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Author SHA1 Message Date
Moe Charm (CI)
03ba62df4d Phase 23 Unified Cache + PageFaultTelemetry generalization: Mid/VM page-fault bottleneck identified 
Summary:
- Phase 23 Unified Cache: +30% improvement (Random Mixed 256B: 18.18M → 23.68M ops/s)
- PageFaultTelemetry: Extended to generic buckets (C0-C7, MID, L25, SSM)
- Measurement-driven decision: Mid/VM page-faults (80-100K) >> Tiny (6K) → prioritize Mid/VM optimization

Phase 23 Changes:
1. Unified Cache implementation (core/front/tiny_unified_cache.{c,h})
   - Direct SuperSlab carve (TLS SLL bypass)
   - Self-contained pop-or-refill pattern
   - ENV: HAKMEM_TINY_UNIFIED_CACHE=1, HAKMEM_TINY_UNIFIED_C{0-7}=128

2. Fast path pruning (tiny_alloc_fast.inc.h, tiny_free_fast_v2.inc.h)
   - Unified ON → direct cache access (skip all intermediate layers)
   - Alloc: unified_cache_pop_or_refill() → immediate fail to slow
   - Free: unified_cache_push() → fallback to SLL only if full

PageFaultTelemetry Changes:
3. Generic bucket architecture (core/box/pagefault_telemetry_box.{c,h})
   - PF_BUCKET_{C0-C7, MID, L25, SSM} for domain-specific measurement
   - Integration: hak_pool_try_alloc(), l25_alloc_new_run(), shared_pool_allocate_superslab_unlocked()

4. Measurement results (Random Mixed 500K / 256B):
   - Tiny C2-C7: 2-33 pages, high reuse (64-3.8 touches/page)
   - SSM: 512 pages (initialization footprint)
   - MID/L25: 0 (unused in this workload)
   - Mid/Large VM benchmarks: 80-100K page-faults (13-16x higher than Tiny)

Ring Cache Enhancements:
5. Hot Ring Cache (core/front/tiny_ring_cache.{c,h})
   - ENV: HAKMEM_TINY_HOT_RING_ENABLE=1, HAKMEM_TINY_HOT_RING_C{0-7}=size
   - Conditional compilation cleanup

Documentation:
6. Analysis reports
   - RANDOM_MIXED_BOTTLENECK_ANALYSIS.md: Page-fault breakdown
   - RANDOM_MIXED_SUMMARY.md: Phase 23 summary
   - RING_CACHE_ACTIVATION_GUIDE.md: Ring cache usage
   - CURRENT_TASK.md: Updated with Phase 23 results and Phase 24 plan

Next Steps (Phase 24):
- Target: Mid/VM PageArena/HotSpanBox (page-fault reduction 80-100K → 30-40K)
- Tiny SSM optimization deferred (low ROI, ~6K page-faults already optimal)
- Expected improvement: +30-50% for Mid/Large workloads

Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>
 2025-11-17 02:47:58 +09:00
Moe Charm (CI)
eb12044416 Phase 21-1-C: Ring cache Refill/Cascade + Metrics - SLL → Ring cascade 
**実装内容**:
- Alloc miss → refill: ring_refill_from_sll() (32 blocks from TLS SLL)
- Free full → fallback: 既に Phase 21-1-B で実装済み（Ring full → TLS SLL）
- Metrics 追加: hit/miss/push/full/refill カウンタ（Phase 19-1 スタイル）
- Stats 出力: ring_cache_print_stats() を bench_random_mixed.c から呼び出し

**修正内容**:
- tiny_alloc_fast.inc.h: Ring miss 時に ring_refill_from_sll() 呼び出し、retry
- tiny_ring_cache.h: Metrics カウンタ追加（pop/push で更新）
- tiny_ring_cache.c: tls_sll_box.h をインクルード、refill カウンタ追加
- bench_random_mixed.c: ring_cache_print_stats() 呼び出し

**ENV 変数**:
- HAKMEM_TINY_HOT_RING_ENABLE=1: Ring 有効化
- HAKMEM_TINY_HOT_RING_CASCADE=1: Refill 有効化（SLL → Ring）
- HAKMEM_TINY_HOT_RING_C2=128: C2 サイズ（default: 128）
- HAKMEM_TINY_HOT_RING_C3=128: C3 サイズ（default: 128）

**動作確認**:
- Ring ON + CASCADE ON: 836K ops/s (10K iterations) ✅
- クラッシュなし、正常動作

**次のステップ**: Phase 21-1-D (A/B テスト)
 2025-11-16 08:15:30 +09:00
Moe Charm (CI)
db9c06211e Phase 21-1-A: Ring cache 基本実装 - Array-based TLS cache (C2/C3) 
## Summary
Phase 21-1-A の基本実装完了。Ring buffer ベースの TLS cache を C2/C3
（33-128B）専用に実装。ポインタチェイス削減で +15-20% 性能向上を目指す。

## Implementation

**Files Created**:
- `core/front/tiny_ring_cache.h` - Ring cache API, ENV control
- `core/front/tiny_ring_cache.c` - Ring cache implementation

**Makefile Integration**:
- Added `core/front/tiny_ring_cache.o` to OBJS_BASE
- Added `core/front/tiny_ring_cache_shared.o` to SHARED_OBJS
- Added `core/front/tiny_ring_cache.o` to BENCH_HAKMEM_OBJS_BASE

## Design (Task 先生調査結果 + ChatGPT フィードバック)

**Ring Buffer Structure**:
- C2/C3 専用（hot classes, 33-128B）
- Default 128 slots (power-of-2, ENV で 64/128/256 A/B 可能)
- Ultra-fast pop/push (1-2 instructions, array access)
- Fast modulo via mask (capacity - 1)

**Hierarchy** (Option 4: UltraHot 置き換え):
```
Ring (L0, C2/C3 専用) → HeapV2 (L1, fallback) → TLS SLL (L2) → SuperSlab (L3)
```

**Rationale**:
- UltraHot の C3 問題（5.8% hit rate）を根本解決
- Phase 19-3 の +12.9%（UltraHot 除去）を維持
- Ring サイズ（128）>> UltraHot（4）→ hit rate 大幅向上期待

**Performance Goal**:
- Pointer chasing: TLS SLL 1 回 → Ring 0 回
- Memory access: 3 → 2 回
- Cache locality: 配列（連続メモリ）vs linked list
- Expected: +15-20% (54.4M → 62-65M ops/s)

## ENV Variables

```bash
HAKMEM_TINY_HOT_RING_ENABLE=1  # Ring 有効化 (default: 0)
HAKMEM_TINY_HOT_RING_C2=128    # C2 サイズ (default: 128)
HAKMEM_TINY_HOT_RING_C3=128    # C3 サイズ (default: 128)
HAKMEM_TINY_HOT_RING_CASCADE=1 # SLL → Ring refill (default: 0)
```

## Implementation Status

Phase 21-1-A: ✅ **COMPLETE**
- Ring buffer data structure
- TLS variables
- ENV control (enable/capacity)
- Power-of-2 capacity (fast modulo)
- Ultra-fast pop/push inline functions
- Refill from SLL (scaffold)
- Init/shutdown/stats (scaffold)
- Makefile integration
- Compile success

Phase 21-1-B: ⏳ **NEXT** - Alloc/Free 統合
Phase 21-1-C: ⏳ **PENDING** - Refill/Cascade 実装
Phase 21-1-D: ⏳ **PENDING** - A/B テスト

## Next Steps

1. Alloc path 統合 (`core/tiny_alloc_fast.inc.h`)
2. Free path 統合 (`core/tiny_free_fast_v2.inc.h`)
3. Init call from `hakmem_tiny.c`
4. A/B test: Ring vs UltraHot vs Baseline

🎯 Target: 62-65M ops/s (+15-20% vs 54.4M baseline)

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

Co-Authored-By: Claude <noreply@anthropic.com>
 2025-11-16 07:32:24 +09:00