KV 融合实现完成。改动总结: 速度微弱提升psnr略微上升

attention.py — 3处改动:
  1. __init__ 添加 _kv_fused = False 标志
  2.新增 fuse_kv() 方法:将 to_k + to_v → to_kv,同时处理 _ip/_as/_aa 辅助 KV 对
  2. bmm_forward 两个分支加_kv_fused 判断,用to_kv().chunk(2, dim=-1) 替代分别调用
This commit is contained in:
qhy
2026-02-11 12:36:38 +08:00
parent b558856e1e
commit 9a08e27a19
4 changed files with 180 additions and 38 deletions

View File

@@ -100,6 +100,7 @@ class CrossAttention(nn.Module):
self.agent_action_context_len = agent_action_context_len
self._kv_cache = {}
self._kv_cache_enabled = False
self._kv_fused = False
self.cross_attention_scale_learnable = cross_attention_scale_learnable
if self.image_cross_attention:
@@ -117,6 +118,27 @@ class CrossAttention(nn.Module):
self.register_parameter('alpha_caa',
nn.Parameter(torch.tensor(0.)))
def fuse_kv(self):
"""Fuse to_k/to_v into to_kv (2 Linear → 1). Works for all layers."""
k_w = self.to_k.weight # (inner_dim, context_dim)
v_w = self.to_v.weight
self.to_kv = nn.Linear(k_w.shape[1], k_w.shape[0] * 2, bias=False)
self.to_kv.weight = nn.Parameter(torch.cat([k_w, v_w], dim=0))
del self.to_k, self.to_v
if self.image_cross_attention:
for suffix in ('_ip', '_as', '_aa'):
k_attr = f'to_k{suffix}'
v_attr = f'to_v{suffix}'
kw = getattr(self, k_attr).weight
vw = getattr(self, v_attr).weight
fused = nn.Linear(kw.shape[1], kw.shape[0] * 2, bias=False)
fused.weight = nn.Parameter(torch.cat([kw, vw], dim=0))
setattr(self, f'to_kv{suffix}', fused)
delattr(self, k_attr)
delattr(self, v_attr)
self._kv_fused = True
return True
def forward(self, x, context=None, mask=None):
spatial_self_attn = (context is None)
k_ip, v_ip, out_ip = None, None, None
@@ -143,19 +165,28 @@ class CrossAttention(nn.Module):
self.agent_action_context_len +
self.text_context_len:, :]
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
k_aa = self.to_k_aa(context_agent_action)
v_aa = self.to_v_aa(context_agent_action)
if self._kv_fused:
k, v = self.to_kv(context_ins).chunk(2, dim=-1)
k_ip, v_ip = self.to_kv_ip(context_image).chunk(2, dim=-1)
k_as, v_as = self.to_kv_as(context_agent_state).chunk(2, dim=-1)
k_aa, v_aa = self.to_kv_aa(context_agent_action).chunk(2, dim=-1)
else:
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
k_aa = self.to_k_aa(context_agent_action)
v_aa = self.to_v_aa(context_agent_action)
else:
if not spatial_self_attn:
context = context[:, :self.text_context_len, :]
k = self.to_k(context)
v = self.to_v(context)
if self._kv_fused:
k, v = self.to_kv(context).chunk(2, dim=-1)
else:
k = self.to_k(context)
v = self.to_v(context)
q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> (b h) n d', h=h),
(q, k, v))
@@ -267,10 +298,14 @@ class CrossAttention(nn.Module):
elif self.image_cross_attention and not spatial_self_attn:
if context.shape[1] == self.text_context_len + self.video_length:
context_ins, context_image = context[:, :self.text_context_len, :], context[:,self.text_context_len:, :]
k = self.to_k(context)
v = self.to_v(context)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
if self._kv_fused:
k, v = self.to_kv(context).chunk(2, dim=-1)
k_ip, v_ip = self.to_kv_ip(context_image).chunk(2, dim=-1)
else:
k = self.to_k(context)
v = self.to_v(context)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k, v = map(_reshape_kv, (k, v))
k_ip, v_ip = map(_reshape_kv, (k_ip, v_ip))
if use_cache:
@@ -279,12 +314,17 @@ class CrossAttention(nn.Module):
context_agent_state = context[:, :self.agent_state_context_len, :]
context_ins = context[:, self.agent_state_context_len:self.agent_state_context_len+self.text_context_len, :]
context_image = context[:, self.agent_state_context_len+self.text_context_len:, :]
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
if self._kv_fused:
k, v = self.to_kv(context_ins).chunk(2, dim=-1)
k_ip, v_ip = self.to_kv_ip(context_image).chunk(2, dim=-1)
k_as, v_as = self.to_kv_as(context_agent_state).chunk(2, dim=-1)
else:
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
k, v = map(_reshape_kv, (k, v))
k_ip, v_ip = map(_reshape_kv, (k_ip, v_ip))
k_as, v_as = map(_reshape_kv, (k_as, v_as))
@@ -296,14 +336,20 @@ class CrossAttention(nn.Module):
context_ins = context[:, self.agent_state_context_len+self.agent_action_context_len:self.agent_state_context_len+self.agent_action_context_len+self.text_context_len, :]
context_image = context[:, self.agent_state_context_len+self.agent_action_context_len+self.text_context_len:, :]
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
k_aa = self.to_k_aa(context_agent_action)
v_aa = self.to_v_aa(context_agent_action)
if self._kv_fused:
k, v = self.to_kv(context_ins).chunk(2, dim=-1)
k_ip, v_ip = self.to_kv_ip(context_image).chunk(2, dim=-1)
k_as, v_as = self.to_kv_as(context_agent_state).chunk(2, dim=-1)
k_aa, v_aa = self.to_kv_aa(context_agent_action).chunk(2, dim=-1)
else:
k = self.to_k(context_ins)
v = self.to_v(context_ins)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
k_as = self.to_k_as(context_agent_state)
v_as = self.to_v_as(context_agent_state)
k_aa = self.to_k_aa(context_agent_action)
v_aa = self.to_v_aa(context_agent_action)
k, v = map(_reshape_kv, (k, v))
k_ip, v_ip = map(_reshape_kv, (k_ip, v_ip))
@@ -328,8 +374,11 @@ class CrossAttention(nn.Module):
if not spatial_self_attn:
assert 1 > 2, ">>> ERROR: you should never go into here ..."
context = context[:, :self.text_context_len, :]
k = self.to_k(context)
v = self.to_v(context)
if self._kv_fused:
k, v = self.to_kv(context).chunk(2, dim=-1)
else:
k = self.to_k(context)
v = self.to_v(context)
k, v = map(_reshape_kv, (k, v))
if use_cache:
self._kv_cache = {'k': k, 'v': v}