expert_mask.float(), dim=0) # Compute the average probability of routing to these experts router_prob_per_expert = torch.mean(routing_weights, dim=0) else: batch_size, sequence_length = attention_mask.shape num_hidden_layers = concatenated_gate_logits.shape[0] // (batch_size * sequence_length) # Compute the mask that masks all padding tokens as 0 with the same shape of expert_mask expert_attention_mask = ( attention_mask[None, :, :, None, None] .expand((num_hidden_layers, batch_size, sequence_length, top_k, num_experts)) .reshape(-1, top_k, num_experts) .to(compute_device) ) # Compute the percentage of tokens routed to each experts tokens_per_expert = torch.sum(expert_mask.float() * expert_attention_mask, dim=0) / torch.sum( expert_attention_mask, dim=0 ) # Compute the mask that masks all padding tokens as 0 with the same shape of tokens_per_expert router_per_expert_attention_mask = ( attention_mask[None, :, :, None] .expand((num_hidden_layers, batch_size, sequence_length, num_experts)) .reshape(-1, num_experts) .to(compute_device) ) # Compute the average probability of routing to these experts router_prob_per_expert = torch.sum(routing_weights * router_per_expert_attention_mask, dim=0) / torch.sum( router_per_expert_attention_mask, dim=0 ) overall_loss = torch.sum(tokens_per_expert * router_prob_per_expert.unsqueeze(0)) return overall_loss * num_experts # @auto_docstring class SmallthinkerForCausalLM(SmallthinkerPreTrainedModel, GenerationMixin): _tied_weights_keys = ["lm_head.weight"] def __init__(self, config): super().__init__(config) self.model = SmallthinkerModel(config) self.vocab_size = config.vocab_size # Handle tie / untie word embeddings self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False) # self.num_experts = config.num_local_experts # self.num_experts_per_tok = config.num_experts_per_tok # Initialize weights and apply final processing self.post_init() def get_input_embeddings(self): return self.model.embed_tokens def set_input_embeddings(self, value): self.model.embed_tokens = value def get_output_embeddings(self): return self.lm_head def set_output_embeddings(self, new_embeddings): self.lm_head = new_embeddings def set_decoder(self, decoder): self.model = decoder def get_decoder(self): return self.model @can_return_tuple # @auto_docstring def forward( self, input_ids: Optional[torch.LongTensor] = None, attention_mask: Optional[torch.Tensor] = None, position_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[List[torch.FloatTensor]] = None, inputs_embeds: Optional[torch.FloatTensor] = None, labels: Optional[torch.LongTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_router_logits: Optional[bool] = None, cache_position: Optional[torch.LongTensor] = None, logits_to_keep: Union[int, torch.Tensor] = 0, **kwargs: Unpack[KwargsForCausalLM], ) -> MoeCausalLMOutputWithPast: r""" labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): Labels for computing the masked language modeling loss. Indices should either be in `[0, ..., config.vocab_size]` or -100 (see `input_ids` docstring). Tokens with indices set to `-100` are ignored (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`. Example: ```python >>> from transformers import AutoTokenizer, SmallthinkerForCausalLM >>> model = SmallthinkerForCausalLM.from_pretrained("mistralai/Smallthinker-8x7B-v0.1") >>> tokenizer = AutoTokenizer.from_pretrained("mistralai/Smallthinker-8x7B-v0.1") >>> prompt = "Hey, are you conscious? Can you talk to me?" >>> inputs = tokenizer(prompt, return_tensors="pt") >>> # Generate >>> generate_ids = model.generate(inputs.input_ids, max_length=30) >>> tokenizer.batch_decode(generate_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0] "Hey, are you conscious? Can you talk to me?\nI'm not conscious, but I can talk to you." ```""" output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions output_router_logits = ( output_router_logits if output_router_logits is not None else self.config.output_router_logits ) output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) # decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn) outputs: MoeModelOutputWithPast = self.model( input_ids=input_ids, attention_mask=attention_mask, position_ids=position_ids, past_key_values=past_key_values, inputs_embeds=inputs_embeds, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, output_router_logits=output_router_logits, cache_position=cache_position, **kwargs, ) hidden_states = outputs.last_hidden_state # Only compute necessary logits, and do not upcast them to float if we are not computing the loss slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) else logits_to_keep logits = self.lm_head(hidden_states[:, slice_indices, :]) loss = None if labels is not None: loss = self.loss_function(logits, labels, self.vocab_size, **kwargs) aux_loss = None if output_router_logits: aux_loss = load_balancing_loss_func( outputs.router_logits, self.num_experts, self.num_experts_per_tok, attention_mask, ) if labels is not None: loss += self.router_aux_loss_coef * aux_loss.to(loss.device) # make sure to reside in the same device return MoeCausalLMOutputWithPast( loss=loss, aux_loss=aux_loss, logits=logits, past_key_values=outputs.past_key_values, hidden_states=outputs.hidden_states, attentions=outputs.attentions, router_logits=outputs.router_logits, ) # No such functions for now # #@auto_docstring( # custom_intro=""" # The Smallthinker Model transformer with a sequence classification head on top (linear layer). # [`SmallthinkerForSequenceClassification`] uses the last token in order to do the classification, as other causal models # (e.g. GPT-2) do. # Since it does classification on the last token, it requires to know the position of the last token. If a # `pad_token_id` is defined in the configuration, it finds the last token that is not a padding token in each row. If # no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since it cannot guess the # padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take the last value in # each row of the batch). # """ # ) # class SmallthinkerForSequenceClassification(SmallthinkerPreTrainedModel): # def __init__(self, config): # super().__init__(config) # self.num_labels = config.num_labels # self.model = SmallthinkerModel(config) # self.score = nn.Linear(config.hidden_size, self.num_labels, bias=False) # # Initialize weights and apply final processing # self.post_init() # def get_input_embeddings(self): # return self.model.embed_tokens # def set_input_embeddings(self, value): # self.model.embed_tokens = value # @can_return_tuple # #@auto_docstring # def forward( # self, # input_ids: Optional[torch.LongTensor] = None, # attention_mask: Optional[torch.Tensor] = None, # position_ids: Optional[torch.LongTensor] = None, # past_key_values: Optional[Cache] = None, # inputs_embeds: Optional[torch.FloatTensor] = None, # labels: Optional[torch.LongTensor] = None, # use_cache: Optional[bool] = None, # output_attentions: Optional[bool] = None, # output_hidden_states: Optional[bool] = None, # ) -> SequenceClassifierOutputWithPast: # r""" # labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*): # Labels for computing the sequence classification/regression loss. Indices should be in `[0, ..., # config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If # `config.num_labels > 1` a classification loss is computed (Cross-Entropy). # """ # transformer_outputs: BaseModelOutputWithPast = self.model( # input_ids, # attention_mask=attention_mask, # position_ids=position_ids, # past_key_values=past_key_values, # inputs_embeds=inputs_embeds, # use_cache=use_cache, # output_attentions=output_attentions, # output_hidden_states=output_hidden_states, # ) # hidden_states = transformer_outputs.last_hidden_state # logits = self.score(hidden_states) # if input_ids is not None: # batch_size = input_ids.shape[0] # else: # batch_size = inputs_embeds.shape[0] # if self.config.pad_token_id is None and batch_size != 1: # raise ValueError("Cannot handle batch sizes > 1 if no padding token is defined.") # if self.config.pad_token_id is None: # last_non_pad_token = -1 # elif input_ids is not None: # # To handle both left- and right- padding, we take the rightmost token that is not equal to pad_token_id # non_pad_mask = (input_ids != self.config.pad_token_id).to(logits.device, torch.int32) # token_indices = torch.arange(input_ids.shape[-1], device=logits.device, dtype=torch.int32) # last_non_pad_token = (token_indices * non_pad_mask).argmax(-1) # else: # last_non_pad_token = -1 # logger.warning_once( # f"{self.__class__.__name__} will not detect padding tokens in `inputs_embeds`. Results may be " # "unexpected if using padding tokens in conjunction with `inputs_embeds.`" # ) # pooled_logits = logits[torch.arange(batch_size, device=logits.device), last_non_pad_token] # loss = None # if labels is not None: # loss = self.loss_function(logits=logits, labels=labels, pooled_logits=pooled_logits, config=self.config) # return SequenceClassifierOutputWithPast( # loss=loss, # logits=pooled_logits, # past_key_values=transformer_outputs.past_key_values, # hidden_states=transformer_outputs.hidden_states, # attentions=transformer_outputs.attentions, # ) # #@auto_docstring # class SmallthinkerForTokenClassification(SmallthinkerPreTrainedModel): # def __init__(self, config): # super().__init__(config) # self.num_labels = config.num_labels # self.model = SmallthinkerModel(config) # if getattr(config, "classifier_dropout", None) is not None: # classifier_dropout = config.classifier_dropout # elif getattr(config, "hidden_dropout", None) is not None: # classifier_dropout = config.hidden_dropout # else: # classifier_dropout = 0.1 # self.dropout = nn.Dropout(classifier_dropout) # self.score = nn.Linear(config.hidden_size, config.num_labels) # # Initialize weights and apply final processing # self.post_init() # def get_input_embeddings(self): # return self.model.embed_tokens # def set_input_embeddings(self, value): # self.model.embed_tokens = value # @can_return_tuple # #@auto_docstring # def forward( # self, # input_ids: Optional[torch.LongTensor] = None, # attention_mask: Optional[torch.Tensor] = None, # position_ids: Optional[torch.LongTensor] = None, # past_key_values: Optional[Cache] = None, # inputs_embeds: Optional[torch.FloatTensor] = None, # labels: Optional[torch.LongTensor] = None, # use_cache: Optional[bool] = None, # output_attentions: Optional[bool] = None, # output_hidden_states: Optional[bool] = None, # ) -> TokenClassifierOutput: # r""" # labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*): # Labels for computing the sequence classification/regression loss. Indices should be in `[0, ..., # config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If # `config.num_labels > 1` a classification loss is computed (Cross-Entropy). # """ # outputs: BaseModelOutputWithPast = self.model( # input_ids, # attention_mask=attention_mask, # position_ids=position_ids, # past_key_values=past_key_values, # inputs_embeds=inputs_embeds, # use_cache=use_cache, # output_attentions=output_attentions, # output_hidden_states=output_hidden_states, # ) # sequence_output = outputs.last_hidden_state # sequence_output = self.dropout(sequence_output) # logits = self.score(sequence_output) # loss = None # if labels is not None: # loss = self.loss_function(logits, labels, self.config) # return TokenClassifierOutput( # loss=loss, # logits=logits, # hidden_states=outputs.hidden_states, # attentions=outputs.attentions, # ) # #@auto_docstring # class SmallthinkerForQuestionAnswering(SmallthinkerPreTrainedModel): # base_model_prefix = "model" # def __init__(self, config): # super().__init__(config) # self.qa_outputs = nn.Linear(config.hidden_size, 2) # self.model = SmallthinkerModel(config) # diff with Llama: transformer->model # # Initialize weights and apply final processing # self.post_init() # def get_input_embeddings(self): # return self.model.embed_tokens # def set_input_embeddings(self, value): # self.model.embed_tokens = value # @can_return_tuple # #@auto_docstring # def forward( # self, # input_ids: Optional[torch.LongTensor] = None, # attention_mask: Optional[torch.Tensor] = None, # position_ids: Optional[torch.LongTensor] = None, # past_key_values: Optional[Union[Cache, List[torch.FloatTensor]]] = None, # inputs_embeds: Optional[torch.FloatTensor] = None, # start_positions: Optional[torch.LongTensor] = None, # end_positions: Optional[torch.LongTensor] = None, # output_attentions: Optional[bool] = None, # output_hidden_states: Optional[bool] = None, # **kwargs, # ) -> QuestionAnsweringModelOutput: # r""" # start_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*): # Labels for position (index) of the start of the labelled span for computing the token classification loss. # Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence # are not taken into account for computing the loss. # end_positions (`torch.LongTensor` of shape `(batch_size,)`, *optional*): # Labels for position (index) of the end of the labelled span for computing the token classification loss. # Positions are clamped to the length of the sequence (`sequence_length`). Position outside of the sequence # are not taken into account for computing the loss. # """ # outputs: BaseModelOutputWithPast = self.model( # input_ids, # attention_mask=attention_mask, # position_ids=position_ids, # past_key_values=past_key_values, # inputs_embeds=inputs_embeds, # output_attentions=output_attentions, # output_hidden_states=output_hidden_states, # ) # sequence_output = outputs.last_hidden_state # logits = self.qa_outputs(sequence_output) # start_logits, end_logits = logits.split(1, dim=-1) # start_logits = start_logits.squeeze(-1).contiguous() # end_logits = end_logits.squeeze(-1).contiguous() # loss = None # if start_positions is not None and end_positions is not None: # loss = self.loss_function(start_logits, end_logits, start_positions, end_positions, **kwargs) # return QuestionAnsweringModelOutput( # loss=loss, # start_logits=start_logits, # end_logits=end_logits, # hidden_states=outputs.hidden_states, # attentions=outputs.attentions, # ) __all__ = [ "SmallthinkerForCausalLM", "SmallthinkerForQuestionAnswering", "SmallthinkerModel", "SmallthinkerPreTrainedModel", "SmallthinkerForSequenceClassification", "SmallthinkerForTokenClassification", ] if __name__ == "__main__": from transformers import AutoTokenizer, AutoModelForCausalLM test_config = SmallthinkerConfig() tokenizer = AutoTokenizer.from_pretrained("./qwen-tokenizer") text = "Once upon a day" tokens = tokenizer.encode_plus( text,add_special_tokens=True,return_tensors='pt') # print(tokens) test_model = AutoModelForCausalLM.from_pretrained(".").cuda() output = test_model.generate(tokens) otokens = tokenizer.decode(output[0]) # print(otokens)