# Audit Performance

> Audit hot paths for performance inefficiencies (allocations, contention, layout)

- Skill: `ben-manes/audit-performance` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ben-manes/audit-performance`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ben-manes/audit-performance/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: ben-manes (https://skillmd.com/u/ben-manes)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/ben-manes/audit-performance

---


Audit the Caffeine cache for performance inefficiencies.

Context: Caffeine runs in high-throughput, low-latency JVM services where cache
operations occur millions of times per second. The library is already heavily
optimized — generic textbook advice is not useful.

## Rules

1. **Read the actual source code** before analyzing.
2. **Only report findings traceable to specific lines.**
3. **Account for JIT compilation.** C2 eliminates many apparent inefficiencies:
   escape analysis, inlining, dead code elimination. Don't flag JIT-optimized issues.
4. **Ignore correctness, style, and API design.** This is purely runtime performance.
5. **Quality over quantity.** Five real findings beat twenty speculative ones.

## Analysis Areas (priority order)

### 1. Get Fast Path (highest priority)
Trace get()/getIfPresent() from entry to return. Count volatile/opaque reads,
method calls, branches, allocations. Even one saved volatile read matters.

### 2. Allocation and GC Pressure
Identify allocations surviving escape analysis on hot paths. Frequency, size,
lifetime. Do not flag JIT-eliminated allocations.

### 3. Contention and Cache-Line Effects
CAS retry rates, cache-line bouncing, graceful vs catastrophic degradation
for read buffer, evictionLock, CHM bins, node field updates.

### 4. FrequencySketch
Counter layout locality, hash computation, reset cost. Accessed every read/write.

### 5. Maintenance Work
Worst-case work per write, latency spikes, eviction cascades, timer wheel scan cost.

### 6. Memory Layout
Node object size, pointer indirection depth, false sharing, @Contended opportunities.

## Output Format

For each finding:
```
## [Category] Title
**Location:** file:method (lines X-Y)
**Severity:** negligible | moderate | high
**What happens:** (trace the code path)
**Why it matters:** (quantify)
**JIT considerations:** (will C2 handle this?)
**Proposed fix:** (specific code change)
**Expected benchmark impact:** (JMH prediction)
```

If fewer than 3 real issues, the code is well-optimized. Do not pad the output.