Merge pull request #294 from kvcache-ai/feat-fast-MLA

Feat fast mla
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Atream 2025-02-14 19:40:36 +08:00 committed by GitHub
commit 885a91e7db
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5 changed files with 656 additions and 230 deletions

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@ -51,13 +51,34 @@ class StaticCache(transformers.StaticCache):
cache_shape = (max_batch_size, self.num_key_value_heads, self.max_cache_len, self.head_dim)
if config.architectures[0] == "DeepseekV2ForCausalLM" or config.architectures[0] == "DeepseekV3ForCausalLM":
# TODO: for deepseek, cache_shape is different whether using Absorbed MLA, check it automatically
# key_shape = (max_batch_size, self.num_key_value_heads, self.max_cache_len, config.qk_rope_head_dim + config.qk_nope_head_dim)
# value_shape = (max_batch_size, self.num_key_value_heads, self.max_cache_len, config.v_head_dim)
key_shape = (max_batch_size, 1, self.max_cache_len, config.qk_rope_head_dim)
value_shape = (max_batch_size, 1, self.max_cache_len, config.kv_lora_rank)
self.page_size = 64
self.max_pages = (self.max_cache_len + self.page_size - 1) // self.page_size
latent_shape = (self.max_pages, self.page_size, 1, config.kv_lora_rank + config.qk_rope_head_dim)
self.kv_lora_rank = config.kv_lora_rank
self.qk_rope_head_dim = config.qk_rope_head_dim
# TODO: support real page table
self.page_table_map = dict()
self.page_table_list = []
for idx in range(config.num_hidden_layers):
if isinstance(device, dict):
target_device = device[f"blk.{idx}.self_attn"]["generate_device"]
else:
target_device = device
if target_device not in self.page_table_map:
page_table = torch.zeros((max_batch_size, self.max_pages), dtype=torch.int32, device=target_device)
for seq_id in range(max_batch_size):
page_table[seq_id, :] = torch.arange(seq_id * self.max_pages, seq_id * self.max_pages + self.max_pages, dtype=torch.int32, device=target_device)
self.page_table_map[target_device] = page_table
self.page_table_list.append(self.page_table_map[target_device])
self.is_MLA = True
self.is_page = True
else:
key_shape = cache_shape
value_shape = cache_shape
self.is_MLA = False
self.past_tokens = []
self.num_hidden_layers = config.num_hidden_layers
@ -68,10 +89,17 @@ class StaticCache(transformers.StaticCache):
target_device = device[f"blk.{idx}.self_attn"]["generate_device"]
else:
target_device = device
new_layer_key_cache = torch.zeros(key_shape, dtype=self.dtype, device=target_device)
new_layer_value_cache = torch.zeros(value_shape, dtype=self.dtype, device=target_device)
torch._dynamo.mark_static_address(new_layer_key_cache)
torch._dynamo.mark_static_address(new_layer_value_cache)
if self.is_MLA:
new_layer_key_cache = torch.zeros(latent_shape, dtype=self.dtype, device=target_device)
new_layer_value_cache = None
torch._dynamo.mark_static_address(new_layer_key_cache)
else:
new_layer_key_cache = torch.zeros(key_shape, dtype=self.dtype, device=target_device)
new_layer_value_cache = torch.zeros(value_shape, dtype=self.dtype, device=target_device)
torch._dynamo.mark_static_address(new_layer_key_cache)
torch._dynamo.mark_static_address(new_layer_value_cache)
self.key_cache.append(new_layer_key_cache)
self.value_cache.append(new_layer_value_cache)
self.past_tokens.append(0)
@ -104,11 +132,21 @@ class StaticCache(transformers.StaticCache):
cache_position = cache_kwargs.get("cache_position")
k_out = self.key_cache[layer_idx]
v_out = self.value_cache[layer_idx]
#print(cache_position)
k_out[:, :, cache_position] = key_states
v_out[:, :, cache_position] = value_states
self.past_tokens[layer_idx] += cache_position.size(0)
return k_out, v_out
#print(cache_position)
if self.is_MLA:
page_idx = cache_position // self.page_size
page_offset = cache_position % self.page_size
# key shape (self.max_pages, self.page_size, 1, config.kv_lora_rank + config.qk_rope_head_dim)
#print("page_idx", page_idx)
#print("page_offset", page_offset)
k_out[page_idx, page_offset, :, :self.kv_lora_rank] = key_states
k_out[page_idx, page_offset, :, self.kv_lora_rank:] = value_states
return k_out, self.page_table_list[layer_idx]
else:
k_out[:, :, cache_position] = key_states
v_out[:, :, cache_position] = value_states
return k_out, v_out
def get_seq_length(self, layer_idx: Optional[int] = 0) -> int:
"""Returns the sequence length of the cached states that were seen by the model."""