Skip to content

no fa3 with attention mask #163

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
weiyilwy merged 2 commits into from
Sep 4, 2025
Merged

no fa3 with attention mask #163

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f5441ef
no fa3 with attention mask
akaitsuki-ii Sep 4, 2025
72c1204
modify log level for fla attn_mask
Sep 4, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 7 additions & 4 deletions diffsynth_engine/models/basic/attention.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -135,12 +135,13 @@ def attention(
flash_attn3_compatible = q.shape[-1] <= FA3_MAX_HEADDIM
if attn_impl is None or attn_impl == "auto":
if FLASH_ATTN_3_AVAILABLE:
if flash_attn3_compatible:
if flash_attn3_compatible and attn_mask is None:
return flash_attn3(q, k, v, softmax_scale=scale)
else:
logger.warning(
f"head_dim={q.shape[-1]}, but flash_attn_3 only supports head dimension at most {FA3_MAX_HEADDIM}, will use fallback attention implementation"
)
if not flash_attn3_compatible:
logger.warning(f"head_dim={q.shape[-1]}, but flash_attn_3 only supports head dimension at most {FA3_MAX_HEADDIM}, will use fallback attention implementation")
else:
logger.debug("flash_attn_3 does not support attention mask, will use fallback attention implementation")
if XFORMERS_AVAILABLE:
return xformers_attn(q, k, v, attn_mask=attn_mask, scale=scale)
if SDPA_AVAILABLE:
Expand All @@ -156,6 +157,8 @@ def attention(
raise RuntimeError(
f"head_dim={q.shape[-1]}, but flash_attn_3 only supports head dimension at most {FA3_MAX_HEADDIM}"
)
if attn_mask is not None:
raise RuntimeError("flash_attn_3 does not support attention mask")
return flash_attn3(q, k, v, softmax_scale=scale)
if attn_impl == "flash_attn_2":
return flash_attn2(q, k, v, softmax_scale=scale)
Expand Down