Artificial Intelligence
23 Sep 2026
5 min read
PagedAttention Maps Logical KV Blocks to Noncontiguous Physical Memory
An autoregressive request grows its KV cache as tokens arrive, but its final sequence length is not known when decoding begins. Reserving one contiguous region for the maximum possible sequence length ties memory to capacity that may never be used. PagedAttention changes that allocation boundary: a sequence is represented as logical KV blocks, while a block table maps those logical blocks to physical blocks that need not be adjacent in GPU memory.