sd-webui-fabric/scripts/weighted_attention.py

342 lines
13 KiB
Python

import math
import psutil
import torch
import torch.nn.functional
from torch import einsum
from einops import rearrange
from ldm.util import default
from modules import shared, devices, sd_hijack
from modules.hypernetworks import hypernetwork
from modules.sd_hijack_optimizations import (
get_xformers_flash_attention_op,
get_available_vram,
)
try:
import xformers
import xformers.ops
except ImportError:
pass
def get_weighted_attn_fn():
method = sd_hijack.model_hijack.optimization_method
if method is None:
return weighted_split_cross_attention_forward
method = method.lower()
if method not in ['none', 'sdp-no-mem', 'sdp', 'xformers', 'sub-quadratic', 'v1', 'invokeai', 'doggettx']:
print(f"[FABRIC] Warning: Unknown attention optimization method {method}.")
return weighted_split_cross_attention_forward
if method == 'none':
return weighted_split_cross_attention_forward
elif method == 'xformers':
return weighted_xformers_attention_forward
elif method == 'sdp-no-mem':
return weighted_scaled_dot_product_no_mem_attention_forward
elif method == 'sdp':
return weighted_scaled_dot_product_attention_forward
elif method == 'doggettx':
return weighted_split_cross_attention_forward
elif method == 'invokeai':
return weighted_split_cross_attention_forward_invokeAI
elif method == 'sub-quadratic':
print(f"[FABRIC] Warning: Sub-quadratic attention is not supported yet. Please open an issue if you need this for your workflow. Falling back to split attention.")
return weighted_split_cross_attention_forward
elif method == 'v1':
print(f"[FABRIC] Warning: V1 attention is not supported yet. Please open an issue if you need this for your workflow. Falling back to split attention.")
return weighted_split_cross_attention_forward
else:
return weighted_split_cross_attention_forward
def weighted_attention(self, attn_fn, x, context=None, weights=None, **kwargs):
if weights is None:
return attn_fn(x, context=context, **kwargs)
weighted_attn_fn = get_weighted_attn_fn()
return weighted_attn_fn(self, x, context=context, weights=weights, **kwargs)
def _get_attn_bias(weights, shape=None, dtype=torch.float32):
# shape of weights needs to be divisible by 8 in order for xformers attn bias to work
last_dim = ((weights.shape[-1] - 1) // 8 + 1) * 8
w_bias = torch.zeros(weights.shape[:-1] + (last_dim,), device=weights.device, dtype=weights.dtype)
min_val = torch.finfo(dtype).min
w_bias[..., :weights.shape[-1]] = weights.log().clamp(min=min_val)
if shape is not None:
assert shape[-1] == weights.shape[-1], "Last dimension of shape must match last dimension of weights (number of keys)"
w_bias = w_bias.view([1] * (len(shape) - 1) + [-1]).expand(shape[:-1] + (last_dim,))
# cast first in order to preserve multiple-of-8 stride
w_bias = w_bias.to(dtype=dtype)
w_bias = w_bias[..., :weights.shape[-1]]
return w_bias
### The following attn functions are copied and adapted from modules.sd_hijack_optimizations
# --- InvokeAI ---
mem_total_gb = psutil.virtual_memory().total // (1 << 30)
def einsum_op_compvis(q, k, v, weights=None):
s = einsum('b i d, b j d -> b i j', q, k)
if weights is not None:
s += _get_attn_bias(weights, s.shape, s.dtype)
s = s.softmax(dim=-1, dtype=s.dtype)
return einsum('b i j, b j d -> b i d', s, v)
def einsum_op_slice_0(q, k, v, slice_size, weights=None):
r = torch.zeros(q.shape[0], q.shape[1], v.shape[2], device=q.device, dtype=q.dtype)
for i in range(0, q.shape[0], slice_size):
end = i + slice_size
r[i:end] = einsum_op_compvis(q[i:end], k[i:end], v[i:end], weights)
return r
def einsum_op_slice_1(q, k, v, slice_size, weights=None):
r = torch.zeros(q.shape[0], q.shape[1], v.shape[2], device=q.device, dtype=q.dtype)
for i in range(0, q.shape[1], slice_size):
end = i + slice_size
r[:, i:end] = einsum_op_compvis(q[:, i:end], k, v, weights)
return r
def einsum_op_mps_v1(q, k, v, weights=None):
if q.shape[0] * q.shape[1] <= 2**16: # (512x512) max q.shape[1]: 4096
return einsum_op_compvis(q, k, v, weights)
else:
slice_size = math.floor(2**30 / (q.shape[0] * q.shape[1]))
if slice_size % 4096 == 0:
slice_size -= 1
return einsum_op_slice_1(q, k, v, slice_size, weights)
def einsum_op_mps_v2(q, k, v, weights=None):
if mem_total_gb > 8 and q.shape[0] * q.shape[1] <= 2**16:
return einsum_op_compvis(q, k, v, weights)
else:
return einsum_op_slice_0(q, k, v, 1, weights)
def einsum_op_tensor_mem(q, k, v, max_tensor_mb, weights=None):
size_mb = q.shape[0] * q.shape[1] * k.shape[1] * q.element_size() // (1 << 20)
if size_mb <= max_tensor_mb:
return einsum_op_compvis(q, k, v, weights)
div = 1 << int((size_mb - 1) / max_tensor_mb).bit_length()
if div <= q.shape[0]:
return einsum_op_slice_0(q, k, v, q.shape[0] // div, weights)
return einsum_op_slice_1(q, k, v, max(q.shape[1] // div, 1), weights)
def einsum_op_cuda(q, k, v, weights=None):
stats = torch.cuda.memory_stats(q.device)
mem_active = stats['active_bytes.all.current']
mem_reserved = stats['reserved_bytes.all.current']
mem_free_cuda, _ = torch.cuda.mem_get_info(q.device)
mem_free_torch = mem_reserved - mem_active
mem_free_total = mem_free_cuda + mem_free_torch
# Divide factor of safety as there's copying and fragmentation
return einsum_op_tensor_mem(q, k, v, mem_free_total / 3.3 / (1 << 20), weights)
def einsum_op(q, k, v, weights=None):
if q.device.type == 'cuda':
return einsum_op_cuda(q, k, v, weights)
if q.device.type == 'mps':
if mem_total_gb >= 32 and q.shape[0] % 32 != 0 and q.shape[0] * q.shape[1] < 2**18:
return einsum_op_mps_v1(q, k, v, weights)
return einsum_op_mps_v2(q, k, v, weights)
# Smaller slices are faster due to L2/L3/SLC caches.
# Tested on i7 with 8MB L3 cache.
return einsum_op_tensor_mem(q, k, v, 32, weights)
def weighted_split_cross_attention_forward_invokeAI(self, x, context=None, mask=None, weights=None):
h = self.heads
q = self.to_q(x)
context = default(context, x)
context_k, context_v = hypernetwork.apply_hypernetworks(shared.loaded_hypernetworks, context)
k = self.to_k(context_k)
v = self.to_v(context_v)
del context, context_k, context_v, x
dtype = q.dtype
if shared.opts.upcast_attn:
q, k, v = q.float(), k.float(), v if v.device.type == 'mps' else v.float()
with devices.without_autocast(disable=not shared.opts.upcast_attn):
k = k * self.scale
q, k, v = (rearrange(t, 'b n (h d) -> (b h) n d', h=h) for t in (q, k, v))
r = einsum_op(q, k, v, weights)
r = r.to(dtype)
return self.to_out(rearrange(r, '(b h) n d -> b n (h d)', h=h))
# --- end InvokeAI ---
def weighted_xformers_attention_forward(self, x, context=None, mask=None, weights=None):
h = self.heads
q_in = self.to_q(x)
context = default(context, x)
context_k, context_v = hypernetwork.apply_hypernetworks(shared.loaded_hypernetworks, context)
k_in = self.to_k(context_k)
v_in = self.to_v(context_v)
q, k, v = (rearrange(t, 'b n (h d) -> b n h d', h=h) for t in (q_in, k_in, v_in))
del q_in, k_in, v_in
dtype = q.dtype
if shared.opts.upcast_attn:
q, k, v = q.float(), k.float(), v.float()
### FABRIC ###
bias_shape = (q.size(0), q.size(2), q.size(1), k.size(1)) # (bs, h, nq, nk)
if weights is not None:
attn_bias = _get_attn_bias(weights, bias_shape, dtype=q.dtype)
else:
attn_bias = None
### END FABRIC ###
out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=attn_bias, op=get_xformers_flash_attention_op(q, k, v))
out = out.to(dtype)
out = rearrange(out, 'b n h d -> b n (h d)', h=h)
return self.to_out(out)
def weighted_scaled_dot_product_attention_forward(self, x, context=None, mask=None, weights=None):
batch_size, sequence_length, inner_dim = x.shape
if mask is not None:
mask = self.prepare_attention_mask(mask, sequence_length, batch_size)
mask = mask.view(batch_size, self.heads, -1, mask.shape[-1])
h = self.heads
q_in = self.to_q(x)
context = default(context, x)
context_k, context_v = hypernetwork.apply_hypernetworks(shared.loaded_hypernetworks, context)
k_in = self.to_k(context_k)
v_in = self.to_v(context_v)
head_dim = inner_dim // h
q = q_in.view(batch_size, -1, h, head_dim).transpose(1, 2)
k = k_in.view(batch_size, -1, h, head_dim).transpose(1, 2)
v = v_in.view(batch_size, -1, h, head_dim).transpose(1, 2)
del q_in, k_in, v_in
dtype = q.dtype
if shared.opts.upcast_attn:
q, k, v = q.float(), k.float(), v.float()
### FABRIC ###
mask_shape = q.shape[:3] + (k.shape[2],) # (bs, h, nq, nk)
if mask is None:
mask = 0
else:
mask.masked_fill(not mask, -float('inf')) if mask.dtype==torch.bool else mask
mask = mask.to(dtype=q.dtype)
if weights is not None:
w_bias = _get_attn_bias(weights, mask_shape, dtype=q.dtype)
mask += w_bias
### END FABRIC ###
# the output of sdp = (batch, num_heads, seq_len, head_dim)
hidden_states = torch.nn.functional.scaled_dot_product_attention(
q, k, v, attn_mask=mask, dropout_p=0.0, is_causal=False
)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, h * head_dim)
hidden_states = hidden_states.to(dtype)
# linear proj
hidden_states = self.to_out[0](hidden_states)
# dropout
hidden_states = self.to_out[1](hidden_states)
return hidden_states
def weighted_scaled_dot_product_no_mem_attention_forward(self, x, context=None, mask=None, weights=None):
with torch.backends.cuda.sdp_kernel(enable_flash=True, enable_math=True, enable_mem_efficient=False):
return weighted_scaled_dot_product_attention_forward(self, x, context, mask, weights)
def weighted_split_cross_attention_forward(self, x, context=None, mask=None, weights=None):
h = self.heads
q_in = self.to_q(x)
context = default(context, x)
context_k, context_v = hypernetwork.apply_hypernetworks(shared.loaded_hypernetworks, context)
k_in = self.to_k(context_k)
v_in = self.to_v(context_v)
dtype = q_in.dtype
if shared.opts.upcast_attn:
q_in, k_in, v_in = q_in.float(), k_in.float(), v_in if v_in.device.type == 'mps' else v_in.float()
with devices.without_autocast(disable=not shared.opts.upcast_attn):
k_in = k_in * self.scale
del context, x
q, k, v = (rearrange(t, 'b n (h d) -> (b h) n d', h=h) for t in (q_in, k_in, v_in))
del q_in, k_in, v_in
r1 = torch.zeros(q.shape[0], q.shape[1], v.shape[2], device=q.device, dtype=q.dtype)
mem_free_total = get_available_vram()
gb = 1024 ** 3
tensor_size = q.shape[0] * q.shape[1] * k.shape[1] * q.element_size()
modifier = 3 if q.element_size() == 2 else 2.5
mem_required = tensor_size * modifier
# FABRIC incurs some batch-size-dependend overhead. Found empirically on RTX 3090.
bs = q.shape[0] / 8 # batch size
mem_required *= 1/(bs + 1) + 1.25
mem_required *= 1.05 # safety margin
steps = 1
if mem_required > mem_free_total:
steps = 2 ** (math.ceil(math.log(mem_required / mem_free_total, 2)))
# print(f"Expected tensor size:{tensor_size/gb:0.1f}GB, cuda free:{mem_free_cuda/gb:0.1f}GB "
# f"torch free:{mem_free_torch/gb:0.1f} total:{mem_free_total/gb:0.1f} steps:{steps}")
if steps > 64:
max_res = math.floor(math.sqrt(math.sqrt(mem_free_total / 2.5)) / 8) * 64
raise RuntimeError(f'Not enough memory, use lower resolution (max approx. {max_res}x{max_res}). '
f'Need: {mem_required / 64 / gb:0.1f}GB free, Have:{mem_free_total / gb:0.1f}GB free')
slice_size = q.shape[1] // steps if (q.shape[1] % steps) == 0 else q.shape[1]
for i in range(0, q.shape[1], slice_size):
end = i + slice_size
s1 = einsum('b i d, b j d -> b i j', q[:, i:end], k)
# OURS: apply weights to attention
if weights is not None:
bias = weights.to(s1.dtype).log().clamp(min=torch.finfo(s1.dtype).min)
s1 = s1 + bias
del bias
s2 = s1.softmax(dim=-1, dtype=q.dtype)
del s1
r1[:, i:end] = einsum('b i j, b j d -> b i d', s2, v)
del s2
del q, k, v
r1 = r1.to(dtype)
r2 = rearrange(r1, '(b h) n d -> b n (h d)', h=h)
del r1
return self.to_out(r2)