Files
hakmem/core/box/tiny_ultra_classes_box.h
Moe Charm (CI) ea6ed1a6e4 Phase FREE-LEGACY-OPT-5-1/5-2: C5 ULTRA free+alloc integration
Summary:
========
Implemented C5 ULTRA TLS cache pattern following the successful C6 ULTRA design:
- Phase 5-1: Free-side TLS cache + segment learning
- Phase 5-2: Alloc-side TLS pop for complete free+alloc cycle integration

Targets C5 class (129-256B) as next legacy reduction after C6 completion.

Key Changes:
============

1. NEW FILES:
   - core/box/tiny_c5_ultra_free_box.h: C5 ULTRA TLS cache structure
   - core/box/tiny_c5_ultra_free_box.c: C5 free path implementation (same pattern as C6)
   - core/box/tiny_c5_ultra_free_env_box.h: ENV gating (HAKMEM_TINY_C5_ULTRA_FREE_ENABLED)

2. MODIFIED FILES:
   - core/front/malloc_tiny_fast.h:
     * Added C5 ULTRA includes
     * Added C5 alloc-side TLS pop at lines 186-194 (integrated with C6)
     * Added C5 free path at lines 333-337 (integrated with C6)

   - core/box/tiny_ultra_classes_box.h:
     * Added TINY_CLASS_C5 constant
     * Added tiny_class_is_c5() macro
     * Extended tiny_class_is_ultra() to include C5

   - core/box/free_path_stats_box.h:
     * Added c5_ultra_free_fast counter
     * Added c5_ultra_alloc_hit counter

   - core/box/free_path_stats_box.c:
     * Updated stats dump to output C5 counters

   - Makefile:
     * Added core/box/tiny_c5_ultra_free_box.o to all object lists

3. Design Rationale:
   - Exact copy of C6 ULTRA pattern (proven effective)
   - TLS cache capacity: 128 blocks (same as C6 for consistency)
   - Segment learning on first C5 free via ss_fast_lookup()
   - Alloc-side pop integrated directly in malloc_tiny_fast.h hotpath
   - Legacy fallback unification via tiny_legacy_fallback_free_base()

4. Expected Impact:
   - C5 legacy calls: 68,871 → 0 (100% elimination)
   - Total legacy reduction: ~53% of remaining 129,623
   - Mixed workload: Minimal regression (C5 is smaller class, fewer allocations)

5. Stats Collection:
   Run with: HAKMEM_TINY_C5_ULTRA_FREE_ENABLED=1 HAKMEM_FREE_PATH_STATS=1 ./bench_allocators_hakmem

   Expected output:
   [FREE_PATH_STATS] ... c5_ultra_free=68871 c5_ultra_alloc=68871 ... legacy_fb=60752 ...
   [FREE_PATH_STATS_LEGACY_BY_CLASS] ... c5=0 ...

Status:
=======
- Code:  COMPLETE (3 new files + 5 modified files)
- Compilation:  Verified (no errors, only unused variable warnings unrelated to C5)
- Functionality: Ready to benchmark (ENV gating: default OFF, opt-in via ENV)

Phase Progression:
==================
 Phase 4-4: C6 ULTRA free+alloc (legacy C6: 137,319 → 0)
 Phase 5-1/5-2: C5 ULTRA free+alloc (legacy C5: 68,871 → 0 expected)
 Phase 4.5: C4 ULTRA (34,727 remaining)
📋 Future: C3/C2 ULTRA if beneficial

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

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2025-12-11 19:26:51 +09:00

16 lines
578 B
C

#ifndef HAKMEM_TINY_ULTRA_CLASSES_BOX_H
#define HAKMEM_TINY_ULTRA_CLASSES_BOX_H
// Purpose: Named constants for ULTRA tier classes (C5, C6, C7)
#define TINY_CLASS_C5 5
#define TINY_CLASS_C6 6
#define TINY_CLASS_C7 7
// Helper macros for class checking
#define tiny_class_is_c5(idx) ((idx) == TINY_CLASS_C5)
#define tiny_class_is_c6(idx) ((idx) == TINY_CLASS_C6)
#define tiny_class_is_c7(idx) ((idx) == TINY_CLASS_C7)
#define tiny_class_is_ultra(idx) (tiny_class_is_c5(idx) || tiny_class_is_c6(idx) || tiny_class_is_c7(idx))
#endif // HAKMEM_TINY_ULTRA_CLASSES_BOX_H