Commit Graph

13 Commits

Author SHA1 Message Date
cbb35ee27f Phase 13 v1 + E5-2 retest: Both NEUTRAL, freeze as research boxes
Phase 13 v1: Header Write Elimination (C7 preserve header)
- Verdict: NEUTRAL (+0.78%)
- Implementation: HAKMEM_TINY_C7_PRESERVE_HEADER ENV gate (default OFF)
- Makes C7 nextptr offset conditional (0→1 when enabled)
- 4-point matrix A/B test results:
  * Case A (baseline): 51.49M ops/s
  * Case B (WRITE_ONCE=1): 52.07M ops/s (+1.13%)
  * Case C (C7_PRESERVE=1): 51.36M ops/s (-0.26%)
  * Case D (both): 51.89M ops/s (+0.78% NEUTRAL)
- Action: Freeze as research box (default OFF, manual opt-in)

Phase 5 E5-2: Header Write-Once retest (promotion test)
- Verdict: NEUTRAL (+0.54%)
- Motivation: Phase 13 Case B showed +1.13%, re-tested with dedicated 20-run
- Results (20-run):
  * Case A (baseline): 51.10M ops/s
  * Case B (WRITE_ONCE=1): 51.37M ops/s (+0.54%)
- Previous test: +0.45% (consistent with NEUTRAL)
- Action: Keep as research box (default OFF, manual opt-in)

Key findings:
- Header write tax optimization shows consistent NEUTRAL results
- Neither Phase 13 v1 nor E5-2 reaches GO threshold (+1.0%)
- Both implemented as reversible ENV gates for future research

Files changed:
- New: core/box/tiny_c7_preserve_header_env_box.{c,h}
- Modified: core/box/tiny_layout_box.h (C7 offset conditional)
- Modified: core/tiny_nextptr.h, core/box/tiny_header_box.h (comments)
- Modified: core/bench_profile.h (refresh sync)
- Modified: Makefile (add new .o files)
- Modified: scripts/run_mixed_10_cleanenv.sh (add C7_PRESERVE ENV)
- Docs: PHASE13_*, PHASE5_E5_2_HEADER_WRITE_ONCE_* (design/results)

Next: Phase 14 (Pointer-chase reduction, tcache-style intrusive LIFO)

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Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-15 00:32:25 +09:00
71b1354d32 Phase 10: FREE-TINY-FAST MONO LEGACY DIRECT (GO +1.89%)
Results:
- A/B test: +1.89% on Mixed (10-run, clean env)
- Baseline: 51.96M ops/s
- Optimized: 52.94M ops/s
- Improvement: +984K ops/s (+1.89%)
- C6-heavy verification: +7.86% (nonlegacy_mask works correctly, no misfires)

Strategy:
- Extend Phase 9 (C0-C3 DUALHOT) to C4-C7 LEGACY DIRECT
- Fail-Fast principle: Never misclassify MID/ULTRA/V7 as LEGACY
- nonlegacy_mask: Cached at init, hot path uses single bit operation

Success factors:
1. Performance improvement: +1.89% (1.9x GO threshold)
2. Safety verified: nonlegacy_mask prevents MID v3 misfire in C6-heavy
3. Phase 9 coexistence: C0-C3 (Phase 9) + C4-C7 (Phase 10) = full LEGACY coverage
4. Minimal overhead: Single bit operation in hot path (mask & (1u<<class))

Implementation:
- Patch 1: ENV gate box (free_tiny_fast_mono_legacy_direct_env_box.h)
  - ENV: HAKMEM_FREE_TINY_FAST_MONO_LEGACY_DIRECT=0/1 (default 0)
  - nonlegacy_mask cached (reuses free_policy_fast_v2_nonlegacy_mask())
  - Probe window: 64 (avoid bench_profile putenv race)
- Patch 2: Early-exit in free_tiny_fast() (malloc_tiny_fast.h)
  - Conditions: !nonlegacy_mask, route==LEGACY, !LARSON_FIX, done==1
  - Direct call: tiny_legacy_fallback_free_base()
- Patch 3: Visibility (free_path_stats_box.h)
  - mono_legacy_direct_hit counter (compile-out in release)
- Patch 4: cleanenv extension (run_mixed_10_cleanenv.sh)
  - ENV leak protection

Safety verification (C6-heavy):
- OFF: 19.75M ops/s
- ON: 21.30M ops/s (+7.86%)
- nonlegacy_mask correctly excludes C6 (MID v3 active)
- Improvement from C0-C5, C7 direct path acceleration

Files modified:
- core/bench_profile.h: add to MIXED_TINYV3_C7_SAFE preset
- core/front/malloc_tiny_fast.h: early-exit insertion
- core/box/free_path_stats_box.h: counter
- core/box/free_tiny_fast_mono_legacy_direct_env_box.h: NEW (ENV gate + nonlegacy_mask)
- scripts/run_mixed_10_cleanenv.sh: ENV leak protection

Health check: PASSED (all profiles)

Promotion: Added to MIXED_TINYV3_C7_SAFE preset (default ON, opt-out)

Rollback: HAKMEM_FREE_TINY_FAST_MONO_LEGACY_DIRECT=0

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Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-14 20:09:40 +09:00
871034da1f Phase 9: FREE-TINY-FAST MONO DUALHOT (GO +2.72%)
Results:
- A/B test: +2.72% on Mixed (10-run, clean env)
- Baseline: 48.89M ops/s
- Optimized: 50.22M ops/s
- Improvement: +1.33M ops/s (+2.72%)
- Stability: Standard deviation reduced by 60.8% (2.44M → 955K ops/s)

Strategy:
- Transplant C0-C3 "second hot" path to monolithic free_tiny_fast()
- Early-exit within monolithic (no hot/cold split)
- FastLane free now benefits from C0-C3 direct path

Success factors:
1. Performance improvement: +2.72% (2.7x GO threshold)
2. Stability improvement: 2.6x more stable (stdev 60.8% reduction)
3. Learned from Phase 7 failure:
   - Phase 7: Function split (hot/cold) → NO-GO
   - Phase 9: Early-exit within monolithic → GO
4. FastLane free compatibility: C0-C3 direct path now works with FastLane
5. Policy snapshot overhead reduction: C0-C3 (48% of Mixed) skip route lookup

Implementation:
- Patch 1: ENV gate box (free_tiny_fast_mono_dualhot_env_box.h)
  - ENV: HAKMEM_FREE_TINY_FAST_MONO_DUALHOT=0/1 (default 0)
  - Probe window: 64 (avoid bench_profile putenv race)
- Patch 2: Early-exit in free_tiny_fast() (malloc_tiny_fast.h)
  - Conditions: class_idx <= 3, !LARSON_FIX, route==LEGACY
  - Direct call: tiny_legacy_fallback_free_base()
- Patch 3: Visibility (free_path_stats_box.h)
  - mono_dualhot_hit counter (compile-out in release)
- Patch 4: cleanenv extension (run_mixed_10_cleanenv.sh)
  - ENV leak protection

Files modified:
- core/bench_profile.h: add to MIXED_TINYV3_C7_SAFE preset
- core/front/malloc_tiny_fast.h: early-exit insertion
- core/box/free_path_stats_box.h: counter
- core/box/free_tiny_fast_mono_dualhot_env_box.h: NEW (ENV gate)
- scripts/run_mixed_10_cleanenv.sh: ENV leak protection

Health check: PASSED (all profiles)

Promotion: Added to MIXED_TINYV3_C7_SAFE preset (default ON, opt-out)

Rollback: HAKMEM_FREE_TINY_FAST_MONO_DUALHOT=0

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Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-14 19:16:49 +09:00
6d38511318 Phase 5: E7 prune no-go (keep frozen boxes); add clean-env runner 2025-12-14 08:11:20 +09:00
21e2e4ac2b Phase 4 E3-4: ENV Constructor Init (+4.75% GO)
Target: Eliminate E1 lazy init check overhead (3.22% self%)
- E1 consolidated ENV gates but lazy check remained in hot path
- Strategy: __attribute__((constructor(101))) for pre-main init

Implementation:
- ENV gate: HAKMEM_ENV_SNAPSHOT_CTOR=0/1 (default 0, research box)
- core/box/hakmem_env_snapshot_box.c: Constructor function added
  - Reads ENV before main() when CTOR=1
  - Refresh also syncs gate state for bench_profile putenv
- core/box/hakmem_env_snapshot_box.h: Dual-mode enabled check
  - CTOR=1 fast path: direct global read (no lazy branch)
  - CTOR=0 fallback: legacy lazy init (rollback safe)
  - Branch hints adjusted for default OFF baseline

A/B Test Results (Mixed, 10-run, 20M iters, E1=1):
- Baseline (CTOR=0): 44.28M ops/s (mean), 44.60M ops/s (median)
- Optimized (CTOR=1): 46.38M ops/s (mean), 46.53M ops/s (median)
- Improvement: +4.75% mean, +4.35% median

Decision: GO (+4.75% >> +0.5% threshold)
- Expected +0.5-1.5%, achieved +4.75%
- Lazy init branch overhead was larger than expected
- Action: Keep as research box (default OFF), evaluate promotion

Phase 4 Cumulative:
- E1 (ENV Snapshot): +3.92%
- E2 (Alloc Per-Class): -0.21% (NEUTRAL, frozen)
- E3-4 (Constructor Init): +4.75%
- Total Phase 4: ~+8.5%

Deliverables:
- docs/analysis/PHASE4_E3_ENV_CONSTRUCTOR_INIT_DESIGN.md
- docs/analysis/PHASE4_E3_ENV_CONSTRUCTOR_INIT_NEXT_INSTRUCTIONS.md
- docs/analysis/PHASE4_COMPREHENSIVE_STATUS_ANALYSIS.md
- docs/analysis/PHASE4_EXECUTIVE_SUMMARY.md
- scripts/verify_health_profiles.sh (sanity check script)
- CURRENT_TASK.md (E3-4 complete, next instructions)

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Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
2025-12-14 02:57:35 +09:00
b51b600e8d Phase 4-Step1: Add PGO workflow automation (+6.25% performance)
Implemented automated Profile-Guided Optimization workflow using Box pattern:

Performance Improvement:
- Baseline:      57.0 M ops/s
- PGO-optimized: 60.6 M ops/s
- Gain: +6.25% (within expected +5-10% range)

Implementation:
1. scripts/box/pgo_tiny_profile_config.sh - 5 representative workloads
2. scripts/box/pgo_tiny_profile_box.sh - Automated profile collection
3. Makefile PGO targets:
   - pgo-tiny-profile: Build instrumented binaries
   - pgo-tiny-collect: Collect .gcda profile data
   - pgo-tiny-build:   Build optimized binaries
   - pgo-tiny-full:    Complete workflow (profile → collect → build → test)
4. Makefile help target: Added PGO instructions for discoverability

Design:
- Box化: Single responsibility, clear contracts
- Deterministic: Fixed seeds (42) for reproducibility
- Safe: Validation, error detection, timeout protection (30s/workload)
- Observable: Progress reporting, .gcda verification (33 files generated)

Workload Coverage:
- Random mixed: 3 working set sizes (128/256/512 slots)
- Tiny hot: 2 size classes (16B/64B)
- Total: 5 workloads covering hot/cold paths

Documentation:
- PHASE4_STEP1_COMPLETE.md - Completion report
- CURRENT_TASK.md - Phase 4 roadmap (Step 1 complete ✓)
- docs/design/PHASE4_TINY_FRONT_BOX_DESIGN.md - Complete Phase 4 design

Next: Phase 4-Step2 (Hot/Cold Path Box, target +10-15%)

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-29 11:28:38 +09:00
131cdb7b88 Doc: Add benchmark reports, atomic freelist docs, and .gitignore update
Phase 1 Commit: Comprehensive documentation and build system cleanup

Added Documentation:
- BENCHMARK_SUMMARY_20251122.md: Current performance baseline
- COMPREHENSIVE_BENCHMARK_REPORT_20251122.md: Detailed analysis
- LARSON_SLOWDOWN_INVESTIGATION_REPORT.md: Larson benchmark deep dive
- ATOMIC_FREELIST_*.md (5 files): Complete atomic freelist documentation
  - Implementation strategy, quick start, site-by-site guide
  - Index and summary for easy navigation

Added Scripts:
- run_comprehensive_benchmark.sh: Automated benchmark runner
- scripts/analyze_freelist_sites.sh: Freelist analysis tool
- scripts/verify_atomic_freelist_conversion.sh: Conversion verification

Build System:
- Updated .gitignore: Added *.d (build dependency files)
- Cleaned up tracked .d files (will be ignored going forward)

Performance Status (2025-11-22):
- Random Mixed 256B: 59.6M ops/s (VERIFIED WORKING)
- Benchmark command: ./out/release/bench_random_mixed_hakmem 10000000 256 42
- Known issue: workset=8192 causes SEGV (to be fixed separately)

Notes:
- bench_random_mixed.c already tracked, working state confirmed
- Ultra SLIM implementation backed up to /tmp/ (Phase 2 restore pending)
- Documentation covers atomic freelist conversion and benchmarking methodology

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-22 06:11:55 +09:00
7975e243ee Phase 7 Task 3: Pre-warm TLS cache (+180-280% improvement!)
MAJOR SUCCESS: HAKMEM now achieves 85-92% of System malloc on tiny
allocations (128-512B) and BEATS System at 146% on 1024B allocations!

Performance Results:
- Random Mixed 128B: 21M → 59M ops/s (+181%) 🚀
- Random Mixed 256B: 19M → 70M ops/s (+268%) 🚀
- Random Mixed 512B: 21M → 68M ops/s (+224%) 🚀
- Random Mixed 1024B: 21M → 65M ops/s (+210%, 146% of System!) 🏆
- Larson 1T: 2.68M ops/s (stable, no regression)

Implementation:
1. Task 3a: Remove profiling overhead in release builds
   - Wrapped RDTSC calls in #if !HAKMEM_BUILD_RELEASE
   - Compiler can eliminate profiling code completely
   - Effect: +2% (2.68M → 2.73M Larson)

2. Task 3b: Simplify refill logic
   - Use constants from hakmem_build_flags.h
   - TLS cache already optimal
   - Effect: No regression

3. Task 3c: Pre-warm TLS cache (GAME CHANGER!)
   - Pre-allocate 16 blocks per class at init
   - Eliminates cold-start penalty
   - Effect: +180-280% improvement 🚀

Root Cause:
The bottleneck was cold-start, not the hot path! First allocation in
each class triggered a SuperSlab refill (100+ cycles). Pre-warming
eliminated this penalty, revealing Phase 7's true potential.

Files Modified:
- core/hakmem_tiny.c: Pre-warm function implementation
- core/box/hak_core_init.inc.h: Pre-warm initialization call
- core/tiny_alloc_fast.inc.h: Profiling overhead removal
- core/hakmem_phase7_config.h: Task 3 constants (NEW)
- core/hakmem_build_flags.h: Phase 7 feature flags
- Makefile: PREWARM_TLS flag, phase7 targets
- CLAUDE.md: Phase 7 success summary
- PHASE7_TASK3_RESULTS.md: Comprehensive results report (NEW)

Build:
make HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 PREWARM_TLS=1 phase7-bench

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-08 12:54:52 +09:00
382980d450 Phase 6-2.4: Fix SuperSlab free SEGV: remove guess loop and add memory readability check; add registry atomic consistency (base as _Atomic uintptr_t with acq/rel); add debug toggles (SUPER_REG_DEBUG/REQTRACE); update CURRENT_TASK with results and next steps; capture suite results. 2025-11-07 18:07:48 +09:00
8f3095fb85 CI-safe debug runners: add ASan LD_PRELOAD + UBSan mailbox targets; add asan_preload script; document sanitizer-safe workflows and results in CURRENT_TASK.md (debug complete). 2025-11-07 12:09:28 +09:00
1da8754d45 CRITICAL FIX: TLS 未初期化による 4T SEGV を完全解消
**問題:**
- Larson 4T で 100% SEGV (1T は 2.09M ops/s で完走)
- System/mimalloc は 4T で 33.52M ops/s 正常動作
- SS OFF + Remote OFF でも 4T で SEGV

**根本原因: (Task agent ultrathink 調査結果)**
```
CRASH: mov (%r15),%r13
R15 = 0x6261  ← ASCII "ba" (ゴミ値、未初期化TLS)
```

Worker スレッドの TLS 変数が未初期化:
- `__thread void* g_tls_sll_head[TINY_NUM_CLASSES];`  ← 初期化なし
- pthread_create() で生成されたスレッドでゼロ初期化されない
- NULL チェックが通過 (0x6261 != NULL) → dereference → SEGV

**修正内容:**
全 TLS 配列に明示的初期化子 `= {0}` を追加:

1. **core/hakmem_tiny.c:**
   - `g_tls_sll_head[TINY_NUM_CLASSES] = {0}`
   - `g_tls_sll_count[TINY_NUM_CLASSES] = {0}`
   - `g_tls_live_ss[TINY_NUM_CLASSES] = {0}`
   - `g_tls_bcur[TINY_NUM_CLASSES] = {0}`
   - `g_tls_bend[TINY_NUM_CLASSES] = {0}`

2. **core/tiny_fastcache.c:**
   - `g_tiny_fast_cache[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_count[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_free_head[TINY_FAST_CLASS_COUNT] = {0}`
   - `g_tiny_fast_free_count[TINY_FAST_CLASS_COUNT] = {0}`

3. **core/hakmem_tiny_magazine.c:**
   - `g_tls_mags[TINY_NUM_CLASSES] = {0}`

4. **core/tiny_sticky.c:**
   - `g_tls_sticky_ss[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
   - `g_tls_sticky_idx[TINY_NUM_CLASSES][TINY_STICKY_RING] = {0}`
   - `g_tls_sticky_pos[TINY_NUM_CLASSES] = {0}`

**効果:**
```
Before: 1T: 2.09M   |  4T: SEGV 💀
After:  1T: 2.41M   |  4T: 4.19M   (+15% 1T, SEGV解消)
```

**テスト:**
```bash
# 1 thread: 完走
./larson_hakmem 2 8 128 1024 1 12345 1
→ Throughput = 2,407,597 ops/s 

# 4 threads: 完走(以前は SEGV)
./larson_hakmem 2 8 128 1024 1 12345 4
→ Throughput = 4,192,155 ops/s 
```

**調査協力:** Task agent (ultrathink mode) による完璧な根本原因特定

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-07 01:27:04 +09:00
f0c87d0cac Add Larson performance analysis and optimized profile
Ultrathink analysis reveals root cause of 4x performance gap:

Key Findings:
- Single-thread: HAKMEM 0.46M ops/s vs system 4.29M ops/s (10.7%)
- Multi-thread: HAKMEM 1.81M ops/s vs system 7.23M ops/s (25.0%)
- Root cause: malloc() entry point has 8+ branch checks
- Bottleneck: Fast Path is structurally complex vs system tcache

Files Added:
- LARSON_PERFORMANCE_ANALYSIS_2025_11_05.md: Detailed analysis with 3 optimization strategies
- scripts/profiles/tinyhot_optimized.env: CLAUDE.md-based optimized config

Proposed Solutions:
- Option A: Optimize malloc() guard checks (+200-400% expected)
- Option B: Improve refill efficiency (+30-50% expected)
- Option C: Complete Fast Path simplification (+400-800% expected)

Target: Achieve 60-80% of system malloc performance
2025-11-05 04:03:10 +00:00
52386401b3 Debug Counters Implementation - Clean History
Major Features:
- Debug counter infrastructure for Refill Stage tracking
- Free Pipeline counters (ss_local, ss_remote, tls_sll)
- Diagnostic counters for early return analysis
- Unified larson.sh benchmark runner with profiles
- Phase 6-3 regression analysis documentation

Bug Fixes:
- Fix SuperSlab disabled by default (HAKMEM_TINY_USE_SUPERSLAB)
- Fix profile variable naming consistency
- Add .gitignore patterns for large files

Performance:
- Phase 6-3: 4.79 M ops/s (has OOM risk)
- With SuperSlab: 3.13 M ops/s (+19% improvement)

This is a clean repository without large log files.

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-05 12:31:14 +09:00