hakmem/PHASE8_INDEX.md

# Phase 8 Comprehensive Benchmark - Report Index

**Completion Date**: 2025-11-30
**Benchmark Status**: COMPLETE (30/30 runs successful)
**Next Phase**: Phase 9 - SuperSlab Deep Dive

## Quick Navigation

### Start Here
- **[PHASE8_EXECUTIVE_SUMMARY.md](PHASE8_EXECUTIVE_SUMMARY.md)** - Management overview, decisions needed
- **[PHASE8_QUICK_REFERENCE.md](PHASE8_QUICK_REFERENCE.md)** - Developer TL;DR, one-page summary

### Detailed Analysis
- **[PHASE8_VISUAL_SUMMARY.md](PHASE8_VISUAL_SUMMARY.md)** - Charts, graphs, decision matrix
- **[PHASE8_TECHNICAL_ANALYSIS.md](PHASE8_TECHNICAL_ANALYSIS.md)** - Root cause deep dive (8.8K)
- **[PHASE8_COMPREHENSIVE_BENCHMARK_REPORT.md](PHASE8_COMPREHENSIVE_BENCHMARK_REPORT.md)** - Full statistics

### Raw Data
- **[phase8_comprehensive_benchmark_results.txt](phase8_comprehensive_benchmark_results.txt)** - All 30 benchmark runs (222 lines)

## Key Findings (30-second read)

```
Working Set 256 (Hot Cache):
  HAKMEM:    79.2 M ops/s
  System:    86.7 M ops/s  (+9.4% faster)
  mimalloc: 114.9 M ops/s  (+45.2% faster)

Working Set 8192 (Realistic):
  HAKMEM:    16.5 M ops/s  ⚠️ CRITICAL
  System:    57.1 M ops/s  (+246% faster)
  mimalloc:  96.5 M ops/s  (+485% faster)

Scalability:
  HAKMEM degrades 4.80x (WS256 → WS8192)  🔴 BROKEN
  System degrades 1.52x                    ✅ Good
  mimalloc degrades 1.19x                  ✅ Excellent
```

**Critical Issue**: SuperSlab architecture does not scale beyond hot cache.

## What to Read Based on Your Role

### For Project Managers
1. Read: PHASE8_EXECUTIVE_SUMMARY.md (5 min)
2. Decision needed: Approve Phase 9 investigation (2 weeks, targeted fixes)
3. Backup plan: Hybrid Architecture if Phase 9 fails (adds 3 weeks)

### For Developers
1. Read: PHASE8_QUICK_REFERENCE.md (2 min)
2. Read: PHASE8_VISUAL_SUMMARY.md (5 min)
3. Prepare for: Phase 9 profiling and optimization work

### For Performance Engineers
1. Read: PHASE8_TECHNICAL_ANALYSIS.md (15 min)
2. Review: phase8_comprehensive_benchmark_results.txt (raw data)
3. Focus on: SuperSlab scaling issues, cache/TLB misses

### For Architects
1. Read: PHASE8_TECHNICAL_ANALYSIS.md (15 min)
2. Read: PHASE8_VISUAL_SUMMARY.md (decision matrix)
3. Evaluate: Hybrid Architecture option if Phase 9 fails

## Reproducibility

All benchmarks can be reproduced:

```bash
# HAKMEM Phase 8
./bench_random_mixed_hakmem 10000000 256    # Hot cache
./bench_random_mixed_hakmem 10000000 8192   # Realistic

# System malloc
./bench_random_mixed_system 10000000 256
./bench_random_mixed_system 10000000 8192

# mimalloc
./bench_random_mixed_mi 10000000 256
./bench_random_mixed_mi 10000000 8192
```

Each benchmark was run 5 times. Standard deviation < 2.5% for all runs.

## Report File Sizes

| File | Size | Read Time |
|------|------|-----------|
| PHASE8_EXECUTIVE_SUMMARY.md | 7.5K | 8 min |
| PHASE8_QUICK_REFERENCE.md | 3.2K | 3 min |
| PHASE8_VISUAL_SUMMARY.md | 7.2K | 7 min |
| PHASE8_TECHNICAL_ANALYSIS.md | 8.8K | 15 min |
| PHASE8_COMPREHENSIVE_BENCHMARK_REPORT.md | 4.9K | 5 min |
| phase8_comprehensive_benchmark_results.txt | 11K | N/A (raw data) |
| **Total** | **42.6K** | **38 min** |

## Critical Actions Required

### Immediate (This Week)
- [ ] Review PHASE8_EXECUTIVE_SUMMARY.md
- [ ] Approve Phase 9 investigation budget (2 weeks)
- [ ] Assign developer resources for profiling work

### Week 1 (Phase 9 Investigation)
- [ ] Add profiling instrumentation (cache/TLB misses)
- [ ] Analyze "shared_fail→legacy" root cause
- [ ] Measure SuperSlab fragmentation at different working sets
- [ ] Benchmark alternative SuperSlab sizes (1MB, 2MB, 4MB)

### Week 2 (Phase 9 Fixes)
- [ ] Implement hash table for SuperSlab lookup
- [ ] Fix shared slab capacity issues
- [ ] Optimize fast path (inline, reduce branches)
- [ ] Re-run benchmarks, evaluate results

### Decision Point (End of Week 2)
- [ ] If WS8192 >35 M ops/s: Continue optimization (Phases 10-12)
- [ ] If WS8192 <30 M ops/s: Switch to Hybrid Architecture (Phases 10-14)

## Success Metrics

### Phase 9 Minimum (Required)
- WS256: 79.2 → 85+ M ops/s (+7%)
- WS8192: 16.5 → 35+ M ops/s (+112%)
- Degradation: 4.80x → 2.50x or better

### Phase 12 Target (Production Ready)
- WS256: 90+ M ops/s (match System malloc)
- WS8192: 45+ M ops/s (80% of System malloc)
- Degradation: <2.0x (competitive)

## Timeline

```
Week 0  (Now):        Phase 8 COMPLETE
Week 1-2:             Phase 9 - Investigation + Fixes
Week 3:               Decision Point
Week 4-7 (Best):      Optimization → Production Ready
Week 4-9 (Likely):    Hybrid Architecture → Production Ready
Week 4-12 (Worst):    Complete Rewrite → Production Ready
```

## Questions?

- Technical questions → See PHASE8_TECHNICAL_ANALYSIS.md
- Performance questions → See PHASE8_COMPREHENSIVE_BENCHMARK_REPORT.md
- Strategic questions → See PHASE8_EXECUTIVE_SUMMARY.md
- Quick answers → See PHASE8_QUICK_REFERENCE.md

---

**Prepared by**: Automated Benchmark System
**Executed on**: 2025-11-30 06:04-06:07 JST
**Location**: /mnt/workdisk/public_share/hakmem/
**Status**: All deliverables complete, Phase 9 ready to begin