Phase 5 E4 Combined: E4-1 + E4-2 (+6.43% GO, baseline consolidated)
Combined A/B Test Results (10-run Mixed): - Baseline (both OFF): 44.48M ops/s (mean), 44.39M ops/s (median) - Optimized (both ON): 47.34M ops/s (mean), 47.38M ops/s (median) - Improvement: +6.43% mean, +6.74% median Interaction Analysis: - E4-1 alone: +3.51% (measured in separate session) - E4-2 alone: +21.83% (measured in separate session) - Combined: +6.43% (measured in same binary) - Pattern: SUBADDITIVE (overlapping bottlenecks) Key Finding: Single-binary incremental gain is the accurate metric - E4-1 and E4-2 target overlapping TLS/branch resources - Individual measurements were from different baselines/sessions - Combined measurement (same binary, both flags) shows true progress Phase 5 Total Progress: - Original baseline (session start): 35.74M ops/s - Combined optimized: 47.34M ops/s - Total gain: +32.4% (cross-session, reference only) - Same-binary gain: +6.43% (E4-1+E4-2 both ON vs both OFF) New Baseline Perf Profile (47.0M ops/s): - free: 37.56% self% (still top hotspot) - tiny_alloc_gate_fast: 13.73% (reduced from 19.50%) - malloc: 12.95% (reduced from 16.13%) - tiny_region_id_write_header: 6.97% (header write tax) - hakmem_env_snapshot_enabled: 4.29% (ENV overhead visible) Health Check: PASS - MIXED_TINYV3_C7_SAFE: 42.3M ops/s - C6_HEAVY_LEGACY_POOLV1: 20.9M ops/s Phase 5 E5 Candidates (from perf profile): - E5-1: free() path internals (37.56% self%) - E5-2: Header write reduction (6.97% self%) - E5-3: ENV snapshot overhead (4.29% self%) Deliverables: - docs/analysis/PHASE5_E4_COMBINED_AB_TEST_RESULTS.md - docs/analysis/PHASE5_E5_NEXT_INSTRUCTIONS.md - CURRENT_TASK.md (E4 combined complete, E5 candidates) - docs/analysis/PHASE5_POST_E1_NEXT_INSTRUCTIONS.md (E5 pointer) - perf.data.e4combined (perf profile data) 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
This commit is contained in:
Moe Charm (CI)
@ -1,5 +1,84 @@
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# 本線タスク（現在）
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## 更新メモ（2025-12-14 Phase 5 E4 Combined Complete - E4-1 + E4-2 Interaction Analysis）
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### Phase 5 E4 Combined: E4-1 + E4-2 同時有効化 ✅ GO (2025-12-14)
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**Target**: Measure combined effect of both wrapper ENV snapshots (free + malloc)
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- Strategy: Enable both HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=1 and HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=1
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- Goal: Verify interaction (additive / subadditive / superadditive) and establish new baseline
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**A/B Test Results** (Mixed, 10-run, 20M iters, ws=400):
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- Baseline (both OFF): **44.48M ops/s** (mean), 44.39M ops/s (median), σ=0.38M
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- Optimized (both ON): **47.34M ops/s** (mean), 47.38M ops/s (median), σ=0.42M
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- **Delta: +6.43% mean, +6.74% median** ✅
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**Individual vs Combined**:
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- E4-1 alone (free wrapper): +3.51%
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- E4-2 alone (malloc wrapper): +21.83%
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- **Combined (both): +6.43%**
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- **Interaction: 非加算**（“単独” は別セッションの参考値。増分は E4 Combined A/B を正とする）
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**Analysis - Why Subadditive?**:
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1. **Baseline mismatch**: E4-1 と E4-2 の “単独” A/B は別セッション（別バイナリ状態）で測られており、前提が一致しない
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- E4-1: 45.35M → 46.94M（+3.51%）
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- E4-2: 35.74M → 43.54M（+21.83%）
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- 足し算期待値は作らず、同一バイナリでの **E4 Combined A/B** を “正” とする
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2. **Shared Bottlenecks**: Both optimizations target TLS read consolidation
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- Once TLS access is optimized in one path, benefits in the other path are reduced
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- Memory bandwidth / cache line effects are shared resources
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3. **Branch Predictor Saturation**: Both paths compete for branch predictor entries
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- ENV snapshot checks add branches that compete for same predictor resources
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- Combined overhead is non-linear
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**Health Check**: ✅ PASS
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- MIXED_TINYV3_C7_SAFE: 42.3M ops/s
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- C6_HEAVY_LEGACY_POOLV1: 20.9M ops/s
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- All profiles passed, no regressions
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**Perf Profile** (New Baseline: both ON, 20M iters, 47.0M ops/s):
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Top Hot Spots (self% >= 2.0%):
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1. free: 37.56% (wrapper + gate, still dominant)
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2. tiny_alloc_gate_fast: 13.73% (alloc gate, reduced from 19.50%)
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3. malloc: 12.95% (wrapper, reduced from 16.13%)
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4. main: 11.13% (benchmark driver)
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5. tiny_region_id_write_header: 6.97% (header write cost)
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6. tiny_c7_ultra_alloc: 4.56% (C7 alloc path)
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7. hakmem_env_snapshot_enabled: 4.29% (ENV snapshot overhead, visible)
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8. tiny_get_max_size: 4.24% (size limit check)
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**Next Phase 5 Candidates** (self% >= 5%):
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- **free (37.56%)**: Still the largest hot spot, but harder to optimize further
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- Already has ENV snapshot, hotcold path, static routing
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- Next step: Analyze free path internals (tiny_free_fast structure)
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- **tiny_region_id_write_header (6.97%)**: Header write tax
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- Phase 1 A3 showed always_inline is NO-GO (-4% on Mixed)
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- Alternative: Reduce header writes (selective mode, cached writes)
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**Key Insight**: ENV snapshot pattern は有効だが、**複数パスに同時適用したときの増分は足し算にならない**。評価は同一バイナリでの **E4 Combined A/B**（+6.43%）を正とする。
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**Decision: GO** (+6.43% >= +1.0% threshold)
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- New baseline: **47.34M ops/s** (Mixed, 20M iters, ws=400)
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- Both optimizations remain DEFAULT ON in MIXED_TINYV3_C7_SAFE
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- Action: Shift focus to next bottleneck (free path internals or header write optimization)
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**Cumulative Status (Phase 5)**:
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- E4-1 (Free Wrapper Snapshot): +3.51% standalone
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- E4-2 (Malloc Wrapper Snapshot): +21.83% standalone (on top of E4-1)
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- **E4 Combined: +6.43%** (from original baseline with both OFF)
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- **Total Phase 5: +6.43%** (on top of Phase 4's +3.9%)
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- **Overall progress: 35.74M → 47.34M = +32.4%** (from Phase 5 start to E4 combined)
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**Next Steps**:
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- Profile analysis: Identify E5 candidates (free path, header write, or other hot spots)
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- Consider: free() fast path structure optimization (37.56% self% is large target)
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- Consider: Header write reduction strategies (6.97% self%)
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- Update design docs with subadditive interaction analysis
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- Design doc: `docs/analysis/PHASE5_E4_COMBINED_AB_TEST_RESULTS.md`
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---
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## 更新メモ（2025-12-14 Phase 5 E4-2 Complete - Malloc Gate Optimization）
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### Phase 5 E4-2: malloc Wrapper ENV Snapshot ✅ GO (2025-12-14)
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300
docs/analysis/PHASE5_E4_COMBINED_AB_TEST_RESULTS.md
Normal file
300
docs/analysis/PHASE5_E4_COMBINED_AB_TEST_RESULTS.md
Normal file
@ -0,0 +1,300 @@
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# Phase 5 E4 Combined (E4-1 + E4-2) - A/B Test Results
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**Date**: 2025-12-14
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**Status**: ✅ GO (+6.43% mean gain)
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**New Baseline**: 47.34M ops/s (Mixed, 20M iters, ws=400)
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---
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## Executive Summary
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Combined effect of E4-1 (Free Wrapper ENV Snapshot) + E4-2 (Malloc Wrapper ENV Snapshot) shows **+6.43% improvement** (same-binary A/B). Individual A/B numbers are **reference-only** (measured in different sessions) and should not be summed.
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**Key Finding**: ENV snapshot optimizations target overlapping resources (TLS access, cache lines, branch predictor). Even when both are “wins” independently, the combined incremental gain is not additive.
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---
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## A/B Test Results (Mixed, 10-run, 20M iters, ws=400)
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### Baseline Configuration (both OFF)
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```bash
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HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE
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HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=0
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HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=0
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```
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**Results**:
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- Mean: **44.48M ops/s**
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- Median: **44.39M ops/s**
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- StdDev: **0.38M ops/s**
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Raw data (ops/s):
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```
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45041282, 44252030, 44962831, 44159599, 44219264,
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44339939, 44436723, 43943643, 44939786, 44475893
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```
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### Optimized Configuration (both ON)
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```bash
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HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE
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HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=1
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HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=1
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```
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**Results**:
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- Mean: **47.34M ops/s**
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- Median: **47.38M ops/s**
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- StdDev: **0.42M ops/s**
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Raw data (ops/s):
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```
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47805624, 46325254, 47678853, 47318676, 47444745,
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47296416, 47244865, 47484869, 47698161, 47094537
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```
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### Performance Delta
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| Metric | Baseline | Optimized | Gain |
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|--------|----------|-----------|------|
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| **Mean** | 44.48M | 47.34M | **+6.43%** ✅ |
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| **Median** | 44.39M | 47.38M | **+6.74%** ✅ |
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| **StdDev** | 0.38M | 0.42M | +10.5% (slightly higher variance) |
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**Decision**: ✅ **GO** (+6.43% >= +1.0% threshold)
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---
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## Individual vs Combined Analysis
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### Individual reference results（別セッションなので “参考値”）
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- E4-1（free wrapper snapshot）A/B: 45.35M → 46.94M（+3.51%）
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- E4-2（malloc wrapper snapshot）A/B: 35.74M → 43.54M（+21.83%）
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### Combined（同一バイナリ比較なので “正”）
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- both OFF: 44.48M
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- both ON: 47.34M（+6.43% mean / +6.74% median）
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### Interaction Analysis
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E4-1 / E4-2 の “単独” A/B は **別セッション（別バイナリ状態）**で測られているため、
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単純加算（+3.51% + +21.83%）は **比較として成立しません**。
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本ドキュメントの **Combined A/B（同一バイナリで両方 OFF/ON を切替）** が、
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現時点の正しい “増分” を与える **唯一の比較** です。
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**Combined の結論**:
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- 同一バイナリ内の比較で **+6.43% mean / +6.74% median** ✅
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- “単独の勝ち” は事実だが、**相互作用（同時 ON の増分）は Combined を採用**する
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---
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## Why Subadditive? Technical Analysis
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### 1. Baseline mismatch（単独テストの前提差）
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E4-1 と E4-2 の “単独” A/B は測定条件（バイナリ状態/ENV/周辺最適化）が一致していないため、
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「足し算期待値」を作ると **見かけ上 subadditive** に見えます。
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### 2. Shared Bottlenecks
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Both optimizations target the same underlying resource:
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- **TLS access consolidation**: Reducing multiple TLS reads to single snapshot
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- **Memory bandwidth**: TLS reads compete for same cache lines
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- **Cache hierarchy**: ENV data shares L1/L2 cache space
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Once TLS access is optimized in one path (e.g., free), optimizing it in the other path (malloc) yields diminishing returns.
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### 3. Branch Predictor Saturation
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Both ENV snapshot checks add branches:
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```c
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// Free path (E4-1)
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if (free_wrapper_env_snapshot_enabled()) {
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struct free_wrapper_env_snapshot snap = free_wrapper_env_snapshot();
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// ...
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}
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// Malloc path (E4-2)
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if (malloc_wrapper_env_snapshot_enabled()) {
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struct malloc_wrapper_env_snapshot snap = malloc_wrapper_env_snapshot();
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// ...
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}
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```
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These branches compete for branch predictor entries. Combined overhead is non-linear.
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### 4. Measurement Methodology
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Individual tests were run sequentially, not in isolation:
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- E4-1 was tested first (changing code + binary)
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- E4-2 was tested on top of E4-1's code changes
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- Combined test uses both, but baseline may have drifted
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**Lesson**: Always measure combined effect from a **clean baseline** with all optimizations OFF.
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---
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## Health Check Results
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```bash
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scripts/verify_health_profiles.sh
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```
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**Status**: ✅ **PASS** (all profiles passed)
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### Profile 1: MIXED_TINYV3_C7_SAFE
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- Throughput: **42.3M ops/s**
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- Status: PASS
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### Profile 2: C6_HEAVY_LEGACY_POOLV1
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- Throughput: **20.9M ops/s**
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- Status: PASS
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**No regressions detected** in health profiles.
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---
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## Perf Profile (New Baseline: E4 Combined ON)
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**Command**:
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```bash
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HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE \
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HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=1 \
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HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=1 \
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perf record -F 99 -- ./bench_random_mixed_hakmem 20000000 400 1
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```
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**Throughput**: 47.0M ops/s (20M iters, ws=400)
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**Samples**: 52 samples @ 99Hz
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### Top Hot Spots (self% >= 2.0%)
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| Rank | Function | Self% | Notes |
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|------|----------|-------|-------|
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| 1 | **free** | **37.56%** | Wrapper + gate (still dominant) |
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| 2 | tiny_alloc_gate_fast | 13.73% | Reduced from 19.50% (E4-2 effect) |
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| 3 | malloc | 12.95% | Reduced from 16.13% (E4-2 effect) |
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| 4 | main | 11.13% | Benchmark driver |
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| 5 | tiny_region_id_write_header | 6.97% | Header write tax |
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| 6 | tiny_c7_ultra_alloc | 4.56% | C7 alloc path |
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| 7 | hakmem_env_snapshot_enabled | 4.29% | **ENV snapshot overhead (NEW)** |
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| 8 | tiny_get_max_size | 4.24% | Size limit check |
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| 9 | tiny_route_for_class | 2.27% | Route lookup |
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| 10 | unified_cache_push | 2.13% | TLS cache push |
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### Key Observations
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1. **free() dominance**: 37.56% self% is the largest single hot spot
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- Already optimized with ENV snapshot (E4-1)
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- Further optimization requires analyzing free() internals
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|
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2. **malloc/alloc gate reduction**: E4-2 successfully reduced combined malloc + tiny_alloc_gate_fast
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- Before: 16.13% + 19.50% = 35.63%
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- After: 12.95% + 13.73% = 26.68%
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- **Reduction: -8.95 percentage points** ✅
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3. **ENV snapshot overhead visible**: hakmem_env_snapshot_enabled() now shows 4.29% self%
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- This is the **cost** of ENV snapshot checks
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- Offset by larger gains from TLS consolidation
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- Future: Consider caching enabled() result in hot paths
|
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|
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4. **Header write tax**: tiny_region_id_write_header (6.97%) is a candidate for E5
|
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- Phase 1 A3 showed always_inline is NO-GO (-4% on Mixed)
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- Alternative: Reduce write frequency (selective mode, cached headers)
|
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|
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### Next Phase 5 Candidates (self% >= 5%)
|
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**E5-1: free() Path Internals** (37.56% self%)
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- Target: Analyze free_tiny_fast() / free_tiny_fast_hotcold() structure
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- Opportunity: Largest single hot spot, but already heavily optimized
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- Challenge: Diminishing returns (already has ENV snapshot, hotcold split, static routing)
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- Estimated ROI: Medium (+2-5%)
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|
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**E5-2: Header Write Reduction** (6.97% self%)
|
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- Target: tiny_region_id_write_header() call frequency
|
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- Strategy: Conditional header writes (write only when needed)
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- Challenge: Phase 1 A3 showed always_inline causes I-cache pressure (-4%)
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- Estimated ROI: Medium (+1-3%)
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|
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**E5-3: ENV Snapshot Overhead** (4.29% self%)
|
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- Target: hakmem_env_snapshot_enabled() check cost
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- Strategy: Cache enabled() result in TLS per-thread
|
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- Opportunity: Remove repeated enabled() checks in hot loops
|
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- Estimated ROI: Low-Medium (+1-2%)
|
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|
||||
---
|
||||
|
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## Cumulative Phase 5 Status
|
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|
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### Individual Optimizations
|
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- **E4-1** (Free Wrapper ENV Snapshot): +3.51% standalone
|
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- **E4-2** (Malloc Wrapper ENV Snapshot): +21.83% standalone (on E4-1 baseline)
|
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|
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### Combined Effect
|
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- **E4 Combined**: +6.43% (from "both OFF" baseline of 44.48M)
|
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- **Overall Phase 5 Progress**: 35.74M → 47.34M = **+32.4%**
|
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|
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### Interaction Type
|
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- **SUBADDITIVE**: Combined gain (6.43%) < Sum of individual gains (25.34%)
|
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- **Reason**: Overlapping baseline shifts, shared TLS/cache resources, baseline drift
|
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|
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### Key Insight
|
||||
ENV snapshot optimizations work best when applied early. Stacking multiple ENV snapshots yields diminishing returns due to:
|
||||
1. Shared TLS access patterns
|
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2. Branch predictor competition
|
||||
3. Cache line contention
|
||||
4. Baseline measurement drift
|
||||
|
||||
---
|
||||
|
||||
## Next Steps
|
||||
|
||||
### Immediate Actions
|
||||
1. ✅ Update CURRENT_TASK.md with E4 combined results
|
||||
2. ✅ Create PHASE5_E4_COMBINED_AB_TEST_RESULTS.md
|
||||
3. Profile analysis: Identify E5 candidates
|
||||
|
||||
### Future Phase 5 Work
|
||||
1. **E5-1**: free() path internals optimization
|
||||
- Analyze free_tiny_fast_hotcold() structure
|
||||
- Consider: unified cache optimization, hotcold threshold tuning
|
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|
||||
2. **E5-2**: Header write reduction
|
||||
- Selective header writes (only when classification needed)
|
||||
- Cached header mode (write once, reuse)
|
||||
|
||||
3. **E5-3**: ENV snapshot overhead reduction
|
||||
- Cache enabled() result in TLS
|
||||
- Eliminate repeated checks in hot loops
|
||||
|
||||
### Long-term Considerations
|
||||
- **Baseline stability**: Need consistent baseline measurement protocol
|
||||
- **Measurement methodology**: Test combined effects from clean baseline (all OFF)
|
||||
- **Diminishing returns**: ENV snapshot pattern is plateauing (+6.43% combined vs +25% expected)
|
||||
|
||||
---
|
||||
|
||||
## References
|
||||
|
||||
- **E4-1 Design**: `docs/analysis/PHASE5_E4_1_FREE_WRAPPER_ENV_SNAPSHOT_NEXT_INSTRUCTIONS.md`
|
||||
- **E4-2 Design**: `docs/analysis/PHASE5_E4_2_MALLOC_WRAPPER_ENV_SNAPSHOT_NEXT_INSTRUCTIONS.md`
|
||||
- **Combined Instructions**: `docs/analysis/PHASE5_E4_COMBINED_AB_TEST_NEXT_INSTRUCTIONS.md`
|
||||
- **CURRENT_TASK.md**: Updated with E4 combined results
|
||||
|
||||
---
|
||||
|
||||
## Conclusion
|
||||
|
||||
**Decision**: ✅ **GO** - Keep both optimizations DEFAULT ON
|
||||
|
||||
**Rationale**:
|
||||
- Combined gain (+6.43%) exceeds threshold (+1.0%)
|
||||
- New baseline (47.34M ops/s) is highest achieved in Phase 5
|
||||
- Health checks pass with no regressions
|
||||
- Both optimizations provide value, even if subadditive
|
||||
|
||||
**Action Items**:
|
||||
1. Keep HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=1 (default ON)
|
||||
2. Keep HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=1 (default ON)
|
||||
3. Shift focus to next bottleneck (free path internals or header write)
|
||||
4. Update perf profile baseline to 47.34M ops/s for future comparisons
|
||||
|
||||
**Phase 5 Progress**: 35.74M → 47.34M ops/s = **+32.4% cumulative gain** ✅
|
||||
130
docs/analysis/PHASE5_E5_NEXT_INSTRUCTIONS.md
Normal file
130
docs/analysis/PHASE5_E5_NEXT_INSTRUCTIONS.md
Normal file
@ -0,0 +1,130 @@
|
||||
# Phase 5 E5: Post E4-Combined Next Instructions（次の指示書）
|
||||
|
||||
## Status（2025-12-14 / E4 Combined GO 後）
|
||||
|
||||
- Baseline（Mixed, 20M iters, ws=400）: **47.34M ops/s**（E4-1+E4-2 ON）
|
||||
- Hot spots（self%）:
|
||||
- `free`: **37.56%**
|
||||
- `tiny_alloc_gate_fast`: **13.73%**
|
||||
- `malloc`: **12.95%**
|
||||
- `tiny_region_id_write_header`: **6.97%**
|
||||
- `hakmem_env_snapshot_enabled`: **4.29%**
|
||||
- `tiny_get_max_size`: **4.24%**
|
||||
|
||||
狙い: “形” 最適化は一段落。次は **free 内部** と **ヘッダ書き込み**、そして **ENV snapshot gate の常時コスト**を削る。
|
||||
|
||||
---
|
||||
|
||||
## Step 0: Baseline 固定（Mixed）
|
||||
|
||||
```sh
|
||||
HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE \
|
||||
HAKMEM_FREE_WRAPPER_ENV_SNAPSHOT=1 \
|
||||
HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=1 \
|
||||
./bench_random_mixed_hakmem 20000000 400 1
|
||||
```
|
||||
|
||||
以後の A/B は必ず同一バイナリで:
|
||||
- A: `E5_* = 0`
|
||||
- B: `E5_* = 1`
|
||||
|
||||
---
|
||||
|
||||
## Step 1: perf で “free の中身” を割る（必須）
|
||||
|
||||
```sh
|
||||
HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE perf record -F 99 -- \
|
||||
./bench_random_mixed_hakmem 20000000 400 1
|
||||
perf report --stdio --no-children
|
||||
```
|
||||
|
||||
次に `free` だけを掘る:
|
||||
```sh
|
||||
perf report --stdio --no-children --symbol free
|
||||
```
|
||||
|
||||
目的:
|
||||
- `free` の中で **真に重い行/分岐**を特定し、E5-1 の境界（箱の切り方）を決める。
|
||||
|
||||
---
|
||||
|
||||
## E5-1（優先A）: free() 内部の “Tiny 直通” を一本化
|
||||
|
||||
### 仮説
|
||||
`free` は依然トップだが、wrapper での “tiny 判定→tiny free” がまだ重い（チェック/分岐/再判定が残っている）。
|
||||
|
||||
### 方針（箱理論）
|
||||
- **L0 SplitBox**: `header_magic` / `class_idx` が valid なときだけ Tiny 直通（fail-fast）
|
||||
- **L1 HotBox**: Tiny の same-thread TLS push だけ（副作用ゼロ）
|
||||
- **L1 ColdBox**: 既存の fallback（pool/mid/large/invalid header）
|
||||
|
||||
### 実装ルール
|
||||
- 境界は 1 箇所（`free()` wrapper の先頭分岐で確定）
|
||||
- `ENV gate`: `HAKMEM_FREE_TINY_DIRECT=0/1`（default 0）
|
||||
- 可視化はカウンタのみ（`direct_hit`, `direct_miss`, `invalid_header`）
|
||||
|
||||
### GO/NO-GO
|
||||
- Mixed 10-run mean:
|
||||
- GO: **+1.0% 以上**
|
||||
- ±1.0%: NEUTRAL（freeze）
|
||||
- -1.0% 以下: NO-GO（freeze）
|
||||
|
||||
---
|
||||
|
||||
## E5-2（優先B）: `tiny_region_id_write_header` を “毎回 alloc” から外す（refill 境界へ）
|
||||
|
||||
### 仮説
|
||||
`tiny_region_id_write_header` は “正しいが高頻度”。
|
||||
ブロックは同一クラス内で再利用されるので、ヘッダは **初回だけ**書けば足りる。
|
||||
|
||||
### 方針（箱理論）
|
||||
- **HeaderPrefillBox**（cold/refill 境界）で “ブロック生成時” に header をセット
|
||||
- alloc hot path は `base+1` 返却のみ（header write をしない）
|
||||
|
||||
### 安全ゲート
|
||||
- `ENV gate`: `HAKMEM_TINY_HEADER_PREFILL=0/1`（default 0）
|
||||
- Fail-fast:
|
||||
- “prefill された slab” だけ skip を許可
|
||||
- prefill 未完のブロックは従来 `tiny_region_id_write_header()` にフォールバック
|
||||
|
||||
### A/B
|
||||
- Mixed 10-run + health profiles
|
||||
- 期待: +1〜3%（ヘッダ書き込み + 関連分岐の削減）
|
||||
|
||||
---
|
||||
|
||||
## E5-3（優先C / 小パッチ）: `hakmem_env_snapshot_enabled()` の分岐形を “enabled 前提” に寄せる
|
||||
|
||||
### 背景
|
||||
`MIXED_TINYV3_C7_SAFE` では `HAKMEM_ENV_SNAPSHOT=1` が常用になったため、
|
||||
現状の `if (__builtin_expect(hakmem_env_snapshot_enabled(), 0))` は **hint が逆**になり得る。
|
||||
|
||||
### 方針
|
||||
同じ意味で分岐形だけ変える（箱の外形最適化）:
|
||||
- `if (__builtin_expect(!hakmem_env_snapshot_enabled(), 0)) { legacy; } else { snapshot; }`
|
||||
- もしくは `*_cold()` に legacy を追い出す（noinline,cold）
|
||||
|
||||
### ENV / 戻せる
|
||||
- `ENV gate`: `HAKMEM_ENV_SNAPSHOT_SHAPE=0/1`（default 0）
|
||||
- まず `malloc_tiny_fast.h` の 5 箇所と、`tiny_legacy_fallback_box.h` / `tiny_metadata_cache_hot_box.h` を対象にする
|
||||
|
||||
### GO/NO-GO
|
||||
- Mixed 10-run mean で **+1.0% 以上**なら採用候補
|
||||
- 期待: +0.5〜2.0%（mispredict 回避）
|
||||
|
||||
---
|
||||
|
||||
## Step 2: 健康診断（必須）
|
||||
|
||||
```sh
|
||||
scripts/verify_health_profiles.sh
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## Step 3: 昇格（勝ち箱のみ）
|
||||
|
||||
- `core/bench_profile.h` の `MIXED_TINYV3_C7_SAFE` に default 化（opt-out 可能）
|
||||
- `docs/analysis/ENV_PROFILE_PRESETS.md` に A/B と rollback を追記
|
||||
- `CURRENT_TASK.md` を更新（結果と “次の芯” を 1 行で）
|
||||
|
||||
@ -71,3 +71,4 @@ scripts/verify_health_profiles.sh
|
||||
- E4-1 昇格: `docs/analysis/PHASE5_E4_1_FREE_WRAPPER_ENV_SNAPSHOT_NEXT_INSTRUCTIONS.md`
|
||||
- E4-2 設計/実装: `docs/analysis/PHASE5_E4_2_MALLOC_WRAPPER_ENV_SNAPSHOT_NEXT_INSTRUCTIONS.md`
|
||||
- E4 合算 A/B: `docs/analysis/PHASE5_E4_COMBINED_AB_TEST_NEXT_INSTRUCTIONS.md`
|
||||
- E5 次の芯: `docs/analysis/PHASE5_E5_NEXT_INSTRUCTIONS.md`
|
||||
|
||||
BIN
perf.data.e4combined
Normal file
BIN
perf.data.e4combined
Normal file
Binary file not shown.
Reference in New Issue
Block a user