61 transformer blocks › 60 MoE blocks › Latent attention › Query heads
Unrotated query part
×tensorq_pe · 772
Each head’s 64 rotary features before rotation.
- shape
- [B batch, 64 heads, 1 position, 64 rotary]
Sources
Contextual evidence from Split rotary heads
Queries are produced through a low-rank latent and split into a non-rotated and a rotated part.
mla-queries · moonshotai/Kimi-K2-Instruct / modeling_deepseek.py
Pinned revision fd1984e2b7a3 ↗ · lines 767–774
Read code excerpt
if self.q_lora_rank is None:
q = self.q_proj(hidden_states)
else:
q = self.q_b_proj(self.q_a_layernorm(self.q_a_proj(hidden_states)))
q = q.view(bsz, q_len, self.num_heads, self.q_head_dim).transpose(1, 2)
q_nope, q_pe = torch.split(
q, [self.qk_nope_head_dim, self.qk_rope_head_dim], dim=-1
)Contextual evidence from Rotate query part
Rotary embedding rotates consecutive feature pairs: the implementation regroups each pair before applying rotate_half, which multiplies pair (2j, 2j+1) by position’s angle for frequency j.
apply-rope · moonshotai/Kimi-K2-Instruct / modeling_deepseek.py
Pinned revision fd1984e2b7a3 ↗ · lines 339–371
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def apply_rotary_pos_emb(q, k, cos, sin, position_ids, 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`):
The position indices of the tokens corresponding to the query and key tensors. For example, this can be
used to pass offsetted position ids when working with a KV-cache.
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[position_ids].unsqueeze(unsqueeze_dim)
sin = sin[position_ids].unsqueeze(unsqueeze_dim)
b, h, s, d = q.shape
q = q.view(b, h, s, d // 2, 2).transpose(4, 3).reshape(b, h, s, d)
b, h, s, d = k.shape
k = k.view(b, h, s, d // 2, 2).transpose(4, 3).reshape(b, h, s, d)
q_embed = (q * cos) + (rotate_half(q) * sin)
k_embed = (k * cos) + (rotate_half(k) * sin)
return q_embed, k_embedContextual evidence from Rotate query part
Rotary coefficients: the YaRN correction range in rotary pairs, the linear ramp between base and interpolated frequencies, and cos/sin tables scaled by the ratio of the two YaRN corrections.
rope · moonshotai/Kimi-K2-Instruct / modeling_deepseek.py
Pinned revision fd1984e2b7a3 ↗ · lines 226–327
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def yarn_find_correction_dim(
num_rotations, dim, base=10000, max_position_embeddings=2048
):
return (dim * math.log(max_position_embeddings / (num_rotations * 2 * math.pi))) / (
2 * math.log(base)
)
# Find dim range bounds based on rotations
def yarn_find_correction_range(
low_rot, high_rot, dim, base=10000, max_position_embeddings=2048
):
low = math.floor(
yarn_find_correction_dim(low_rot, dim, base, max_position_embeddings)
)
high = math.ceil(
yarn_find_correction_dim(high_rot, dim, base, max_position_embeddings)
)
return max(low, 0), min(high, dim - 1) # Clamp values just in case
def yarn_get_mscale(scale=1, mscale=1):
if scale <= 1:
return 1.0
return 0.1 * mscale * math.log(scale) + 1.0
def yarn_linear_ramp_mask(min, max, dim):
if min == max:
max += 0.001 # Prevent singularity
linear_func = (torch.arange(dim, dtype=torch.float32) - min) / (max - min)
ramp_func = torch.clamp(linear_func, 0, 1)
return ramp_func… lines 260–284 omitted …
def _set_cos_sin_cache(self, seq_len, device, dtype):
self.max_seq_len_cached = seq_len
dim = self.dim
freq_extra = 1.0 / (
self.base
** (torch.arange(0, dim, 2, dtype=torch.float32, device=device) / dim)
)
freq_inter = 1.0 / (
self.scaling_factor
* self.base
** (torch.arange(0, dim, 2, dtype=torch.float32, device=device) / dim)
)
low, high = yarn_find_correction_range(
self.beta_fast,
self.beta_slow,
dim,
self.base,
self.original_max_position_embeddings,
)
inv_freq_mask = 1.0 - yarn_linear_ramp_mask(low, high, dim // 2).to(
device=device, dtype=torch.float32
)
inv_freq = freq_inter * (1 - inv_freq_mask) + freq_extra * inv_freq_mask
self.register_buffer("inv_freq", inv_freq, persistent=False)
t = torch.arange(seq_len, device=device, dtype=torch.float32)
freqs = torch.outer(t, inv_freq)
_mscale = float(
yarn_get_mscale(self.scaling_factor, self.mscale)
/ yarn_get_mscale(self.scaling_factor, self.mscale_all_dim)
)
emb = torch.cat((freqs, freqs), dim=-1)
self.register_buffer(
"cos_cached", (emb.cos() * _mscale).to(dtype), persistent=False
)
self.register_buffer(
"sin_cached", (emb.sin() * _mscale).to(dtype), persistent=False
)