Merge remote-tracking branch 'takuma104/xformers-flash-attention' (3fa48207) · Commits · github_fork / Stable Diffusion Webui

modules/sd_hijack_optimizations.py

+24 −2

Original line number	Diff line number	Diff line
		@@ -290,7 +290,19 @@ def xformers_attention_forward(self, x, context=None, mask=None):

		q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> b n h d', h=h), (q_in, k_in, v_in))
		del q_in, k_in, v_in
		out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=None)

		if shared.cmd_opts.xformers_flash_attention:
		op = xformers.ops.MemoryEfficientAttentionFlashAttentionOp
		fw, bw = op
		if not fw.supports(xformers.ops.fmha.Inputs(query=q, key=k, value=v, attn_bias=None)):
		# print('xformers_attention_forward', q.shape, k.shape, v.shape)
		# Flash Attention is not availabe for the input arguments.
		# Fallback to default xFormers' backend.
		op = None
		else:
		op = None

		out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=None, op=op)

		out = rearrange(out, 'b n h d -> b n (h d)', h=h)
		return self.to_out(out)
		@@ -365,7 +377,17 @@ def xformers_attnblock_forward(self, x):
		q = q.contiguous()
		k = k.contiguous()
		v = v.contiguous()
		out = xformers.ops.memory_efficient_attention(q, k, v)
		if shared.cmd_opts.xformers_flash_attention:
		op = xformers.ops.MemoryEfficientAttentionFlashAttentionOp
		fw, bw = op
		if not fw.supports(xformers.ops.fmha.Inputs(query=q, key=k, value=v)):
		# print('xformers_attnblock_forward', q.shape, k.shape, v.shape)
		# Flash Attention is not availabe for the input arguments.
		# Fallback to default xFormers' backend.
		op = None
		else:
		op = None
		out = xformers.ops.memory_efficient_attention(q, k, v, op=op)
		out = rearrange(out, 'b (h w) c -> b c h w', h=h)
		out = self.proj_out(out)
		return x + out

modules/shared.py

+1 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,7 @@ parser.add_argument("--realesrgan-models-path", type=str, help="Path to director
		parser.add_argument("--clip-models-path", type=str, help="Path to directory with CLIP model file(s).", default=None)
		parser.add_argument("--xformers", action='store_true', help="enable xformers for cross attention layers")
		parser.add_argument("--force-enable-xformers", action='store_true', help="enable xformers for cross attention layers regardless of whether the checking code thinks you can run it; do not make bug reports if this fails to work")
		parser.add_argument("--xformers-flash-attention", action='store_true', help="enable xformers with Flash Attention to improve reproducibility (supported for SD2.x or variant only)")
		parser.add_argument("--deepdanbooru", action='store_true', help="does not do anything")
		parser.add_argument("--opt-split-attention", action='store_true', help="force-enables Doggettx's cross-attention layer optimization. By default, it's on for torch cuda.")
		parser.add_argument("--opt-sub-quad-attention", action='store_true', help="enable memory efficient sub-quadratic cross-attention layer optimization")

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