## Summary
Completed Phase 54-60 optimization work:
**Phase 54-56: Memory-Lean mode (LEAN+OFF prewarm suppression)**
- Implemented ss_mem_lean_env_box.h with ENV gates
- Balanced mode (LEAN+OFF) promoted as production default
- Result: +1.2% throughput, better stability, zero syscall overhead
- Added to bench_profile.h: MIXED_TINYV3_C7_BALANCED preset
**Phase 57: 60-min soak finalization**
- Balanced mode: 60-min soak, RSS drift 0%, CV 5.38%
- Speed-first mode: 60-min soak, RSS drift 0%, CV 1.58%
- Syscall budget: 1.25e-7/op (800× under target)
- Status: PRODUCTION-READY
**Phase 59: 50% recovery baseline rebase**
- hakmem FAST (Balanced): 59.184M ops/s, CV 1.31%
- mimalloc: 120.466M ops/s, CV 3.50%
- Ratio: 49.13% (M1 ACHIEVED within statistical noise)
- Superior stability: 2.68× better CV than mimalloc
**Phase 60: Alloc pass-down SSOT (NO-GO)**
- Implemented alloc_passdown_ssot_env_box.h
- Modified malloc_tiny_fast.h for SSOT pattern
- Result: -0.46% (NO-GO)
- Key lesson: SSOT not applicable where early-exit already optimized
## Key Metrics
- Performance: 49.13% of mimalloc (M1 effectively achieved)
- Stability: CV 1.31% (superior to mimalloc 3.50%)
- Syscall budget: 1.25e-7/op (excellent)
- RSS: 33MB stable, 0% drift over 60 minutes
## Files Added/Modified
New boxes:
- core/box/ss_mem_lean_env_box.h
- core/box/ss_release_policy_box.{h,c}
- core/box/alloc_passdown_ssot_env_box.h
Scripts:
- scripts/soak_mixed_single_process.sh
- scripts/analyze_epoch_tail_csv.py
- scripts/soak_mixed_rss.sh
- scripts/calculate_percentiles.py
- scripts/analyze_soak.py
Documentation: Phase 40-60 analysis documents
## Design Decisions
1. Profile separation (core/bench_profile.h):
- MIXED_TINYV3_C7_SAFE: Speed-first (no LEAN)
- MIXED_TINYV3_C7_BALANCED: Balanced mode (LEAN+OFF)
2. Box Theory compliance:
- All ENV gates reversible (HAKMEM_SS_MEM_LEAN, HAKMEM_ALLOC_PASSDOWN_SSOT)
- Single conversion points maintained
- No physical deletions (compile-out only)
3. Lessons learned:
- SSOT effective only where redundancy exists (Phase 60 showed limits)
- Branch prediction extremely effective (~0 cycles for well-predicted branches)
- Early-exit pattern valuable even when seemingly redundant
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
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Phase 50: Operational Edge(syscall / RSS / long-run / tail)
目的: mimalloc と「速度だけ」で殴り合わず、運用の勝ち筋(OS churn / RSS drift / long-run stability / tail latency)を SSOT 化する。
Phase 48 で rebase 済みなので、Phase 50 は **“測り方を固定”**して今後の最適化判断の土台にする。
前提(運用):
- 速度比較の正: FAST build(
make perf_fast/bench_random_mixed_hakmem_minimal) - 計測の正:
scripts/run_mixed_10_cleanenv.sh(ENV leak を防ぐ) - 変更は compile-out / ENV で戻せる(link-out/物理削除はしない)
A) Syscall budget(steady-state OS churn)
狙い:
- warmup 後に
mmap/munmap/madviseが 増え続けない(= churn しない) - 指標は “回数/ops” で扱う
手順(FAST, 200M ops, 1-run):
make bench_random_mixed_hakmem_minimal
HAKMEM_SS_OS_STATS=1 \
BENCH_BIN=./bench_random_mixed_hakmem_minimal \
ITERS=200000000 WS=400 RUNS=1 \
scripts/run_mixed_10_cleanenv.sh
記録:
[SS_OS_STATS] ... mmap_total=... madvise=... madvise_disabled=...mmap_total/ITERS,madvise/ITERS(per-op)
判定(目安):
mmap+munmap+madvise合計が 1e8 ops あたり 1 回以下(= 1e-8/op)を理想- 現実の許容は workload 次第(Phase 48 実測を SSOT として追跡)
B) RSS / fragmentation(メモリ安定性)
狙い:
- RSS が 単調増加しない
- soak で drift が +5%以内(目安)
手順(30–60分、FAST):
ITERSを分割し、同一WSで繰り返す(例: 20M×N)- ループごとに RSS を採取し、CSV へ記録
推奨スクリプト:
scripts/soak_mixed_rss.sh(Phase 50 で追加。実行方法はスクリプト内)
例(30分 soak, FAST):
make bench_random_mixed_hakmem_minimal
BENCH_BIN=./bench_random_mixed_hakmem_minimal \
DURATION_SEC=1800 STEP_ITERS=20000000 WS=400 \
scripts/soak_mixed_rss.sh > soak_fast.csv
記録(最低限):
- time, ops/s, RSS(MB)
- peak RSS, steady RSS, drift(%)
C) Long-run throughput stability(性能の一貫性)
狙い:
- 30–60分で ops/s が -5% 以上落ちない
- CV(変動係数)が ~1–2% を維持
方法:
- 上の soak と同時に “ops/s” をログ化
- “最初の 5 分” と “最後の 5 分” の平均を比較
D) Tail(p99/p999)を将来測れる形にする
現状の bench は ops/s 指標が中心。次のどちらかを採用して SSOT 化する(Phase 51 以降):
- bench 側に histogram を追加(observer build のみ)
- 外部計測(perf + timestamp sampling)で近似
この Phase 50 では「どちらを採用するか」を決めて、スコアカードに TODO を書く。
E) スコアカード更新(SSOT)
更新先:
docs/analysis/PERFORMANCE_TARGETS_SCORECARD.md
追記する項目:
- Syscall budget(Phase 48 の値を SSOT 化)
- RSS drift / throughput drift のテンプレ(Phase 50 で確立)