Files
hakmem/docs/analysis/PHASE5_POST_E1_NEXT_INSTRUCTIONS.md
Moe Charm (CI) 5528612f2a Phase 5 E4-2: Malloc Wrapper ENV Snapshot (+21.83% GO, ADOPTED)
Target: Consolidate malloc wrapper TLS reads + eliminate function calls
- malloc (16.13%) + tiny_alloc_gate_fast (19.50%) = 35.63% combined
- Strategy: E4-1 success pattern + function call elimination

Implementation:
- ENV gate: HAKMEM_MALLOC_WRAPPER_ENV_SNAPSHOT=0/1 (default 0)
- core/box/malloc_wrapper_env_snapshot_box.{h,c}: New box
  - Consolidates multiple TLS reads → 1 TLS read
  - Pre-caches tiny_max_size() == 256 (eliminates function call)
  - Lazy init with probe window (bench_profile putenv sync)
- core/box/hak_wrappers.inc.h: Integration in malloc() wrapper
- Makefile: Add malloc_wrapper_env_snapshot_box.o to all targets

A/B Test Results (Mixed, 10-run, 20M iters):
- Baseline (SNAPSHOT=0): 35.74M ops/s (mean), 35.75M ops/s (median)
- Optimized (SNAPSHOT=1): 43.54M ops/s (mean), 43.92M ops/s (median)
- Improvement: +21.83% mean, +22.86% median (+7.80M ops/s)

Decision: GO (+21.83% >> +1.0% threshold, 21.8x over)
- Why 6.2x better than E4-1 (+3.51%)?
  - Higher malloc call frequency (allocation-heavy workload)
  - Function call elimination (tiny_max_size pre-cached)
  - Larger target: 35.63% vs free's 25.26%
- Health check: PASS (all profiles)
- Action: PROMOTED to MIXED_TINYV3_C7_SAFE preset

Phase 5 Cumulative (estimated):
- E1 (ENV Snapshot): +3.92%
- E4-1 (Free Wrapper Snapshot): +3.51%
- E4-2 (Malloc Wrapper Snapshot): +21.83%
- Estimated combined: ~+30% (needs validation)

Next Steps:
- Combined A/B test (E4-1 + E4-2 simultaneously)
- Measure actual cumulative effect
- Profile new baseline for next optimization targets

Deliverables:
- docs/analysis/PHASE5_E4_2_MALLOC_WRAPPER_ENV_SNAPSHOT_1_DESIGN.md
- docs/analysis/PHASE5_E4_2_MALLOC_WRAPPER_ENV_SNAPSHOT_1_AB_TEST_RESULTS.md
- docs/analysis/PHASE5_E4_2_MALLOC_WRAPPER_ENV_SNAPSHOT_NEXT_INSTRUCTIONS.md
- docs/analysis/PHASE5_E4_COMBINED_AB_TEST_NEXT_INSTRUCTIONS.md (next)
- docs/analysis/ENV_PROFILE_PRESETS.md (E4-2 added)
- CURRENT_TASK.md (E4-2 complete)
- core/bench_profile.h (E4-2 promoted to default)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-14 05:13:29 +09:00

2.0 KiB
Raw Blame History

Phase 5: Post-E1 Baseline & Next Target次の指示書

Status2025-12-14

  • Phase 4 の勝ち箱は E1ENV SnapshotMIXED_TINYV3_C7_SAFE で default 化)
  • E3-4ENV CTORNO-GO / freeze
  • Phase 5 の勝ち箱: E4-1free wrapper snapshotMIXED_TINYV3_C7_SAFE で default 化)
  • Phase 5 の勝ち箱: E4-2malloc wrapper snapshotMIXED_TINYV3_C7_SAFE で default 化)
  • 次は “形” ではなく 新 baseline で perf を取り直し、self% ≥ 5% の芯を殴る

Step 0: Baseline 固定Mixed

HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE ./bench_random_mixed_hakmem 20000000 400 1

注意:

  • 以後の A/B はこのプロファイル(=E1 ONを基準にする

Step 1: perf で “芯” を選ぶself% ≥ 5%

HAKMEM_PROFILE=MIXED_TINYV3_C7_SAFE perf record -F 99 -- \
  ./bench_random_mixed_hakmem 20000000 400 1
perf report --stdio --no-children

GO/NO-GO:

  • self% が 5% 未満の最適化は原則 NO-GOまず他を削る

Step 2: 研究箱の候補を 1 つに絞るBox Theory

要件:

  • L0 ENV gatedefault OFFを必ず用意戻せる
  • 境界は 1 箇所(変換点を増やさない)
  • 可視化はカウンタ 1 本まで(常時ログ禁止)

Step 3: A/B で GO 判定Mixed

Mixed 10-run:

  • GO: mean +1.0% 以上
  • ±1%: NEUTRALfreeze
  • -1% 以下: NO-GOfreeze

Step 4: 健康診断

scripts/verify_health_profiles.sh

Step 5: 昇格

  • 勝ち箱だけを core/bench_profile.h のプリセットへ
  • docs/analysis/ENV_PROFILE_PRESETS.md に結果rollback を追記
  • CURRENT_TASK.md を更新

Next

  • 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