Refactor MHA & MLA KV caches to support FP4 (#13547)

Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com>
This commit is contained in:
Ho-Ren (Jack) Chuang
2025-11-22 11:13:43 -08:00
committed by GitHub
parent 5a4394a342
commit 3990b84bd3
2 changed files with 395 additions and 256 deletions
@@ -111,7 +111,9 @@ from sglang.srt.mem_cache.memory_pool import (
HybridLinearKVPool,
HybridReqToTokenPool,
MHATokenToKVPool,
MHATokenToKVPoolFP4,
MLATokenToKVPool,
MLATokenToKVPoolFP4,
NSATokenToKVPool,
ReqToTokenPool,
SWAKVPool,
@@ -1802,18 +1804,32 @@ class ModelRunner:
)
elif self.use_mla_backend and not self.mambaish_config:
assert not is_nsa_model
self.token_to_kv_pool = MLATokenToKVPool(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
kv_lora_rank=self.model_config.kv_lora_rank,
qk_rope_head_dim=self.model_config.qk_rope_head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
)
if is_float4_e2m1fn_x2(self.kv_cache_dtype):
self.token_to_kv_pool = MLATokenToKVPoolFP4(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
kv_lora_rank=self.model_config.kv_lora_rank,
qk_rope_head_dim=self.model_config.qk_rope_head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
)
else:
self.token_to_kv_pool = MLATokenToKVPool(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
kv_lora_rank=self.model_config.kv_lora_rank,
qk_rope_head_dim=self.model_config.qk_rope_head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
)
elif self.server_args.enable_double_sparsity:
self.token_to_kv_pool = DoubleSparseTokenToKVPool(
self.max_total_num_tokens,
@@ -1870,24 +1886,44 @@ class ModelRunner:
**extra_args,
)
else:
self.token_to_kv_pool = MHATokenToKVPool(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
head_num=self.model_config.get_num_kv_heads(
get_attention_tp_size()
),
head_dim=self.model_config.head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
enable_alt_stream=not self.server_args.enable_pdmux,
enable_kv_cache_copy=(
self.server_args.speculative_algorithm is not None
),
)
if is_float4_e2m1fn_x2(self.kv_cache_dtype):
self.token_to_kv_pool = MHATokenToKVPoolFP4(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
head_num=self.model_config.get_num_kv_heads(
get_attention_tp_size()
),
head_dim=self.model_config.head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
enable_alt_stream=not self.server_args.enable_pdmux,
enable_kv_cache_copy=(
self.server_args.speculative_algorithm is not None
),
)
else:
self.token_to_kv_pool = MHATokenToKVPool(
self.max_total_num_tokens,
page_size=self.page_size,
dtype=self.kv_cache_dtype,
head_num=self.model_config.get_num_kv_heads(
get_attention_tp_size()
),
head_dim=self.model_config.head_dim,
layer_num=self.num_effective_layers,
device=self.device,
enable_memory_saver=self.server_args.enable_memory_saver,
start_layer=self.start_layer,
end_layer=self.end_layer,
enable_alt_stream=not self.server_args.enable_pdmux,
enable_kv_cache_copy=(
self.server_args.speculative_algorithm is not None
),
)
# Initialize token_to_kv_pool_allocator
need_sort = self.server_args.disaggregation_mode in ("decode", "prefill")