GLM 5.3 Optimizations, Part 1: Hybrid HiSparse Offloading in vLLM

vLLM introduces Hybrid HiSparse offloading to optimize GLM 5.3 inference on memory-constrained hardware. The technique keeps active KV cache on GPU while offloading inactive tokens to CPU, enabling full context length support on single nodes. This improves concurrency for agentic workloads without requiring re-prefilling, addressing a key bottleneck in serving large models efficiently.