text_encoder_cpu_offload means params rest on CPU between calls but compute
on GPU: FSDP-wrapped encoders (T5/llama/clip) already get this via
CPUOffloadPolicy streaming, but encoders without _fsdp_shard_conditions
(reason1/Qwen2.5-VL) were parked on CPU and, after the encoder-device input
routing added for kandinsky5, silently ran their 7B forward on CPU (crashing
outright with flash-attn installed). Move plain CPU-parked encoders to the
target device for the forward and back afterwards, mirroring the
image-encoder/VAE offload pattern; FSDP (DTensor) encoders keep the existing
input routing. Revert the examples to text_encoder_cpu_offload=True now that
the default works. Verified e2e: T2V/I2V outputs are metric-identical to
GPU-resident runs, with ~12GB lower VRAM during denoising.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
text_encoder_cpu_offload=True makes the Qwen encoder compute on CPU, where
flash-attn has no kernels; with flash_attn installed both examples crash in
the first text-encoding forward. The offloaded path only worked in envs
without flash_attn via the silent SDPA fallback.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
