How PagedAttention Works: Paging the KV Cache Like an Operating System

Why serving LLMs fragments GPU memory, and how vLLM’s PagedAttention fixes it with OS-style paging: physical blocks, a block table, chained block hashes, and a walkthrough of how blocks are allocated, shared, freed and evicted.

Date: November 3, 2026  |  Estimated Reading Time: 11 min  |  Author: Chi Zhang