Inference & Serving · core

KV Caching & PagedAttention

Attention-state reuse, KV memory sizing, paging, fragmentation, prefix caching, eviction, and multi-tenant pressure.

inference-servingkv-cache

Mental model

The KV cache trades memory for avoided recomputation. PagedAttention maps logical token blocks to non-contiguous physical pages so variable-length requests waste less memory.

How to study KV Caching & PagedAttention

Begin by restating the mental model in your own words, then connect it to a concrete system you have built or operated. Name the mechanism, the constraint it addresses, and the trade-off it introduces. Use Efficient Memory Management for Large Language Model Serving with PagedAttention to check details, but close the source before writing your explanation. Retrieval is the learning step; rereading is only preparation.

Next, compare KV Caching & PagedAttention with vLLM & Inference Engines, Continuous Batching. Ask what changes in correctness, latency, resource use, operability, and failure recovery. Complete Design exercise: KV Caching & PagedAttention and preserve the command, input, output, and one failed attempt as evidence. Finish by explaining the idea without jargon to someone who has not studied the track.

Proof of understanding

  • Explain the mechanism from first principles and identify the state it reads or changes.
  • Give one situation where the concept is the right choice and one where it is not.
  • Predict a realistic failure mode before running the drill, then compare the prediction with evidence.
  • Connect the result to a roadmap or build artifact instead of treating the concept as isolated trivia.

Learn from primary sources

Practice and explain it back

Design exercise: KV Caching & PagedAttention

Attention-state reuse, KV memory sizing, paging, fragmentation, prefix caching, eviction, and multi-tenant pressure. Implement designOutline() returning non-empty values for: cacheSizing, pageMapping, evictionPolicy. Each value must name a concrete mechanism or decision.

Expected evidence: A design outline with cacheSizing, pageMapping, evictionPolicy plus an explicit failure mode or trade-off.

Open the interactive drill →

Review prompts

  • What fragmentation problem does PagedAttention solve, and what capability falls out of it for free?

Build evidence

Synthesize: Inference & Serving

Build a production mental model for inference engines, memory, kernels, routing, hardware, and serving economics. Produce one working system, benchmark, or evidence-backed design that integrates the path.

  • Implements or precisely models the core mechanisms from all three milestones
  • Includes at least one injected failure or adversarial case and demonstrates recovery
  • Reports quality, latency, resource, reliability, or usability measurements relevant to the domain
  • Ships a concise architecture note explaining decisions, trade-offs, and remaining risks

Prerequisites

Related concepts

Learning paths