Qwen3_VisionTransformer derived its compute device from
patch_embed.proj.weight and fed pos_embed.weight straight into the
position-embedding interpolation kernel, so the last two anchor weights
had to stay in VRAM for a tower to be streamable at all.
Record the device the tower was built on before the offloader moves
anything, and fall back to it when no weight is on the accelerator.
Move the interpolation table to that device per encode, which costs one
8.4 MiB host-to-device copy for a 456 MiB tower. Towers now leave no
parameters in VRAM between encodes; only small buffers such as the fused
input norm and rotary inv_freq remain.
Also let a tower restrict streaming through tower_offload_children, and
warn when a tower resolves its device property to another device type,
so a tower that reads an anchor weight reports the cause instead of a
Triton pointer error.
Co-authored-by: Hinata <hinata@idihore.id>
Signed-off-by: MOVZX <movzx@yahoo.com>
Add --offload-towers: place multimodal tower weights in pinned host
memory and bulk-copy each unit to the GPU only during its forward,
keeping towers out of VRAM between encodes. Unlike UVA zero-copy,
whole-tensor H2D transfers avoid re-reading operand tiles over PCIe
inside the GEMM inner loop. Tower streaming is independent of layer
group scheduling, so group_size may be 0 for tower-only offload.
Co-authored-by: Hinata <hinata@idihore.id>
Signed-off-by: MOVZX <movzx@yahoo.com>
MOVZXandHinata
Taneem Ibrahim