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3 Commits

Author SHA1 Message Date
Moe Charm (CI)
9b0d746407 Phase 3d-B: TLS Cache Merge - Unified g_tls_sll[] structure (+12-18% expected) 
Merge separate g_tls_sll_head[] and g_tls_sll_count[] arrays into unified
TinyTLSSLL struct to improve L1D cache locality. Expected performance gain:
+12-18% from reducing cache line splits (2 loads → 1 load per operation).

Changes:
- core/hakmem_tiny.h: Add TinyTLSSLL type (16B aligned, head+count+pad)
- core/hakmem_tiny.c: Replace separate arrays with g_tls_sll[8]
- core/box/tls_sll_box.h: Update Box API (13 sites) for unified access
- Updated 32+ files: All g_tls_sll_head[i] → g_tls_sll[i].head
- Updated 32+ files: All g_tls_sll_count[i] → g_tls_sll[i].count
- core/hakmem_tiny_integrity.h: Unified canary guards
- core/box/integrity_box.c: Simplified canary validation
- Makefile: Added core/box/tiny_sizeclass_hist_box.o to link

Build: ✅ PASS (10K ops sanity test)
Warnings: Only pre-existing LTO type mismatches (unrelated)

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

Co-Authored-By: Claude <noreply@anthropic.com>
 2025-11-20 07:32:30 +09:00
Moe Charm (CI)
030132f911 Phase 10: TLS/SFC aggressive cache tuning (syscall reduction failed) 
Goal: Reduce backend transitions by increasing frontend hit rate
Result: +2% best case, syscalls unchanged (root cause: SuperSlab churn)

Implementation:

1. Cache capacity expansion (2-8x per-class)
   - Hot classes (C0-C3): 4x increase (512 slots)
   - Medium classes (C4-C6): 2-3x increase
   - Class 7 (1KB): 2x increase (128 slots)
   - Fast cache: 2x default capacity

2. Refill batch size increase (4-8x)
   - Global default: 16 → 64 (4x)
   - Hot classes: 128 (8x) via HAKMEM_TINY_REFILL_COUNT_HOT
   - Mid classes: 96 (6x) via HAKMEM_TINY_REFILL_COUNT_MID
   - Class 7: 64 → 128 (2x)
   - SFC refill: 64 → 128 (2x)

3. Adaptive sizing aggressive parameters
   - Grow threshold: 80% → 70% (expand earlier)
   - Shrink threshold: 20% → 10% (shrink less)
   - Growth rate: 2x → 1.5x (smoother growth)
   - Max capacity: 2048 → 4096 (2x ceiling)
   - Adapt frequency: Every 10 → 5 refills (more responsive)

Performance Results (100K iterations):

Before (Phase 9):
- Performance: 9.71M ops/s
- Syscalls: 1,729 (mmap:877, munmap:852)

After (Phase 10):
- Default settings: 8.77M ops/s (-9.7%) ⚠️
- Optimal ENV: 9.89M ops/s (+2%) ✅
- Syscalls: 1,729 (unchanged) ❌

Optimal ENV configuration:
export HAKMEM_TINY_REFILL_COUNT_HOT=256
export HAKMEM_TINY_REFILL_COUNT_MID=192

Root Cause Analysis:

Bottleneck is NOT TLS/SFC hit rate, but SuperSlab allocation churn:
- 877 SuperSlabs allocated (877MB via mmap)
- Phase 9 LRU cache not utilized (no frees during benchmark)
- All SuperSlabs retained until program exit
- System malloc: 9 syscalls vs HAKMEM: 1,729 syscalls (192x gap)

Conclusion:

TLS/SFC tuning cannot solve SuperSlab allocation policy problem.
Next step: Phase 11 SuperSlab Prewarm strategy to eliminate
mmap/munmap during benchmark execution.

ChatGPT review: Strategy validated, Option A (Prewarm) recommended.

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

Co-Authored-By: Claude <noreply@anthropic.com>
 2025-11-13 14:25:54 +09:00
Moe Charm (CI)
707056b765 feat: Phase 7 + Phase 2 - Massive performance & stability improvements 
Performance Achievements:
- Tiny allocations: +180-280% (21M → 59-70M ops/s random mixed)
- Single-thread: +24% (2.71M → 3.36M ops/s Larson)
- 4T stability: 0% → 95% (19/20 success rate)
- Overall: 91.3% of System malloc average (target was 40-55%) ✓

Phase 7 (Tasks 1-3): Core Optimizations
- Task 1: Header validation removal (Region-ID direct lookup)
- Task 2: Aggressive inline (TLS cache access optimization)
- Task 3: Pre-warm TLS cache (eliminate cold-start penalty)
  Result: +180-280% improvement, 85-146% of System malloc

Critical Bug Fixes:
- Fix 64B allocation crash (size-to-class +1 for header)
- Fix 4T wrapper recursion bugs (BUG #7, #8, #10, #11)
- Remove malloc fallback (30% → 50% stability)

Phase 2a: SuperSlab Dynamic Expansion (CRITICAL)
- Implement mimalloc-style chunk linking
- Unlimited slab expansion (no more OOM at 32 slabs)
- Fix chunk initialization bug (bitmap=0x00000001 after expansion)
  Files: core/hakmem_tiny_superslab.c/h, core/superslab/superslab_types.h
  Result: 50% → 95% stability (19/20 4T success)

Phase 2b: TLS Cache Adaptive Sizing
- Dynamic capacity: 16-2048 slots based on usage
- High-water mark tracking + exponential growth/shrink
- Expected: +3-10% performance, -30-50% memory
  Files: core/tiny_adaptive_sizing.c/h (new)

Phase 2c: BigCache Dynamic Hash Table
- Migrate from fixed 256×8 array to dynamic hash table
- Auto-resize: 256 → 512 → 1024 → 65,536 buckets
- Improved hash function (FNV-1a) + collision chaining
  Files: core/hakmem_bigcache.c/h
  Expected: +10-20% cache hit rate

Design Flaws Analysis:
- Identified 6 components with fixed-capacity bottlenecks
- SuperSlab (CRITICAL), TLS Cache (HIGH), BigCache/L2.5 (MEDIUM)
- Report: DESIGN_FLAWS_ANALYSIS.md (11 chapters)

Documentation:
- 13 comprehensive reports (PHASE*.md, DESIGN_FLAWS*.md)
- Implementation guides, test results, production readiness
- Bug fix reports, root cause analysis

Build System:
- Makefile: phase7 targets, PREWARM_TLS flag
- Auto dependency generation (-MMD -MP) for .inc files

Known Issues:
- 4T stability: 19/20 (95%) - investigating 1 failure for 100%
- L2.5 Pool dynamic sharding: design only (needs 2-3 days integration)

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

Co-Authored-By: Claude <noreply@anthropic.com>
 2025-11-08 17:08:00 +09:00