Add a ModelAttentionBackend node to manually select the attention for models in the workflows. Currently supports pytorch attention or comfy kitchen attention.
Add --use-ck-attention to enable comfy kitchen attention as the default attention backend for all models (might break some).
Mirrors the decode fix: encode_tiled is identical to encode for
handles_tiling VAEs, so the OOM-retry path needs to free other models'
memory the same way decode's retry path already does.
For VAEs that set handles_tiling (MiniMax H3 video, SeedVR2), the tiled
decode fallback ends up calling the exact same decode path as the
regular decode that just OOM'd, so retrying without changing anything
about available memory just fails identically. Free memory held by
other loaded models (including dynamically streamed weights) before
the retry, keeping only the VAE itself loaded, so the retry actually
has a chance to succeed.
This avoids name collision (circular imports) for external custom nodes,
for which the comfy path is pushed into sys.path so Python's own logging module
is shadowed otherwise.
fixes: #15229
This priority scheme was broken in the case where you have pin
registration exhaustion while loading a VBAR that gets a big evicition.
The weight would stay in the loaded set but inherit the MRU priority
against other workflow models WRT pin registration which leads to async
offload without pinning.
Fix by universally promiting active pin registration above workflow
pins without concern for the weights/weights-loaded split. This diverges
from the actual budgeting where the split still makes sense.
Changes:
Remove sequential scan hint
Prefer NVML pressure on windows
Add async malloc clamp option (unused by comfy so far)
Workaround AMD windows GPU virtual address space leak
The largest change is the NVML pressure, which works around a cuMemGetInfo
drift from actual VRAM in some circumstances.
Windows has proven this logic works for a long time and there are
corner cases where this materialization actual consumes real RAM
on linux.
Its not as bad as the original windows commit charge surge, but
its still a detectable transient leak. So simplify and unify.
chelsealong
Jukka Seppänen
Barish Ozbay
comfyanonymous
rattus
Alexander Brown
Alex Harper
Alexis Rolland
blepping
endman100
rivadart
Oliver Freyermuth