CUDA layer for the paged-KV + swap work:
- csrc: new paged_attention.cu plus updates across attention/gemm/norm/
activation/embedding/reduce kernels and common.cuh.
- xserv-kernels: new dispatch module and kernel-binding updates.
- xserv-cuda: cudaMallocHost/FreeHost bindings + PinnedBuffer (host swap
pool backing) and offset-aware D2H/H2D copies used to move KV blocks
between the GPU pool and pinned host memory.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- GpuKVCache: pre-allocated GPU buffers, D2D copy append at offset
- Per-head strided layout [num_kv_heads, max_seq_len, head_dim]
- Fixed critical bug: seq_len must advance AFTER all layers write
(not inside the loop per-layer)
- GpuBuffer::copy_from_device_at for offset-based D2D copy
- Tensor::from_storage constructor for wrapping raw GPU buffers
- Exported Storage and Dims from xserv-tensor
Correctness: GPU KV cache vs CPU KV cache = 50/50 bit-identical
Performance: ~neutral (KV cache was never the main bottleneck —
reshape/merge/transpose CPU round-trips dominate for Qwen3-8B)
TTFT: 122ms, TBT: 142ms, 7.0 tok/s (marginal change from 7.3)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Cargo workspace with xserv-cuda crate
- CUDA FFI bindings (cudart: memory, stream, device, error)
- GpuBuffer RAII wrapper with H2D/D2H/D2D copy
- CudaStream wrapper with RAII Drop
- CachingAllocator with size-bucketed free lists
- PinnedBuffer for page-locked host memory
- Device info query via cudaDeviceGetAttribute
- Vector-add CUDA kernel smoke test
- Integration test suite (11 tests)
- build.rs: cc crate compiles .cu for SM 12.0
- sync-and-build.sh for remote build on dash5
- Roadmap doc (docs/00-roadmap.md) and Phase 0+1 design doc
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
