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sglang/python/sglang/multimodal_gen/runtime/models/dits/zimage.py
2026-01-21 23:02:24 +08:00

660 lines
21 KiB
Python

import math
from typing import Any, List, Optional, Tuple
import torch
import torch.nn as nn
from sglang.jit_kernel.norm import can_use_fused_inplace_qknorm
from sglang.multimodal_gen.configs.models.dits.zimage import ZImageDitConfig
from sglang.multimodal_gen.runtime.distributed import get_tp_world_size
from sglang.multimodal_gen.runtime.layers.activation import SiluAndMul
from sglang.multimodal_gen.runtime.layers.attention import USPAttention
from sglang.multimodal_gen.runtime.layers.layernorm import RMSNorm, apply_qk_norm
from sglang.multimodal_gen.runtime.layers.linear import (
ColumnParallelLinear,
MergedColumnParallelLinear,
ReplicatedLinear,
RowParallelLinear,
)
from sglang.multimodal_gen.runtime.layers.rotary_embedding import (
_apply_rotary_emb,
apply_flashinfer_rope_qk_inplace,
)
from sglang.multimodal_gen.runtime.models.dits.base import CachableDiT
from sglang.multimodal_gen.runtime.platforms import current_platform
from sglang.multimodal_gen.runtime.utils.layerwise_offload import OffloadableDiTMixin
from sglang.multimodal_gen.runtime.utils.logging_utils import init_logger
logger = init_logger(__name__)
_is_cuda = current_platform.is_cuda()
ADALN_EMBED_DIM = 256
SEQ_MULTI_OF = 32
class SelectFirstElement(nn.Module):
def __init__(self):
super().__init__()
def forward(self, x):
return x[0]
class TimestepEmbedder(nn.Module):
def __init__(self, out_size, mid_size=None, frequency_embedding_size=256):
super().__init__()
if mid_size is None:
mid_size = out_size
self.mlp = nn.ModuleList(
[
ColumnParallelLinear(
frequency_embedding_size, mid_size, bias=True, gather_output=False
),
nn.SiLU(),
RowParallelLinear(
mid_size, out_size, bias=True, input_is_parallel=True
),
]
)
self.frequency_embedding_size = frequency_embedding_size
@staticmethod
def timestep_embedding(t, dim, max_period=10000):
with torch.amp.autocast(current_platform.device_type, enabled=False):
half = dim // 2
freqs = torch.exp(
-math.log(max_period)
* torch.arange(start=0, end=half, dtype=torch.float32, device=t.device)
/ half
)
args = t[:, None].float() * freqs[None]
embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
if dim % 2:
embedding = torch.cat(
[embedding, torch.zeros_like(embedding[:, :1])], dim=-1
)
return embedding
def forward(self, t):
t_freq = self.timestep_embedding(t, self.frequency_embedding_size).to(
self.mlp[0].weight.dtype
)
t_emb, _ = self.mlp[0](t_freq)
t_emb = self.mlp[1](t_emb)
t_emb, _ = self.mlp[2](t_emb)
return t_emb
class FeedForward(nn.Module):
def __init__(self, dim: int, hidden_dim: int):
super().__init__()
# Use MergedColumnParallelLinear for gate and up projection (fused)
self.w13 = MergedColumnParallelLinear(
dim, [hidden_dim, hidden_dim], bias=False, gather_output=False
)
self.w2 = RowParallelLinear(hidden_dim, dim, bias=False, input_is_parallel=True)
self.act = SiluAndMul()
def forward(self, x):
x13, _ = self.w13(x)
x = self.act(x13)
out, _ = self.w2(x)
return out
class ZImageAttention(nn.Module):
def __init__(
self,
dim: int,
num_heads: int,
num_kv_heads: int,
qk_norm: bool = True,
eps: float = 1e-6,
) -> None:
super().__init__()
self.dim = dim
self.head_dim = dim // num_heads
self.num_heads = num_heads
self.num_kv_heads = num_kv_heads
self.qk_norm = qk_norm
tp_size = get_tp_world_size()
assert (
num_heads % tp_size == 0
), f"num_heads {num_heads} must be divisible by tp world size {tp_size}"
assert (
num_kv_heads % tp_size == 0
), f"num_kv_heads {num_kv_heads} must be divisible by tp world size {tp_size}"
self.local_num_heads = num_heads // tp_size
self.local_num_kv_heads = num_kv_heads // tp_size
self.to_q = ColumnParallelLinear(dim, dim, bias=False, gather_output=False)
self.to_k = ColumnParallelLinear(
dim, self.head_dim * num_kv_heads, bias=False, gather_output=False
)
self.to_v = ColumnParallelLinear(
dim, self.head_dim * num_kv_heads, bias=False, gather_output=False
)
if self.qk_norm:
self.norm_q = RMSNorm(self.head_dim, eps=eps)
self.norm_k = RMSNorm(self.head_dim, eps=eps)
else:
self.norm_q = None
self.norm_k = None
self.to_out = nn.ModuleList(
[RowParallelLinear(dim, dim, bias=False, input_is_parallel=True)]
)
self.attn = USPAttention(
num_heads=self.local_num_heads,
head_size=self.head_dim,
num_kv_heads=self.local_num_kv_heads,
dropout_rate=0,
softmax_scale=None,
causal=False,
)
def forward(
self,
hidden_states: torch.Tensor,
freqs_cis: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
):
q, _ = self.to_q(hidden_states)
k, _ = self.to_k(hidden_states)
v, _ = self.to_v(hidden_states)
q = q.view(*q.shape[:-1], self.local_num_heads, self.head_dim)
k = k.view(*k.shape[:-1], self.local_num_kv_heads, self.head_dim)
v = v.view(*v.shape[:-1], self.local_num_kv_heads, self.head_dim)
if self.qk_norm:
if (
_is_cuda
and (self.norm_q.variance_epsilon == self.norm_k.variance_epsilon)
and can_use_fused_inplace_qknorm(self.head_dim, q.dtype)
):
q, k = apply_qk_norm(
q=q,
k=k,
q_norm=self.norm_q,
k_norm=self.norm_k,
head_dim=self.head_dim,
allow_inplace=True,
)
else:
q = self.norm_q(q)
k = self.norm_k(k)
if freqs_cis is not None:
cos, sin = freqs_cis
if _is_cuda and q.shape == k.shape:
cos_sin_cache = torch.cat(
[
cos.to(dtype=torch.float32).contiguous(),
sin.to(dtype=torch.float32).contiguous(),
],
dim=-1,
)
q, k = apply_flashinfer_rope_qk_inplace(
q, k, cos_sin_cache, is_neox=False
)
else:
q = _apply_rotary_emb(q, cos, sin, is_neox_style=False)
k = _apply_rotary_emb(k, cos, sin, is_neox_style=False)
hidden_states = self.attn(q, k, v)
hidden_states = hidden_states.flatten(2)
hidden_states, _ = self.to_out[0](hidden_states)
return hidden_states
class ZImageTransformerBlock(nn.Module):
def __init__(
self,
layer_id: int,
dim: int,
n_heads: int,
n_kv_heads: int,
norm_eps: float,
qk_norm: bool,
modulation=True,
):
super().__init__()
self.dim = dim
self.head_dim = dim // n_heads
self.layer_id = layer_id
self.modulation = modulation
self.attention = ZImageAttention(
dim=dim,
num_heads=n_heads,
num_kv_heads=n_kv_heads,
qk_norm=qk_norm,
eps=1e-5,
)
self.feed_forward = FeedForward(dim=dim, hidden_dim=int(dim / 3 * 8))
self.attention_norm1 = RMSNorm(dim, eps=norm_eps)
self.ffn_norm1 = RMSNorm(dim, eps=norm_eps)
self.attention_norm2 = RMSNorm(dim, eps=norm_eps)
self.ffn_norm2 = RMSNorm(dim, eps=norm_eps)
if modulation:
self.adaLN_modulation = nn.Sequential(
ReplicatedLinear(min(dim, ADALN_EMBED_DIM), 4 * dim, bias=True)
)
def forward(
self,
x: torch.Tensor,
freqs_cis: Tuple[torch.Tensor, torch.Tensor],
adaln_input: Optional[torch.Tensor] = None,
):
if self.modulation:
assert adaln_input is not None
scale_msa_gate, _ = self.adaLN_modulation(adaln_input)
scale_msa, gate_msa, scale_mlp, gate_mlp = scale_msa_gate.unsqueeze(
1
).chunk(4, dim=2)
gate_msa, gate_mlp = gate_msa.tanh(), gate_mlp.tanh()
scale_msa, scale_mlp = 1.0 + scale_msa, 1.0 + scale_mlp
# Attention block
attn_out = self.attention(
self.attention_norm1(x) * scale_msa,
freqs_cis=freqs_cis,
)
x = x + gate_msa * self.attention_norm2(attn_out)
# FFN block
x = x + gate_mlp * self.ffn_norm2(
self.feed_forward(
self.ffn_norm1(x) * scale_mlp,
)
)
else:
# Attention block
attn_out = self.attention(
self.attention_norm1(x),
freqs_cis=freqs_cis,
)
x = x + self.attention_norm2(attn_out)
# FFN block
x = x + self.ffn_norm2(
self.feed_forward(
self.ffn_norm1(x),
)
)
return x
class FinalLayer(nn.Module):
def __init__(self, hidden_size, out_channels):
super().__init__()
self.norm_final = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.linear = ColumnParallelLinear(
hidden_size, out_channels, bias=True, gather_output=True
)
self.act = nn.SiLU()
self.adaLN_modulation = nn.Sequential(
nn.SiLU(),
ReplicatedLinear(min(hidden_size, ADALN_EMBED_DIM), hidden_size, bias=True),
)
def forward(self, x, c):
scale, _ = self.adaLN_modulation(c)
scale = 1.0 + scale
x = self.norm_final(x) * scale.unsqueeze(1)
x, _ = self.linear(x)
return x
class RopeEmbedder:
def __init__(
self,
theta: float = 256.0,
axes_dims: List[int] = (16, 56, 56),
axes_lens: List[int] = (64, 128, 128),
):
self.theta = theta
self.axes_dims = axes_dims
self.axes_lens = axes_lens
assert len(axes_dims) == len(
axes_lens
), "axes_dims and axes_lens must have the same length"
self.cos_cached = None
self.sin_cached = None
@staticmethod
def precompute_freqs(dim: List[int], end: List[int], theta: float = 256.0):
with torch.device("cpu"):
cos_list = []
sin_list = []
for i, (d, e) in enumerate(zip(dim, end)):
freqs = 1.0 / (
theta
** (torch.arange(0, d, 2, dtype=torch.float64, device="cpu") / d)
)
timestep = torch.arange(e, device=freqs.device, dtype=torch.float64)
freqs = torch.outer(timestep, freqs).float()
cos_list.append(torch.cos(freqs))
sin_list.append(torch.sin(freqs))
return cos_list, sin_list
def __call__(self, ids: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
"""
Args:
ids: [batch, len(axes_dims)] or [seq_len, len(axes_dims)]
Returns:
cos: [batch/seq, head_dim // 2]
sin: [batch/seq, head_dim // 2]
"""
assert ids.ndim == 2
assert ids.shape[-1] == len(self.axes_dims)
device = ids.device
if self.cos_cached is None:
self.cos_cached, self.sin_cached = self.precompute_freqs(
self.axes_dims, self.axes_lens, theta=self.theta
)
self.cos_cached = [c.to(device) for c in self.cos_cached]
self.sin_cached = [s.to(device) for s in self.sin_cached]
else:
if self.cos_cached[0].device != device:
self.cos_cached = [c.to(device) for c in self.cos_cached]
self.sin_cached = [s.to(device) for s in self.sin_cached]
cos_out = []
sin_out = []
for i in range(len(self.axes_dims)):
index = ids[:, i]
cos_out.append(self.cos_cached[i][index])
sin_out.append(self.sin_cached[i][index])
return torch.cat(cos_out, dim=-1), torch.cat(sin_out, dim=-1)
class ZImageTransformer2DModel(CachableDiT, OffloadableDiTMixin):
_supports_gradient_checkpointing = True
_no_split_modules = ["ZImageTransformerBlock"]
param_names_mapping = ZImageDitConfig().arch_config.param_names_mapping
param_names_mapping = ZImageDitConfig().arch_config.param_names_mapping
reverse_param_names_mapping = (
ZImageDitConfig().arch_config.reverse_param_names_mapping
)
def __init__(
self,
config: ZImageDitConfig,
hf_config: dict[str, Any],
) -> None:
super().__init__(config=config, hf_config=hf_config)
self.config_data = config # Store config
arch_config = config.arch_config
self.in_channels = arch_config.in_channels
self.out_channels = arch_config.out_channels
self.all_patch_size = arch_config.all_patch_size
self.all_f_patch_size = arch_config.all_f_patch_size
self.dim = arch_config.dim
self.n_heads = arch_config.num_attention_heads
self.rope_theta = arch_config.rope_theta
self.t_scale = arch_config.t_scale
self.gradient_checkpointing = False
assert len(self.all_patch_size) == len(self.all_f_patch_size)
all_x_embedder = {}
all_final_layer = {}
for patch_idx, (patch_size, f_patch_size) in enumerate(
zip(self.all_patch_size, self.all_f_patch_size)
):
x_embedder = ColumnParallelLinear(
f_patch_size * patch_size * patch_size * self.in_channels,
self.dim,
bias=True,
gather_output=True,
)
all_x_embedder[f"{patch_size}-{f_patch_size}"] = x_embedder
final_layer = FinalLayer(
self.dim, patch_size * patch_size * f_patch_size * self.out_channels
)
all_final_layer[f"{patch_size}-{f_patch_size}"] = final_layer
self.all_x_embedder = nn.ModuleDict(all_x_embedder)
self.all_final_layer = nn.ModuleDict(all_final_layer)
self.noise_refiner = nn.ModuleList(
[
ZImageTransformerBlock(
1000 + layer_id,
self.dim,
self.n_heads,
arch_config.n_kv_heads,
arch_config.norm_eps,
arch_config.qk_norm,
modulation=True,
)
for layer_id in range(arch_config.n_refiner_layers)
]
)
self.context_refiner = nn.ModuleList(
[
ZImageTransformerBlock(
layer_id,
self.dim,
self.n_heads,
arch_config.n_kv_heads,
arch_config.norm_eps,
arch_config.qk_norm,
modulation=False,
)
for layer_id in range(arch_config.n_refiner_layers)
]
)
self.t_embedder = TimestepEmbedder(
min(self.dim, ADALN_EMBED_DIM), mid_size=1024
)
self.cap_embedder = nn.Sequential(
RMSNorm(arch_config.cap_feat_dim, eps=arch_config.norm_eps),
ReplicatedLinear(arch_config.cap_feat_dim, self.dim, bias=True),
)
self.x_pad_token = nn.Parameter(torch.empty((1, self.dim)))
self.cap_pad_token = nn.Parameter(torch.empty((1, self.dim)))
self.layers = nn.ModuleList(
[
ZImageTransformerBlock(
layer_id,
self.dim,
self.n_heads,
arch_config.n_kv_heads,
arch_config.norm_eps,
arch_config.qk_norm,
)
for layer_id in range(arch_config.num_layers)
]
)
head_dim = self.dim // self.n_heads
assert head_dim == sum(arch_config.axes_dims)
self.axes_dims = arch_config.axes_dims
self.axes_lens = arch_config.axes_lens
self.rotary_emb = RopeEmbedder(
theta=self.rope_theta, axes_dims=self.axes_dims, axes_lens=self.axes_lens
)
self.layer_names = ["layers"]
def unpatchify(
self, x: List[torch.Tensor], size: List[Tuple], patch_size, f_patch_size
) -> List[torch.Tensor]:
pH = pW = patch_size
pF = f_patch_size
bsz = len(x)
assert len(size) == bsz
for i in range(bsz):
F, H, W = size[i]
ori_len = (F // pF) * (H // pH) * (W // pW)
# "f h w pf ph pw c -> c (f pf) (h ph) (w pw)"
x[i] = (
x[i][:ori_len]
.view(F // pF, H // pH, W // pW, pF, pH, pW, self.out_channels)
.permute(6, 0, 3, 1, 4, 2, 5)
.reshape(self.out_channels, F, H, W)
)
return x
@staticmethod
def create_coordinate_grid(size, start=None, device=None):
if start is None:
start = (0 for _ in size)
axes = [
torch.arange(x0, x0 + span, dtype=torch.int32, device=device)
for x0, span in zip(start, size)
]
grids = torch.meshgrid(axes, indexing="ij")
return torch.stack(grids, dim=-1)
def patchify_and_embed(
self,
all_image: List[torch.Tensor],
all_cap_feats: List[torch.Tensor],
patch_size: int,
f_patch_size: int,
):
assert len(all_image) == len(all_cap_feats) == 1
image = all_image[0] # C, F, H, W
cap_feat = all_cap_feats[0] # L, D
pH = pW = patch_size
pF = f_patch_size
device = image.device
all_image_out = []
all_image_size = []
all_cap_feats_out = []
# ------------ Process Caption ------------
cap_ori_len = cap_feat.size(0)
cap_padding_len = (-cap_ori_len) % SEQ_MULTI_OF
# padded feature
cap_padded_feat = torch.cat(
[cap_feat, cap_feat[-1:].repeat(cap_padding_len, 1)],
dim=0,
)
all_cap_feats_out.append(cap_padded_feat)
# ------------ Process Image ------------
C, F, H, W = image.size()
all_image_size.append((F, H, W))
F_tokens, H_tokens, W_tokens = F // pF, H // pH, W // pW
image = image.view(C, F_tokens, pF, H_tokens, pH, W_tokens, pW)
# "c f pf h ph w pw -> (f h w) (pf ph pw c)"
image = image.permute(1, 3, 5, 2, 4, 6, 0).reshape(
F_tokens * H_tokens * W_tokens, pF * pH * pW * C
)
image_ori_len = image.size(0)
image_padding_len = (-image_ori_len) % SEQ_MULTI_OF
# padded feature
image_padded_feat = torch.cat(
[image, image[-1:].repeat(image_padding_len, 1)],
dim=0,
)
all_image_out.append(image_padded_feat)
return (
all_image_out,
all_cap_feats_out,
all_image_size,
)
def forward(
self,
hidden_states: List[torch.Tensor],
encoder_hidden_states: List[torch.Tensor],
timestep,
guidance=0,
patch_size=2,
f_patch_size=1,
freqs_cis=None,
**kwargs,
):
assert patch_size in self.all_patch_size
assert f_patch_size in self.all_f_patch_size
x = hidden_states
cap_feats = encoder_hidden_states
timestep = 1000.0 - timestep
t = timestep
bsz = 1
device = x[0].device
t = self.t_embedder(t)
adaln_input = t.type_as(x)
(
x,
cap_feats,
x_size,
) = self.patchify_and_embed(x, cap_feats, patch_size, f_patch_size)
x = torch.cat(x, dim=0)
x, _ = self.all_x_embedder[f"{patch_size}-{f_patch_size}"](x)
x_freqs_cis = freqs_cis[1]
x = x.unsqueeze(0)
x_freqs_cis = x_freqs_cis
for layer in self.noise_refiner:
x = layer(x, x_freqs_cis, adaln_input)
cap_feats = torch.cat(cap_feats, dim=0)
cap_feats, _ = self.cap_embedder(cap_feats)
cap_freqs_cis = freqs_cis[0]
cap_feats = cap_feats.unsqueeze(0)
for layer in self.context_refiner:
cap_feats = layer(cap_feats, cap_freqs_cis)
unified = torch.cat([x, cap_feats], dim=1)
unified_freqs_cis = (
torch.cat([x_freqs_cis[0], cap_freqs_cis[0]], dim=0),
torch.cat([x_freqs_cis[1], cap_freqs_cis[1]], dim=0),
)
for layer in self.layers:
unified = layer(unified, unified_freqs_cis, adaln_input)
unified = self.all_final_layer[f"{patch_size}-{f_patch_size}"](
unified, adaln_input
)
unified = list(unified.unbind(dim=0))
x = self.unpatchify(unified, x_size, patch_size, f_patch_size)
return -x[0]
EntryClass = ZImageTransformer2DModel