hakmem/docs/analysis/PHASE89_SSOT_MEASUREMENT.md

# Phase 89 SSOT Measurement Capture

**Timestamp**: 2025-12-18 23:06:01  
**Git SHA**: e4c5f0535  
**Branch**: master  

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## Step 1: OBSERVE Binary (Telemetry Verification)

**Binary**: `./bench_random_mixed_hakmem_observe`  
**Profile**: `MIXED_TINYV3_C7_SAFE`  
**Iterations**: 20,000,000  
**Working Set**: 400  

**Inline Slots Overflow Stats (Preflight Verification)**:
- PUSH TOTAL: 4,812,031 ops (C4+C5+C6 verified active)
- POP TOTAL: 4,812,031 ops
- PUSH FULL: 0 (0.00%)
- POP EMPTY: 168 (0.003%)
- LEGACY FALLBACK CALLS: 5,327,294
- Judgment: ✓ \[C\] LEGACY used AND C4/C5/C6 INLINE SLOTS ACTIVE
- Throughput (with telemetry): **51.52M ops/s**

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## Step 2: Standard Build (Clean Performance Baseline)

**Binary**: `./bench_random_mixed_hakmem`  
**Build Flags**: RELEASE, no telemetry, standard optimization  
**Profile**: `MIXED_TINYV3_C7_SAFE`  
**Iterations**: 20,000,000  
**Working Set**: 400  
**Runs**: 10  

**10-Run Results**:
| Run | Throughput | Status |
|-----|-----------|--------|
| 1 | 51.15M | OK |
| 2 | 51.44M | OK |
| 3 | 51.61M | OK |
| 4 | 51.73M | Peak |
| 5 | 50.74M | Low |
| 6 | 51.34M | OK |
| 7 | 50.74M | Low |
| 8 | 51.37M | OK |
| 9 | 51.39M | OK |
| 10 | 51.31M | OK |

**Statistics**:
- **Mean**: 51.36M ops/s
- **Min**: 50.74M ops/s
- **Max**: 51.73M ops/s
- **Range**: 0.99M ops/s
- **CV**: ~0.7%

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## Step 3: FAST PGO Build (Optimized Performance Tracking)

**Binary**: `./bench_random_mixed_hakmem_minimal_pgo`  
**Build Flags**: RELEASE, PGO optimized, BENCH_MINIMAL=1  
**Profile**: `MIXED_TINYV3_C7_SAFE`  
**Iterations**: 20,000,000  
**Working Set**: 400  
**Runs**: 10  

**10-Run Results**:
| Run | Throughput | Status |
|-----|-----------|--------|
| 1 | 55.13M | Peak |
| 2 | 54.73M | High |
| 3 | 53.81M | OK |
| 4 | 54.60M | High |
| 5 | 55.02M | Peak |
| 6 | 52.89M | Low |
| 7 | 53.61M | OK |
| 8 | 53.53M | OK |
| 9 | 55.08M | Peak |
| 10 | 53.51M | OK |

**Statistics**:
- **Mean**: 54.16M ops/s
- **Min**: 52.89M ops/s
- **Max**: 55.13M ops/s
- **Range**: 2.24M ops/s
- **CV**: ~1.5%

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## Performance Delta Analysis

**Standard vs FAST PGO**:
- Delta: 54.16M - 51.36M = **2.80M ops/s**
- Percentage Gain: (2.80M / 51.36M) × 100 = **5.45%**

**Interpretation**:
- FAST PGO is 5.45% faster than Standard build
- This represents the optimization ceiling with current profile-guided configuration
- SSOT baseline for bottleneck analysis: **Standard 51.36M ops/s**

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## Environment Configuration (SSOT Locked)

**Key ENV variables** (forced in `scripts/run_mixed_10_cleanenv.sh`):
- `HAKMEM_BENCH_MIN_SIZE=16` - SSOT: prevent size drift
- `HAKMEM_BENCH_MAX_SIZE=1040` - SSOT: prevent class filtering
- `HAKMEM_BENCH_C5_ONLY=0` - SSOT: no single-class mode
- `HAKMEM_BENCH_C6_ONLY=0` - SSOT: no single-class mode
- `HAKMEM_BENCH_C7_ONLY=0` - SSOT: no single-class mode
- `HAKMEM_WARM_POOL_SIZE=16` - Phase 69 winner
- `HAKMEM_TINY_C4_INLINE_SLOTS=1` - Phase 76-1 promoted
- `HAKMEM_TINY_C5_INLINE_SLOTS=1` - Phase 75-2 promoted
- `HAKMEM_TINY_C6_INLINE_SLOTS=1` - Phase 75-1 promoted
- `HAKMEM_TINY_INLINE_SLOTS_FIXED=1` - Phase 78-1 promoted
- `HAKMEM_TINY_INLINE_SLOTS_SWITCHDISPATCH=1` - Phase 80-1 promoted
- `HAKMEM_TINY_INLINE_SLOTS_SWITCHDISPATCH_FIXED=0` - Phase 83-1 NO-GO
- `HAKMEM_FASTLANE_DIRECT=1` - Phase 19-1b promoted
- `HAKMEM_FREE_TINY_FAST_MONO_DUALHOT=1` - Phase 9/10 promoted
- `HAKMEM_FREE_TINY_FAST_MONO_LEGACY_DIRECT=1` - Phase 10 promoted
- `HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE` - default route

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## System Configuration

- **CPU**: AMD Ryzen 7 5825U with Radeon Graphics
- **Cores**: 16
- **Memory**: MemTotal:       13166508 kB
- **Kernel**: 6.8.0-87-generic

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## Next Steps (Phase 89 Step 5)

**Objective**: Identify top 3 bottleneck candidates using perf measurement
- Run `perf top` during Mixed SSOT execution
- Analyze top 50 functions by CPU time
- Filter to high-frequency code paths (avoid 0.001% optimizations)
- Prepare recommendations for Phase 90+