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>
97 lines
3.0 KiB
C
97 lines
3.0 KiB
C
// pagefault_telemetry_box.h - Box PageFaultTelemetry: Tiny page-touch visualization
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// Purpose:
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// - Approximate「何枚のページをどれだけ触ったか」をクラス別に計測する箱。
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// - Tiny フロントエンド側からのみ呼び出し、Superslab/カーネル側の挙動は変更しない。
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//
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// Design:
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// - 4KB ページ単位でアドレスを正規化し、簡易 Bloom/ビットセットにハッシュ。
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// - 1 クラスあたり 1024bit (= 16 x uint64_t) を用意し、popcount で「近似ページ枚数」を算出。
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// - 衝突は起こり得るが「下限近似値」として十分。目的は傾向把握。
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//
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// ENV Control:
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// - HAKMEM_TINY_PAGEFAULT_TELEMETRY=1 … 計測有効化
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// - HAKMEM_TINY_PAGEFAULT_DUMP=1 … 終了時に stderr へ 1 回だけダンプ
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#ifndef HAK_BOX_PAGEFAULT_TELEMETRY_H
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#define HAK_BOX_PAGEFAULT_TELEMETRY_H
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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// Tiny クラス数(既存定義が無ければ 8 とみなす)
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#ifndef TINY_NUM_CLASSES
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#define TINY_NUM_CLASSES 8
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#endif
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// ドメインバケット定義:
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// 0..7 : Tiny C0..C7
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// 8 : Mid Pool (hak_pool_*)
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// 9 : L25 Pool (hak_l25_pool_*)
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// 10 : Shared SuperSlab meta / backing
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// 11 : 予備
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enum {
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PF_BUCKET_TINY_BASE = 0,
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PF_BUCKET_TINY_LIMIT = TINY_NUM_CLASSES,
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PF_BUCKET_MID = TINY_NUM_CLASSES,
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PF_BUCKET_L25 = TINY_NUM_CLASSES + 1,
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PF_BUCKET_SS_META = TINY_NUM_CLASSES + 2,
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PF_BUCKET_RESERVED = TINY_NUM_CLASSES + 3,
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PF_BUCKET_MAX = TINY_NUM_CLASSES + 4
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};
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// ビットセット本体(1 バケットあたり 1024bit)
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extern __thread uint64_t g_pf_bloom[PF_BUCKET_MAX][16];
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// タッチ総数(ページ単位ではなく「呼び出し回数」)
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extern __thread uint64_t g_pf_touch[PF_BUCKET_MAX];
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// ENV による有効/無効判定(キャッシュ付き)
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int pagefault_telemetry_enabled(void);
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// 集計・ダンプ(ENV HAKMEM_TINY_PAGEFAULT_DUMP=1 のときだけ出力)
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void pagefault_telemetry_dump(void);
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// ----------------------------------------------------------------------------
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// Inline helper: ページタッチ記録
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// ----------------------------------------------------------------------------
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static inline void pagefault_telemetry_touch(int cls, const void* ptr) {
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#if HAKMEM_DEBUG_COUNTERS
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if (!pagefault_telemetry_enabled()) {
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return;
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}
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if (cls < 0 || cls >= PF_BUCKET_MAX) {
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return;
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}
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// 4KB ページに正規化
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uintptr_t addr = (uintptr_t)ptr;
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uintptr_t page = addr >> 12;
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// 1024 エントリのビットセットにハッシュ
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uint32_t idx = (uint32_t)(page & 1023u);
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uint32_t word = idx >> 6;
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uint32_t bit = idx & 63u;
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uint64_t mask = (uint64_t)1u << bit;
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uint64_t old = g_pf_bloom[cls][word];
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if (!(old & mask)) {
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g_pf_bloom[cls][word] = old | mask;
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}
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g_pf_touch[cls]++;
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#else
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(void)cls;
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(void)ptr;
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#endif
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}
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#ifdef __cplusplus
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}
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#endif
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#endif // HAK_BOX_PAGEFAULT_TELEMETRY_H
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