Commit Graph

3 Commits

Author SHA1 Message Date
88717a8737 Phase 4 E1: ENV Snapshot Consolidation - GO (+3.92% avg, +4.01% median)
Target: Consolidate 3 ENV gate TLS reads → 1 TLS read
- tiny_c7_ultra_enabled_env():    1.28% self
- tiny_front_v3_enabled():        1.01% self
- tiny_metadata_cache_enabled():  0.97% self
- Total overhead: 3.26% self (perf profile analysis)

Implementation:
- core/box/hakmem_env_snapshot_box.h (new): ENV snapshot struct & API
- core/box/hakmem_env_snapshot_box.c (new): TLS snapshot implementation
- core/front/malloc_tiny_fast.h: Migrated 5 call sites to snapshot
- core/box/tiny_legacy_fallback_box.h: Migrated 2 call sites
- core/box/tiny_metadata_cache_hot_box.h: Migrated 1 call site
- core/bench_profile.h: Added hakmem_env_snapshot_refresh_from_env()
- Makefile: Added hakmem_env_snapshot_box.o to build
- ENV gate: HAKMEM_ENV_SNAPSHOT=0/1 (default: 0, research box)

A/B Test Results (Mixed, 10-run, 20M iters):
- Baseline (E1=0): 43,617,549 ops/s (avg), 43,562,895 ops/s (median)
- Optimized (E1=1): 45,327,239 ops/s (avg), 45,309,218 ops/s (median)
- Improvement: avg +3.92%, median +4.01%

Decision: GO (+3.92% >= +2.5% threshold)
- Action: Keep as research box (default OFF) for Phase 4
- Next: Consider promotion to default in MIXED_TINYV3_C7_SAFE preset

Design Rationale:
- Shape optimizations (B3, D3) reached saturation (+0.56% NEUTRAL)
- Shift to memory/TLS overhead optimization (new optimization frontier)
- Pattern: Similar to existing tiny_front_v3_snapshot (proven approach)
- Expected: +1-3% from 3.26% ENV overhead → Achieved: +3.92%

Technical Details:
- Consolidation: 3 TLS reads → 1 TLS read (66% reduction)
- Learner interlock: tiny_metadata_cache_eff pre-computed in snapshot
- Version sync: Refreshes on small_policy_v7_version_changed()
- Fallback safety: Existing ENV gates still available when E1=0

🤖 Generated with Claude Code

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-14 00:59:12 +09:00
deecda7336 Phase 3 C2: Slab Metadata Cache Optimization (3 patches) - NEUTRAL
Patch 1: Policy Hot Cache
- Add TinyPolicyHot struct (route_kind[8] cached in TLS)
- Eliminate policy_snapshot() calls (~2 memory ops saved)
- Safety: disabled when learner v7 active
- Files: tiny_metadata_cache_env_box.h, tiny_metadata_cache_hot_box.{h,c}
- Integration: malloc_tiny_fast.h route selection

Patch 2: First Page Inline Cache
- Cache current slab page pointer in TLS per-class
- Avoid superslab metadata lookup (1-2 memory ops)
- Fast-path in tiny_legacy_fallback_free_base()
- Files: tiny_first_page_cache.h, tiny_unified_cache.c
- Integration: tiny_legacy_fallback_box.h

Patch 3: Bounds Check Compile-out
- Hardcode unified_cache capacity as MACRO constant
- Eliminate modulo operation (constant fold)
- Macros: TINY_UNIFIED_CACHE_CAPACITY_POW2=11, CAPACITY=2048, MASK=2047
- File: tiny_unified_cache.h

A/B Test Results (Mixed, 10-run):
- Baseline (C2=0): 40.43M ops/s (avg), 40.72M ops/s (median)
- Optimized (C2=1): 40.25M ops/s (avg), 40.29M ops/s (median)
- Improvement: -0.45% (avg), -1.06% (median)
- DECISION: NEUTRAL (within ±1.0% threshold)
- Action: Keep as research box (ENV gate OFF by default)

Cumulative Gain (Phase 2-3):
- B3 (Routing shape): +2.89%
- B4 (Wrapper split): +1.47%
- C3 (Static routing): +2.20%
- C2 (Metadata cache): -0.45%
- Total: ~6.1% (from baseline 37.5M → 39.8M ops/s)

🤖 Generated with Claude Code

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-13 19:19:42 +09:00
0752688785 Phase REFACTOR-2: Legacy Fallback Logic Unification
Consolidate duplicated legacy free logic into a single reusable function.
Previously, hak_tiny_free_legacy_inline() and hak_tiny_free_legacy_impl()
contained identical implementations in malloc_tiny_fast.h and
tiny_c6_ultra_free_box.c.

Changes:
- NEW: core/box/tiny_legacy_fallback_box.h
  - tiny_legacy_fallback_free_base(): Unified legacy free implementation
  - Encapsulates: Unified Cache push + per-class stats + final fallback
  - Contract: BASE pointer input (already extracted from USER ptr)

- Modified: core/front/malloc_tiny_fast.h
  - Removed: hak_tiny_free_legacy_inline() (lines 96-111)
  - Replaced call: hak_tiny_free_legacy_inline → tiny_legacy_fallback_free_base

- Modified: core/box/tiny_c6_ultra_free_box.c
  - Removed: hak_tiny_free_legacy_impl() (lines 17-39)
  - Replaced call: hak_tiny_free_legacy_impl → tiny_legacy_fallback_free_base

Benefits:
- Single source of truth (DRY principle)
- Easier to maintain and test
- Consistent behavior across all free paths
- No performance impact (always_inline preserved)

No semantic changes - identical logic, just centralized.

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

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-11 19:01:59 +09:00